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Endangered and Threatened Wildlife and Plants; Determination of Threatened Status for the Western Distinct Population Segment of the Yellow-billed Cuckoo (Coccyzus americanus)
CFR Part: "50 CFR Part 17"
RIN Number: "RIN 1018-AY53"
Citation: "79 FR 59992"
Document Number: "Docket No. FWS-R8- ES-2013-0104; 4500030113"
Page Number: "59992"
"Rules and Regulations"
SUMMARY: We, the
DATES: This rule is effective
ADDRESSES: This final rule is available on the Internet at http://www.regulations.gov and at the Sacramento Fish and Wildlife Office at http://www.fws.gov/sacramento/. Comments and materials received, as well as supporting documentation used in the preparation of this rule, will be available for public inspection, by appointment, during normal business hours at:
FOR FURTHER INFORMATION CONTACT:
Why we need to publish a rule. Under the Endangered Species Act, a species may warrant protection through listing if it is endangered or threatened throughout all or a significant portion of its range. Listing a species as an endangered or threatened species can only be completed by issuing a rule. On
The basis for our action. Under the Endangered Species Act, we can determine that a species is an endangered or threatened species based on any of five factors: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; or (E) other natural or manmade factors affecting its continued existence.
We have determined that the western yellow-billed cuckoo meets the definition of a threatened species and is likely to become endangered throughout its range within the foreseeable future, based on the immediacy, severity, and scope of the threats to its continued existence. These include habitat loss associated with manmade features that alter watercourse hydrology so that the natural processes that sustained riparian habitat in western
What the rule does. We are making a final listing determination regarding the western distinct population segment of the U.S. population of the yellow-billed cuckoo pursuant to the Endangered Species Act. This species occurs in the western
Peer review and public comment. We sought comments from independent specialists to ensure that our determination is based on scientifically sound data, assumptions, and analyses. We invited these peer reviewers to comment on our listing proposal. We also considered all other comments and information we received during the three open comment periods. We have considered and incorporated any pertinent information from all comments and information we received into this final rule. See the Summary of Comments and Recommendations section, below, for a summary of comments we received on the proposed listing.
Previous Federal Actions
We proposed critical habitat for the western DPS of the yellow-billed cuckoo on
In this section of the final rule, it is our intent to discuss only those topics directly relevant to the listing of the western yellow-billed cuckoo as a threatened species. Please refer to the proposed listing rule for the western yellow-billed cuckoo for detailed background and species information (78 FR 61621;
The yellow-billed cuckoo (Coccyzus americanus) is a member of the avian family Cuculidae and is a Neotropical migrant bird that winters in
Adult yellow-billed cuckoos have a fairly stout and slightly down-curved bill; a slender, elongated body with a long-tailed look; and a narrow yellow ring of colored, bare skin around the eye. The plumage is loose and grayish-brown above and white below, with reddish primary flight feathers. The tail feathers are boldly patterned with black and white below. They are a medium-sized bird about 12 inches (in) (30 centimeters (cm)) in length, and about 2 ounces (oz) (60 grams (g)) in weight. The bill is blue-black with yellow on the basal half of the lower mandible. The legs are short and bluish-gray. All cuckoos have a zygodactyl foot with two toes pointing forwards and two toes pointing backwards. Juvenile yellow-billed cuckoos resemble adults, except the tail patterning is less distinct and the lower bill has little or no yellow. Males and females differ slightly and are indistinguishable in the field (Hughes 1999, pp. 2-3).
Typically a secretive and hard-to-detect bird, adult yellow-billed cuckoos have a distinctive "kowlp" call, which is a loud, nonmusical series of notes that slows down and slurs toward the end. Yellow-billed cuckoos advertise for a mate using a series of soft "cooing" notes, which they give at night as well as during daytime. Both members of a pair use a soft knocking call as a contact or warning call near the nest (Hughes 1999, pp. 8-9). Please refer to the
Recent research on yellow-billed cuckoo genetics using mitochondrial DNA did not find any fixed genetic differences between eastern and western yellow-billed cuckoos (Farrell 2013, pp. 165-170). The author concluded that the separation into distinct subspecies may be too recent to be expressed in a single mitochondrial gene and recommended future studies using next-generation sequencing techniques. Avian geneticist
Distinct Vertebrate Population Segment Analysis
Under the Act, we must consider listing any species, subspecies, or, for vertebrates, any DPS of these taxa if there is sufficient information to indicate that such action may be warranted. To implement the measures prescribed by the Act and its Congressional guidance, we (along with the
Before we can evaluate whether a given population segment is a DPS under the Act, we must first determine if any population segments exist for the vertebrate species. As discussed in the Taxonomy section of the proposed rule (78 FR 61621;
To establish the range of the population segment under consideration, we used the area occupied by the western yellow-billed cuckoo (the subspecies) originally defined by
The geographical breeding range of the yellow-billed cuckoo in western
See Illustration in Original Document.
Under our DPS policy, three elements are considered in a decision regarding the status of a possible DPS as endangered or threatened under the Act. The elements are: (1) Discreteness of the population segment in relation to the remainder of the species to which it belongs; (2) the significance of the population segment to the species to which it belongs; and (3) the population segment's conservation status in relation to the Act's standards for listing. In other words, if we determine that a population segment of a vertebrate species being considered for listing is both discrete and significant, we would conclude that it represents a DPS, and thus a "species" under section 3(16) of the Act, whereupon we would evaluate the level of threat to the DPS based on the five listing factors established under section 4(a)(1) of the Act to determine whether listing the DPS as an "endangered species" or a "threatened species" is warranted.
Below, we evaluate under our DPS policy whether the population segment of yellow-billed cuckoos that occurs in the western
Under our DPS Policy, a population segment of a vertebrate species may be considered discrete if it satisfies either of the following two conditions: (1) It is markedly separated from other populations of the same taxon as a consequence of physical, physiological, ecological, or behavioral factors (quantitative measures of genetic or morphological discontinuity may provide evidence of this separation); or (2) it is delimited by international governmental boundaries within which significant differences in control of exploitation, management of habitat, conservation status, or regulatory mechanisms exist that are significant in light of section 4(a)(1)(D) of the Act.
The analysis of the population segment of the yellow-billed cuckoo in western
Yellow-billed cuckoos historically bred at the southern tip of
In the northern
The separation of the western yellow-billed cuckoo population segment from yellow-billed cuckoos in the eastern population segment continues south along the crest of the Rockies into southern
From this information we concluded that the Chihuahua-
Eastern and western yellow-billed cuckoos are highly migratory, and the two populations may spend winters in overlapping regions in
Data collected from publications and other sources demonstrate the existence of behavioral differences between yellow-billed cuckoos in the east and west.
Yellow-billed cuckoo populations in the east and west differ in the timing of arrival on the breeding grounds in the spring. Yellow-billed cuckoos in western
Information, including timing of migration, indicates that yellow-billed cuckoos from
Based on migration timing, yellow-billed cuckoos split into two populations. This split occurs along the line that corresponds with the traditional subspecies boundary (see Figure 1, above).
Continental Divide (as defined above) in
Under our DPS policy, the standard for discreteness does not require absolute separation because this can rarely be demonstrated for any population of organism. For the yellow-billed cuckoo populations in western
Under our DPS policy, once we have determined that a population segment is discrete, we consider its biological and ecological significance to the larger taxon to which it belongs. Our DPS policy provides several potential considerations that may demonstrate the significance of a population segment to the remainder of its taxon, including: (1) Evidence of the persistence of the discrete population segment in an ecological setting unusual or unique for the taxon, (2) evidence that loss of the discrete population segment would result in a significant gap in the range of the taxon, (3) evidence that the population segment represents the only surviving natural occurrence of a taxon that may be more abundant elsewhere as an introduced population outside its historic range, or (4) evidence that the discrete population segment differs markedly from the remainder of the species in its genetic characteristics.
We have found substantial evidence that two of these four significance criteria (numbers 2 and 4) are met by the discrete population segment of yellow-billed cuckoos that occurs west of the
Evidence That Loss of the Discrete Population Segment Would Result in a Significant Gap in the Range of the Taxon
Loss of the discrete population segment would result in a significant gap in the range of the taxon because an extensive area would be without yellow-billed cuckoos if the western population segment were lost. Seven entire States and substantial portions of five additional States in
Evidence That the Discrete Population Segment Differs Markedly From Other Populations of the Species in Its Genetic Characteristics
Data collected from publications and other sources demonstrate the existence of morphological and physiological differences between yellow-billed cuckoos in the east and west. Morphologically, the yellow-billed cuckoos in western
One peer reviewer measured 35 cuckoos from the Rio Grande and 25 cuckoos from the
Other physical and morphological differences exist between yellow-billed cuckoos in the east and west, and provide additional evidence of ecological significance. These include:
* Yellow-billed cuckoos in western
* Juvenile yellow-billed cuckoos in the east have yellow bills (Oberholser and
* Adult yellow-billed cuckoos in the west have a lower mandible that is orange-yellow, while yellow-billed cuckoos in the east have lower mandibles that are bright yellow (Franzreb and Laymon 1993, p. 26; Laymon 2000, in litt., p. 14).
* As noted previously, adult yellow-billed cuckoos in the west are larger and heavier, on average, than adult yellow-billed cuckoos in the east. More than 80 percent of individuals can be assigned to east or west based on morphological measurements (see also Oberholser and
Information, including morphology, indicates that yellow-billed cuckoos from
Based on morphological measurements, bill color of young and adults, egg size and weight, and migration timing, yellow-billed cuckoos split into two populations. This split occurs along the line that corresponds with the traditional subspecies boundary (see Figure 1, above). Phenotypically or outwardly expressed traits present substantial evidence that the western population segment of yellow-billed cuckoo differs markedly from other populations of the species.
However, the strongest evidence of differences between yellow-billed cuckoos in the western population segment and those of the east in genetic characteristics is the difference in timing of migrations. This difference can only have developed as an evolved trait in response to environmental factors over a long period of time, and thus is genetically linked (Cresswell et al. 2011, pp. 13-15; Pulido et al. 2001). As previously discussed, the difference in size of yellow-billed cuckoos between east and west, as well as differences in size, weight, and shell thickness of eggs, are also evolved genetically linked traits. As discussed in the
The best available information indicates that the discrete yellow-billed cuckoo population segment that nests west of the
Based on the best scientific and commercial data available on distribution as well as behavioral and morphological characteristics of the species, we have determined that the western population segment of the yellow-billed cuckoo is both discrete and significant per our DPS policy. Therefore, we conclude that the western distinct population segment of the yellow-billed cuckoo is a DPS, and thus a "species" under section 3(16) of the Act. Our determination of biological and ecological significance is appropriate because the population segment has a geographical distribution that is biologically meaningful.
The term "distinct population segment" is not commonly used in scientific discourse. As such, and in contrast to taxonomically defined species and subspecies, there is no established name for the western distinct population segment of the yellow-billed cuckoo in the available literature; we will refer to this "species" (DPS) as the western yellow-billed cuckoo. The range of the western yellow-billed cuckoo in
See Illustration in Original Document.
Summary of Comments and Recommendations
In the proposed rule published on
During the comment periods for the proposed rule, we received 34,459 comment letters directly addressing the proposed listing of the western DPS of the yellow-billed cuckoo as a threatened species. The vast majority of these comment letters voiced their support or opposition to the action, but did not provide significant supporting information on the proposed listing. A total of 34,380 letters were in support of the listing, while 54 letters were in opposition to listing, with 25 commenters providing additional information, but took no position on the listing of the species. Approximately 141 of these comment letters provide additional information or comments. All substantive information provided during comment periods has either been incorporated directly into this final determination or is addressed below.
In accordance with our peer review policy published on
We reviewed all comments we received from the peer reviewers for substantive issues and new information regarding the listing of the western DPS of the yellow-billed cuckoo. The peer reviewers generally concurred with our methods and conclusions, and provided additional information, clarifications, and suggestions to improve the final rule. Peer reviewer comments are addressed in the following summary and incorporated into the final rule as appropriate.
Peer Reviewer Comments
(1) Comment: One reviewer discussed the heritability of migration timing, indicating that the difference in migration timing between eastern and western cuckoos is reflective of genetic differences and added a supportive reference (Pulido et al. 2001).
Our Response: In the proposed and this final rule, we outlined our reasoning for determining that the western populations of the yellow-billed cuckoo constitute a valid DPS (see Distinct Vertebrate Population Segment Analysis, above). In our determination, we relied on behavioral and morphological and other characteristics of the species to support separation and distinctness from yellow-billed cuckoos in the east. Although genetics most likely play a role in behavioral and morphological aspects of a species, in our determination we did not rely on specific genetic information or separation to come to our conclusion. The views of the peer reviewer and the information they provided (Pulido et al. 2001, pp. 149-158) further support our conclusions reached in determining a valid DPS for the western yellow-billed cuckoo. We revised this final rule to include the information provided.
(2) Comment: One reviewer stated that a close examination of the DNA studies conducted on cuckoos to date would infer a deeper genetic divergence between western and eastern cuckoos than presented in the proposed rule and that further analysis would likely support division of species into two subspecies. The reviewer also provided a critique of the techniques used in the studies to date, noting that markers used in all three genetics studies evolve too slowly to reveal genetic structure within the species, and that the choice of outgroup for study comparison was flawed in one study.
Our Response: See response to Comment 1 above for a discussion of how we used genetic information in our DPS determination. Although we agree that further studies and information on the genetics for the yellow-billed would assist in further validating our determination of separation between eastern and western yellow-billed cuckoo populations, we must rely on the best scientific or commercial data available to make our listing determinations. We appreciate the information provided and have made some revisions to the DPS analysis to incorporate citations provided by the peer reviewer, as needed.
(3) Comment: Two reviewers indicated that recent research has shown that vocalizations cannot be reliably used to determine the sex of cuckoos in the field. Two public commenters also raised this concern.
Our Response: We concur and have revised the text to clarify information on vocalizations for the western yellow-billed cuckoo.
(4) Comment: One reviewer indicated that the habitat section could be strengthened by presenting habitat models that have been developed. This reviewer suggested that the presentation of tamarisk as a habitat component could be improved by using information from several references from research on the
Our Response: Based on observations of western yellow-billed cuckoos, we have identified riparian trees including willow (Salix sp.),
(5) Comment: One reviewer suggested that estimates of breeding populations of western yellow-billed cuckoos may be overestimates and the numbers may be even lower than indicated in the proposed rule.
Our Response: We are aware of the difficulties in obtaining accurate counts of western yellow-billed cuckoos. Survey methods for western yellow-billed cuckoos have evolved over time since the first play-back surveys were conducted in
Obtaining accurate survey results are made more difficult because: (1) Western yellow-billed cuckoos often have helper males at the nest; (2) they are only loosely territorial; (3) nests of adjacent pairs can be very close to each other; (4) female western yellow-billed cuckoos often lay a second and third clutch sometimes with different mates; and (5) it is likely that they move from one river system to another between clutches. These unusual behaviors can lead to either an over count or an under count of individuals, pairs, or territories.
Many of the earlier population estimates were made of pairs of western yellow-billed cuckoos. For the reasons listed above, some recent researchers have decided that it is more accurate to use the term territories rather than pairs. An assessment of the methodology used to determine pairs in the older studies and territories in the more recent studies concludes that very similar methodology is used and that the numbers are comparable.
In some cases, we were able to use the original survey data and simply compare the number of survey hours and number of western yellow-billed cuckoos surveyed and compare them from one year to the next and one time period to another. This is a very reliable and accurate method of comparison. In other cases, such as that at the
We have taken all of these difficulties and changes of survey methods and changes of data and behavior interpretation into account in our assessment of survey results and western yellow-billed cuckoo population trends. We have used the best available data and science in determining population estimates and trends. Because we have been aware of the changes in survey methods and have factored that information into our analysis, we are confident that our estimates of breeding populations are accurate.
(6) Comment: One reviewer indicated that habitat use separates eastern and western cuckoos; observations suggest that in eastern
Our Response: We have considered this information in our determination of the DPS for the yellow-billed cuckoo. Although credible observations of species behavior are valuable, peer-reviewed published materials would further support these observations, and additional research on this topic would be valuable. The information provided will be considered further in the development of the final critical habitat designation for the species and in recovery planning.
(7) Comment: Two reviewers suggested that the section on climate change could be condensed and that uncertainties in forecasting precipitation could bog down conservation actions that would clearly benefit western yellow-billed cuckoos in the near future.
Our Response: The Service used the climate change information that was available in the literature. Because the western DPS of the yellow-billed cuckoo covers such a large area, the effects of climate change will be different in the various regions. The
(8) Comment: One reviewer provided survey results indicating that western yellow-billed cuckoos have been detected along the San Juan and Green rivers in
Our Response: We appreciate this additional information and have considered this in our listing determination. This information will also be considered in our final critical habitat designation.
(9) Comment: One reviewer commented that a potential planned activity is the reallocation of water from the
Our Response: We appreciate this additional information and have considered this in our listing determination. This information will also be useful in recovery planning and implementation.
(10) Comment: One reviewer provided information that describes the ecological cascade process that leads to loss of western yellow-billed cuckoo habitat in riparian areas. The peer reviewer stated that the key to sustaining western yellow-billed cuckoo habitat is maintaining an ongoing process of new land creation and flow patterns conducive to colonization of willow and cottonwood. The peer reviewer also noted that it is problematic that a
Our Response: We appreciate this additional information and have considered this in our listing determination. The information will be helpful when developing a recovery plan for the western yellow-billed cuckoo.
(11) Comment: One reviewer adds an additional pervasive threat is the design of open channel flood control channels with inappropriately smooth roughness coefficients. This over-scours the floodplains and requires removal of woody riparian vegetation that regenerates on floodplains. This leads to floodplains with no western yellow-billed cuckoo habitat.
Our Response: We have added this information to section "Encroachment of Levees and Flood Control and Bank Stabilization Structures into the River Channel and Floodplain" in the Factor A discussion in this final rule.
(12) Comment: One reviewer provides information on several additional projects that he indicates are impacting western yellow-billed cuckoo habitat. The reviewer notes that the
Our Response: We appreciate this additional information and have considered this in our listing determination. This information will be helpful in developing and implementing the recovery plan for the species.
(13) Comment: One reviewer indicated that in Conservation Efforts section under the Factor E discussion, a distinction should be made between "active" restoration and "process-based" restoration.
Our Response: We have revised the text in the section to clarify the difference in types of restoration activities.
(14) Comment: One reviewer measured 35 cuckoos from the Rio Grande and 25 cuckoos from the
Our Response: We thank the reviewer for this information. However, we are concerned that the measurements may have been taken incorrectly for the following reasons. We first note that, with the exception of wing measurements, accurate measurements are hard, if not impossible, to obtain from live birds under field conditions. We are concerned that in the given sample, bill-depth measurements may have been measured incorrectly because all individuals measured, regardless of area of origin, had deeper bills than any of the cuckoos measured by Banks (1988, pp. 473-477) or Franzreb and Laymon (1993, pp. 17-28). It is likely that these measurements were taken on an incorrect location on the bill. We note that several of the bill-length measurements reported were also record lengths for cuckoos, regardless of origin and suspect that they too were likely measured incorrectly. The use of these incorrect measurements in the DFA equations would be expected to yield incorrect "likely area of origin." Therefore, we have not used this information in our final listing determination.
Federal Agency Comments
During the development of the proposed and this final listing rule, we coordinated with Federal agencies and asked for their input on the information presented and any concerns they may have. We have not included specific comments and responses to
(15) Comment: The
Our Response: We appreciate receiving the information on
(16) Comment: The USACE provided references that deal with southwestern willow flycatcher (Empidonax traillii extimus) consultations and management at
Our Response: Although specific project activities may require additional review and potentially result in formal consultation for various Federal actions, it is reasonable to assume that the conservation plan and associated conservation easements for the southwestern willow flycatcher may provide habitat protections for the western yellow-billed cuckoo. However, consultation with the Service will not likely result in operation decisions that would cause a risk of loss of human life or cause significant impacts to downstream economies. We have been coordinating with the USACE on their activities and dam operation at
Our Response: We appreciate the additional information provided by the USFS and have considered it or incorporated changes to language into our final listing determination. Well-controlled grazing activity can be compatible within riparian zones and in western yellow-billed cuckoo habitat depending on the conservation measures implemented for the grazing activity. The amount of management depends on the sensitivity of the habitat at any given location and would most likely need to be managed on a site-by-site basis. For example, a grazing regime used on Audubon California's
(18) Comment: The
Our Response: We appreciate this additional information and have considered this in our listing determination. NRCS' cooperation and assistance will be very helpful during the recovery phase for the species.
Our Response: We appreciate this additional information and have considered this in our listing determination. Restoration of riparian habitat will be an important phase in the recovery of the western yellow-billed cuckoo. This information will also be helpful in the development and implementation of a recovery plan for the western yellow-billed cuckoo.
(20) Comment: The USDA NRCS in
Our Response: According to section 4(b)(1)A) of the Act, we are to base our listing determinations solely on the basis of the best scientific and commercial data available as they relate to the five factors listed in section 4(a)(1) of the Act. The consideration of economics is only related to the designation of critical habitat under section 4(b)(2) of the Act.
Comments From States
Section 4(i) of the Act states, "the Secretary shall submit to the State agency a written justification for his failure to adopt regulations consistent with the agency's comments or petition." Comments received from the States regarding the proposal to list as a "threatened species" for the western DPS of the yellow-billed cuckoo are addressed below. We received 17 comment letters from 17 State agencies in 11 States. Of the 17 letters submitted, 9 were from State wildlife agencies. We did not receive comments from the
Our Response: We appreciate this additional information and have considered this in our final listing determination. This habitat information has been discussed in detail in our proposed critical habitat designation. See the proposed critical habitat rule for the western yellow-billed cuckoo published in the
(22) Comment: The
Our Response: We appreciate this additional information and have considered this in our listing determination. This information will also be considered in our final critical habitat designation.
Our Response: The Act does not specifically define the term "foreseeable future," and does not require the Service to quantify the time period of foreseeable future in making listing determinations. The Solicitor for the
In considering the foreseeable future as it relates to the status of the western yellow-billed cuckoo, we considered the factors acting on the species and looked to see if reliable predictions about the status of the species in response to those factors could be drawn. We considered the historical data to identify any relevant existing trends that might allow for reliable prediction of the future conservation status of the species (in the form of extrapolating the trends). We also considered whether we could reliably predict any future events that might affect the status of the species, recognizing that our ability to make reliable predictions into the future is limited by the variable quantity and quality of available data. Available population information for western yellow-billed cuckoo is limited for determining trends because no long-term rangewide status survey has been completed and the threats facing the species are variable in intensity and scope across the species' range and do not reliably provide a sound basis for specific timeframe predictions. The available data do not allow us to determine a specific timeframe for the foreseeable future for the western yellow-billed cuckoo; therefore, we rely on a qualitative assessment of the foreseeable future, in terms of that period of time over which we can reasonably predict the future population trends and threats to the species, and the likely consequences of those threats and trends for the status of the species. We have discussed the timeframe for when we have determined the threats are acting on the species under each factor in the Summary of Factors Affecting the Species and in our Determination sections below.
Our Response: We are aware of the limited number of sightings for the species in western Montana and other areas within the DPS. However, we consider yellow-billed cuckoos that are found in the portion of Montana west of the
Our Response: As stated in the proposed rule and this final rule, we agree that the number of western yellow-billed cuckoos nesting in
Our Response: We appreciate the review and support of the
Our Response: We appreciate this additional information and have considered this in our listing determination. This information will also be used in the development of our final critical habitat designation and implementation of a recovery plan for the western yellow-billed cuckoo.
Our Response: The Service agrees that tamarisk is a major threat to the western yellow-billed cuckoo's habitat. We expect that in areas where restoration of native riparian vegetation is possible, removal of tamarisk would be considered a net benefit, as native riparian vegetation has a greater habitat value for the western yellow-billed cuckoo. If western yellow-billed cuckoos are documented to use an area slated for tamarisk removal, consultation with the Service may be necessary in order to jointly develop appropriate measures to avoid or minimize the potential for adverse effects to the western yellow-billed cuckoo. However, the process of listing a species as threatened under the Act is not designed to curtail projects that have the potential to benefit that species, and it is unlikely that beneficial tamarisk removal and riparian restoration projects would be negatively impacted from listing the western yellow-billed cuckoo. At this time, we are not developing a rule under section 4(d) of the Act for this species.
(29) Comment: The Director for the Utah Public Lands Policy Coordination Office stated that: (a)
Our Response: We commend the
We disagree that the DPS line is arbitrary. The DPS line used to separate the western yellow-billed cuckoo from yellow-billed cuckoos in the east in the vicinity of
We received GIS data from the
Our Response: We appreciate this additional information and have considered this in our listing determination. This cooperation in recovering the species will be important in the development and implementation of a recovery plan for the species.
(31) Comment: The Water Resources Division of the
Our Response: Riparian systems in
Our Response: We appreciate this additional information and have considered this in our DPS analysis and listing determination. Morphological information is just one of the reasons we have determined that the western yellow-billed cuckoo is a valid DPS under our policy. In order to be more transparent in describing our rationale for our DPS determination, we included the morphological information as further evidence of the DPS. We conclude that including morphological information in the DPS Significance section helps to provide a complete picture of the differences between eastern and western yellow-billed cuckoos.
Our Response: Some restoration projects, especially where existing poor-quality, tamarisk-dominated habitat that is occupied by western yellow-billed cuckoo is being removed and higher quality, willow-cottonwood or mesquite habitat is being planted, may require consultation with the Service in order to jointly develop appropriate measures to avoid or minimize the potential for adverse effects to the western yellow-billed cuckoo. However, the process of listing a species as threatened under the Act is not designed to curtail projects that have the potential to benefit that species, and it is unlikely that beneficial tamarisk removal and riparian restoration projects would be negatively impacted from listing the western yellow-billed cuckoo. It is more likely that listing the western yellow-billed cuckoo will complement the recovery efforts and potentially provide additional sources of funding through section 6 of the Act.
Our Response: Most locations in
While the results of the riparian restoration work on the
We have added citations in this final rule that show that western yellow-billed cuckoos have declined as a result of riparian habitat loss and degradation (see section in Factor A discussion). We have concluded that this is a well-documented pattern in
To date it is difficult to quantify the benefit of riparian habitat restoration to western yellow-billed cuckoo populations. Most restoration efforts are carried out on a small scale in comparison to the home-range size of the western yellow-billed cuckoo. In the
(35) Comment: New Mexico Game and Fish requested a delay in listing so that more research can be conducted in
Our Response: In making listing determinations under the Act, we are to rely solely on the best scientific and commercial data currently available. Our DPS policy outlines the criteria for determination of whether a segment of a vertebrate species population qualifies as a DPS. In reviewing the most current information available, we have determined that the western DPS of the yellow-billed cuckoo is valid and meets the criteria outlined in our policy. As we stated above in the Distinct Vertebrate Population Segment Analysis section, we understand that the area in southern
As discussed above in Comment 14, one peer reviewer measured yellow-billed cuckoos on the Rio Grande and
(36) Comment: New Mexico Game and Fish and several other commenters suggest that western yellow-billed cuckoos have been found at elevations higher than reported in the proposed rule.
Our Response: We appreciate this additional information and have considered this in our listing determination. Most of these higher elevation sightings in the
(37) Comment: New Mexico Game and Fish would like us to develop a rule under section 4(d) of the Act to allow for economic and agricultural growth in conjunction with conservation efforts, especially while developing the State's comprehensive conservation program.
Our Response: Section 4(d) of the Act allows the Secretary the discretion to issue such regulations as [s]he deems necessary and advisable to provide for the conservation of a species. The Service's standard policy (under 50 CFR 17.31(a)) for issuing prohibitions for threatened species is to apply all the prohibitions of an endangered species to a threatened species unless otherwise revoked by issuance of more specific prohibitions. In the case of the western yellow-billed cuckoo, we are in the process of reviewing whether the "standard" prohibitions apply or whether more specific prohibitions are appropriate. If we determine that more specific prohibitions apply and that they are necessary and advisable to provide for the conservation of the western yellow-billed cuckoo, we will issue a proposed rule under section 4(d) of the Act for public comment. However at this time, we do not have and the commenter did not provide enough information on whether a section 4(d) rule for agricultural activities is appropriate. We would be available for future discussion on potentially developing measures to maximize the conservation value of agricultural practices and develop some type of conservation mechanism with the commenter in the future; however, due to time constraints for developing a final rule we cannot currently develop and implement such measures.
(38) Comment: New Mexico Game and Fish stated that there was a large discrepancy between population estimates of 100-155 pairs for western
Our Response: The Partners in Flight Web site for
(39) Comment: The
Our Response: Listing of the western yellow-billed cuckoo under the Act is based on the species' population status and trends, and the threats to the species. Recovery of a species will be based on criteria developed by the Recovery Team once it becomes established. Solving the threats to the western yellow-billed cuckoo is an important part of the recovery process, and watershed health will be very important when developing recovery criteria and implementing recovery actions.
Our Response: Although the identification of the western yellow-billed cuckoo by the
Our Response: The disruption and changes to "natural" river and stream processes, which help the development and regeneration of riparian vegetation, have been identified as a threat to the species. The majority of streams and water delivery facilities within the range of the western yellow-billed cuckoo are at least partly managed by Federal entities or proposed activities that would have a Federal nexus. As a result, these Federal agencies have an obligation under section 7 the Act to conserve endangered or threatened species and their habitat. Section 4(d) of the Act states that the Secretary shall issue such regulations as [s]he deems necessary and advisable to provide for the conservation of any threatened species. New projects on Federal land or funding by the Federal government will be subject to section 7 consultations, as will reauthorization of Federal projects. Because of the interrelatedness between water management, the health of riparian habitat, and the dependence of riparian habitat by the western yellow-billed cuckoo, we are not currently considering a rule under section 4(d) of the Act for this species to limit the prohibitions of the Act for ongoing and future water management activities.
Our Response: Caterpillar and other insect populations can be affected by health of the riparian habitat, tree and shrub species in the riparian zone, and pesticide use (e.g., pesticide drift into the riparian zone or applying pesticides directly on the riparian zone). All of these factors are influenced by human activities at some level. Lack of an adequate food supply is a major threat for the western yellow-billed cuckoo.
Our Response: We appreciate the
We agree that climate change projections and prediction can be difficult due to the availability of information and variability of climate and habitat conditions over time. However, in a study looking at the recent effects of climate change on temperature and precipitation over the past 36+ years (1970-2006), Enquist et al. (2008, pp. 1-32) found that in
Our Response: Western yellow-billed cuckoos do not rely on tamarisk in the same way that southwestern willow flycatchers do. Western yellow-billed cuckoos may on rare occasions nest in tamarisk, but they forage almost entirely in native riparian habitat. Western yellow-billed cuckoos are primarily dependent on large caterpillars, which depend on cottonwoods and willows and are not found on tamarisk. On the other hand, southwestern willow flycatchers feed on small flying insects and both nest and forage in tamarisk as long as water or super-saturated soil is in the vicinity of the nest and flying insects are available. In areas where the hydrology is still intact and will support native riparian habitat, the tamarisk beetle could assist in the restoration of the riparian zone. In areas that can no longer support willows, cottonwoods, and mesquite, the beetle could suppress the tamarisk to the point that western yellow-billed cuckoos will no longer use the habitat. In this latter case, the tamarisk beetle could be considered a threat, as spontaneous regeneration of native vegetation is difficult due to the degraded nature of the habitat and disrupted hydrologic conditions.
(45) Comment: The Deputy Commissioner for the
Our Response: Under section 4(a)(1) of the Act, we are to determine if a species is endangered or threatened based on one of five listing factors. Economics or loss of revenue is not one of the factors used in determining if a species should be listed. Although we understand that listing a species as either endangered or threatened causes some regulatory oversight and the potential need for consultation, we are obligated to make such determinations solely on the threats facing the species or its habitat. Listing a species does not mean projects cannot proceed, it only means they must be implemented in a manner that still conserves the species and its habitat. In addition, because the species occurs in riparian habitat along streams, it is most likely that projects involving the development of oil, gas, wind, and solar projects would not result in significant direct impacts on the species, as these projects typically do not occur in riparian corridors.
We believe we have used the best scientific and commercial information available in coming to our decision to list the western yellow-billed cuckoo as a threatened species. The western yellow-billed cuckoo has been a candidate for listing since 2001. Although we were litigated to develop a timeframe for moving forward on the review of candidate species, the Act requires us to promptly make our evaluations for species considered candidates. Any settlements reached as a result of litigation took into consideration what was best for conservation and protection of candidate or sensitive species and were not dictated by litigants.
(46) Comment: The Texas Comptroller of Public Accounts stated that they were concerned that listing of the western yellow-billed cuckoo would have potential economic impacts on landowners, businesses, and communities within the boundary of the DPS in
Our Response: See our response to Comment 45 above for economic considerations in the listing process and our view on the information used to determine the status of the species. In regard to conservation measures for the southwestern willow flycatcher being adequate to conserve the western yellow-billed cuckoo, we disagree. Although the range of the southwestern willow flycatcher and the western yellow-billed cuckoo overlap to some degree and they are found in similar habitats, that is not always the case and the two species have very different habitat and ecological requirements.
Comments on "Endangered" vs. "Threatened" Status
(47) Comment: More than 12,000 commenters stated that the western yellow-billed cuckoo should be listed as "endangered" rather than the proposed "threatened" status.
Our Response: The Act defines an endangered species as any species that is currently "in danger of extinction throughout all or a significant portion of its range" and a threatened species as any species "that is likely to become endangered throughout all or a significant portion of its range within the foreseeable future." Based on the available information on the range and distribution of the species, the immediacy and severity of threats facing the species, the persistence of the species throughout most of its historical range, and the rate of decline of the species, we have determined that the western yellow-billed cuckoo meets the definition of a threatened species rather than an endangered species under the Act. See the Determination section below for additional discussion of our rationale for a "threatened" determination.
(48) Comment: One commenter stated that the entire species (both in the eastern and western
Our Response: Our analysis in the rule is limited to the petitioned entity (western
Comments on the Distinct Population Segment
(49) Comment: One commenter stated that the western DPS of the yellow-billed cuckoo also meets significance because of persistence of population on unusual or unique ecological setting (i.e., streamside riparian areas in arid West).
Our Response: We appreciate this additional information and have considered this in our listing determination. Yellow-billed cuckoos in both the East and West nest in riparian habitat. The species in the eastern
(50) Comment: Several commenters stated that there had been too many studies on the yellow-billed cuckoo and other commenters stated that there had been too few studies. Genetics and taxonomic uniqueness was a suggested area of study by one commenter.
Our Response: Although there has been much focus on research on the yellow-billed cuckoo, most of these efforts have been on survey and monitoring. Additional research activity is a common response once a species is identified for listing under the Act. However, other information, such as migratory routes, timing, and wintering ground use, has been scarce, and we agree that there are many areas of the life history, ecology, genetics, and taxonomy of the western yellow-billed cuckoo that need further research. However, in making our listing determination, we must use the best scientific and commercial data available in coming to any conclusions on whether the species should be listed.
(51) Comment: One commenter stated that the eastern and western yellow-billed cuckoos may be interbreeding on the wintering grounds.
Our Response: Because yellow-billed cuckoos do not breed on their wintering grounds in
(52) Comment: Several commenters do not believe that differences in migration timing between eastern and western yellow-billed cuckoos are evidence that there is a marked separation between the two groups.
Our Response: The proposed rule and this final rule identify a wide variety of factors that separates western yellow-billed cuckoos from the rest of the taxon. Migration timing is one of these factors. In general, migration timing is governed by forces of natural selection that operate over long periods of time. Given that populations of eastern and western yellow-billed cuckoos arrive on their breeding grounds, at the same latitude, a month or more apart is significant and is most likely governed by evolutionary forces. This pattern of consistently arriving on their respective breeding grounds a month or more apart is different from year to year, and variations in weather may lead to individual birds arriving on the breeding grounds a few days earlier or later than normal. Please see the Distinct Vertebrate Population Segment Analysis section, above, for further explanation of our rationale for determining that the western yellow-billed cuckoo is a valid DPS.
(53) Comment: Three commenters stated that they believed that the species was not distinct.
Our Response: The Service is listing a DPS rather than a species or subspecies. As detailed in the Taxonomy section under Background and Discreteness section of the Distinct Vertebrate Population Segment Analysis above, the western DPS of the yellow-billed cuckoo coincides with the range of the proposed subspecies boundary of the "western" yellow-billed cuckoo (Coccyzus americanus occidentalis). However, because there is some scientific uncertainty to the validity of the subspecies, the Service is not listing the subspecies, but rather is listing the western DPS.
(54) Comment: Twelve commenters stated that there have been recent declines of breeding populations of western yellow-billed cuckoos in various locations of
Our Response: These additional observations support the information that we presented in the proposed and this final listing rule regarding population trends for the species in these States.
(55) Comment: Nine commenters stated that the western yellow-billed cuckoo was not threatened, that they were either not declining or not declining at a rate that would lead to extinction, and that yellow-billed cuckoos were doing well in the East.
Our Response: Yellow-billed cuckoos in the East are declining at 1.4 to 1.6 percent per year over the past 43 years (Sauer et al. 2012, entire). Based on the best available science and data, western yellow-billed cuckoos have declined dramatically throughout their range over the past 150 years. This decline has continued in recent years, and with very few exceptions (e.g., the
(56) Comment: Eight comments were received on data analysis and proposed rule preparation. Issues raised included the lack of a population viability analysis, the lack of a global population analysis, inadequate citations support for statements made in the document, not providing the names of Service biologists who reviewed data, taking a
Our Response: Current available scientific data on the western yellow-billed cuckoo are not sufficient to conduct a meaningful population viability analysis. Too many of the important parameters are not known well enough for the results to be reliable. The State-by-State and region-by-region analysis of the entire range of the western DPS of the yellow-billed cuckoo is essentially a global population analysis. Every attempt has been made to be certain that citations support the statements made in the proposed and this final rule. Where we do not have specific reference support we explained our rationale based on the best available information on coming to any conclusions. It is not Service policy to list names of document authors or those who reviewed data. Much of the research that has been conducted on the western yellow-billed cuckoos has occurred in
(57) Comment: Several commenters stated that western yellow-billed cuckoo survey data were missing from the proposed rule or the data have been updated after the proposed rule was published (e.g.,
Our Response: We have considered this updated information in our final listing determination, and the information will be considered in the final critical habitat designation and future recovery plan.
(58) Comment: One commenter asked why western yellow-billed cuckoos are continuing to decline with all the habitat protection that has been happening over the past 25 years.
Our Response: It is true that significant habitat protection and restoration has been underway for the past 25 to 30 years. Much of this work has been done on a project-by-project basis or on a smaller scale than will likely be necessary for the stabilization and recovery of the species. Recovery goals for western yellow-billed cuckoos and their habitat will be set in the recovery plan for the species as it is developed. In some areas, such as the Sacramento River, western yellow-billed cuckoo populations have continued to decline even though significant habitat restoration activities have been carried out. Aging of the existing habitat and increased occupancy by invasive species, especially edible fig (Ficus carica) and black walnut (Juglans sp.), may be contributing factors. In addition, effects of pesticides on caterpillars may be a factor in many areas. It is indeed a concern that western yellow-billed cuckoos have declined even in areas where habitat has been protected and has either been stabilized or has increased. Further research is needed to determine the exact causes of this continued decline.
(59) Comment: One commenter questioned our science and asked that all information on western yellow-billed cuckoo populations and declines should be removed from the discussion in the rule.
Our Response: The information on western yellow-billed cuckoo population and declines presented in the proposed and this final rule is based on the best available science. In making listing determinations under the Act, we must conduct a five-factor analysis on the threats facing a species based on the best available scientific and commercial information. In some cases the information on a species' status and trends is unclear or the information available is sparse. In these cases, we nonetheless must base our determinations on the best available information. In the case of the western yellow-billed cuckoo, the available information on population status and declines is appropriate to include in our discussion of the status of the species and in making our final determination on the species' listing status of threatened.
(60) Comment: Numerous commenters have concerns regarding survey methods, comparison of survey data, accuracy of survey counts, and changes in survey protocols over the years for the yellow-billed cuckoo.</p>
Our Response: Please see response to Comment 5 above for our response to concerns over the survey protocols and other survey concerns.
(61) Comment: Several commenters indicated that habitat use separates eastern and western yellow-billed cuckoo populations. One commenter further stated that in eastern
Our Response: We appreciate this additional information and have considered this in our listing determination. Additional research on this topic would be valuable. The information provided will also be considered further in recovery planning. See response to Comment 6, above, for additional information.
(62) Comment: One commenter stated that yellow-billed cuckoos select much different habitat in the East than they do in the West.
Our Response: We appreciate this additional information and have considered this in our listing determination. We recognize that habitat use is different between eastern and western populations of yellow-billed cuckoos. See our response to Comment 6, above, for additional discussion on habitat use in the eastern and western
(63) Comment: One commenter stated that understory vegetation was as important to western yellow-billed cuckoos as overstory vegetation.
Our Response: As stated in the proposed listing rule and cited by reference in this final rule, the amount, size, composition, and density of habitat are important habitat selection criteria for the western yellow-billed cuckoo. Although habitat characteristics vary across the range of the species, understory vegetation is an important characteristic for the species. For example, along the Sacramento River, the size of the site, the amount of riparian habitat in each 5-mi (8-km) river segment, and the presence of young woody vegetation (understory) were the most important factors in a model explaining the distribution of yellow-billed cuckoo pairs (Halterman 1991, p. 30). Along the lower
(64) Comment: Two commenters stated that western yellow-billed cuckoos do not need large blocks of riparian habitat, and one commenter stated that they do not need riparian habitat at all. Another commenter stated that habitat use and patch size needed were not well-defined.
Our Response: The use of large blocks of riparian habitat for yellow-billed cuckoos in western
(65) Comment: Eight commenters stated that yellow-billed cuckoos were providing ecosystem services by eating caterpillars.
Our Response: We appreciate this additional information and have considered this in our listing determination. Yellow-billed cuckoos in eastern
Comments on Specific Habitat Areas
(66) Comment: Two commenters stated that water transfers from agriculture to urban areas and from the
Our Response: We appreciate this additional information and have considered this in our listing determination. We have identified the disruption of "natural" stream hydrology and flows as a threat to the species. The occupied habitat for the western yellow-billed cuckoo in the
(67) Comment: One commenter stated that western yellow-billed cuckoo habitat was declining along the
Our Response: We appreciate this additional information and have considered this in our listing determination. This is consistent with the pattern of habitat loss and degradation described in the Factor A section of this document.
(68) Comment: Several commenters pointed out the importance of the
Our Response: We appreciate this additional information and have considered this in our listing determination.
(69) Comment: Commenters in
(70) Comment: One commenter mentioned that land in
Our Response: We appreciate the commenter's statement, but they did not provide specific information on the subject. Our research on agricultural land use changes for
(71) Comment: One commenter stated that recent information shows that yellow-billed cuckoos that breed in the eastern
Our Response: Researchers (Rowher and Wood 2013 pp. 243-250) have recently retracted an earlier assertion that yellow-billed cuckoos bred in eastern
Comments on Factors Affecting the Species
(72) Comment: Three commenters addressed the threat of proposed mining operations in the
Our Response: We concur that gravel mining and other mining activity can impact the western yellow-billed cuckoo and its habitat. This is a localized threat that is discussed under Factor A section of the final rule. See Factor A. The Present or Threatened Destruction, Modification, or Curtailment of its Habitat or Range, for additional discussion on the threat of mining.
(73) Comment: One commenter indicated that impacts to livestock ranchers are unequal east and west of the DPS line, making for unfair economic competition.
Our Response: According to the Act, we are to make listing determinations solely on the basis of the best scientific and commercial data available. The economic impact of listing is only considered when designating critical habitat for a listed species. We will consider the incremental impacts on livestock grazing operations during our designation of critical habitat for the species.
(74) Comment: One commenter stated that livestock grazing improves the ecological condition of riparian systems, while another stated that in the past cattle grazing was destructive, but that it was no longer a problem in riparian habitats.
Our Response: We identified past and current grazing activity in riparian areas occupied by the species to be a threat to the western yellow-billed cuckoo. We are not aware of any science or data that support the statement that livestock grazing improves the ecological condition of riparian systems. The western yellow-billed cuckoo nesting habitat is structurally complex with tall trees, a multistoried vegetative understory, low woody vegetation (Halterman 1991, p. 35), and higher shrub area than sites without western yellow-billed cuckoos (
Controlled and seasonal livestock grazing can occur in a manner that is compatible with the management of western yellow-billed cuckoo habitat, although effective monitoring and management would most likely be needed especially in the more arid regions of the Southwest. Current grazing management practices are less harmful to riparian systems than some past practices. However, especially during droughts, riparian zones can still be grazed in a manner that may degrade riparian habitat attributes and prevent long-term health and persistence of these systems.
(75) Comment: One commenter stated that just because
Our Response: Listing determinations are based on habitat and population trends and threats. A severe threat in one portion of the range can lead to listing throughout the range. However, for the western yellow-billed cuckoo, there is abundant evidence that riparian habitat has been lost throughout the range of the species. This loss is greater in some areas than in others, but the threats to the western yellow-billed cuckoo through habitat loss, as detailed in this final rule, are widespread and not limited to
(76) Comment: Three commenters stated that the proposed rule does not show a causal link between habitat loss and population declines.
Our Response: We disagree. The data and information utilized for the proposed and final rules show a strong link between the declines in the western DPS of the yellow-billed cuckoo and riparian habitat. The Historical and Current Status section of the proposed rule, which is incorporated (by reference) into this final rule, lists numerous examples where riparian forests were removed and the western yellow-billed cuckoo population declined. In addition, literature is referenced in the rule that provides abundant additional supporting examples connecting loss of habitat to western yellow-billed cuckoo population declines. Factor A under the Summary of Factors Affecting the Species section in this final rule details the threats to riparian habitat both in the past and present.
(77) Comment: Three commenters said that riparian habitat may have declined by 90 percent in the past, but that it now is increasing. One commenter said that there is no evidence that habitat is being adversely affected by natural or manmade factors.
Our Response: Riparian habitat is increasing in some areas, but at the same time is decreasing or becoming less suitable in other areas. The overall trend throughout the range of the western yellow-billed cuckoo is not known. Simply measuring the extent of riparian habitat from one time period to the next will not tell what the effect on western yellow-billed cuckoos will be. Tens of thousands of acres of riparian habitat still exist on the
(78) Comment: One commenter asked that all statements regarding threats from water projects and water management should be removed from the document.
Our Response: Threats from water projects and water management are significant threats as detailed in the proposed and this final rule. As such, discussion of these threats is appropriate. See discussion under the
(79) Comment: One commenter stated that western yellow-billed cuckoos had declined because of the drought and will recover now that the rains have returned.
Our Response: While drought may have a negative effect on western yellow-billed cuckoo populations, the declines in the western yellow-billed cuckoo's range and populations have occurred through both wet and dry periods over the past 150 years.
Pesticides and Disease
(80) Comment: One commenter stated that dichlorodiphenyltrichloroethane (DDT) does not thin eggshells and that western yellow-billed cuckoo eggshells in the West are thicker because there is more calcium in the West.
Our Response: There is a large body of literature linking environmental DDT and its derivatives (e.g., dichlorodiphenyldichloroethylene (DDE)) to eggshell thinning in birds. Calcium deficiency can cause eggshell thinning in bird eggs, but this effect has not been demonstrated through region-by-region comparisons or a population-to-population comparisons. Trees and shrubs rarely show the effects of calcium deficiency within either the eastern or western range of the yellow-billed cuckoo in
(81) Comment: One commenter stated that rotenone used by Game and Fish agencies to kill fish may have injured western yellow-billed cuckoos.
Our Response: Although rotenone is classified as a broad-spectrum pesticide and has been used to control insects, we are not aware of any information that the use of the chemical as a piscicide (control of fish) has harmed the western yellow-billed cuckoo. The exposure risk of rotenone to terrestrial birds is low, and studies have shown that it would take levels of consumption of fish, vegetation, and/or water that are not physically possible or probable to reach a lethal dose (Finlayson et al. 2000, p. 193). The commenter did not provide information on the possible mechanism behind this perceived threat.
(82) Comment: One commenter stated that West Nile virus was a reason that yellow-billed cuckoos have declined.
Our Response: As discussed below in the Disease or Predation section, the
(83) Comment: One commenter stated that most pesticides are used in highly populated areas by people who do not follow label instructions.
Our Response: While this statement may be true, western yellow-billed cuckoos rarely occur in or near highly populated areas and are much more likely to be affected by application of pesticides on adjacent agricultural fields. See "Pesticides" section, below, for further information on the impacts of pesticides on the western yellow-billed cuckoo.
(84) Comment: Two commenters mentioned, and included references on, the new threat of neonicotinoid pesticides, which are extremely toxic to caterpillars.
Our Response: Neonicotinoid pesticides are systemic chemicals that are taken up through various plant parts and can be distributed through a plant's tissues. These chemicals can be applied to a plant as a seed coating, through soil contact, through irrigation water, or as a foliar spray. Many of these chemicals are long-acting, with half-lives up to 2 years. Plant tissues that have been treated are toxic to both sap-sucking (e.g., aphids and true bugs) and foliage-eating insects (e.g., caterpillars, katydids, grasshoppers, and beetles). Many of these foliage-eating insects are potential prey of the western yellow-billed cuckoo. This information has been incorporated into this final rule.
(85) Comment: Several commenters stated that there were threats to western yellow-billed cuckoos that were not discussed in the proposed rule. These included threats from recreational shooting, threats from solar generation sites, and threats from wind power.
Our Response: All the activities may impact the western yellow-billed cuckoo. In our evaluation of threats, we identified those threats that rise to the level of being a threat to the continued existence of the species. Although these activities affect the species, we do not find that these activities would have a significant effect on the species.
Comment on Regulatory Mechanisms
(86) Comment: Five commenters stated that Factor D, inadequacy of existing regulatory mechanisms, is also a significant threat. Other commenters stated that the proposed rule ignored the Federal regulatory mechanisms that protect western yellow-billed cuckoos and their habitat.
Our Response: The proposed and this final rule present a detailed discussion of Federal, State, and international laws and regulations that provide some protection and conservation benefit to the western DPS of the yellow-billed cuckoo. The western yellow-billed cuckoo has continued to decline, and its habitat has continued to be lost and degraded. In determining if a species is to be added to the List of Endangered or Threatened Wildlife, the species needs only to be threatened by one of the five factors listed in section 4(a)(1) of the Act. According to our analysis of the best scientific and commercial information available, the western yellow-billed cuckoo is threatened by both Factors A and E. Our evaluation of Factor D discusses the extent to which the inadequacy of each existing regulatory mechanism exacerbates the threats evaluated in Factors A and E. An individual regulatory mechanism may reduce a threat to a greater or lesser extent, but none separately or in combination reduces any of the threats to the point that they are no longer threats to the western yellow-billed cuckoo.
Comment on Cumulative Effects
(87) Comment: Several commenters stated that the proposed rule needs more emphasis on cumulative effects.
Our Response: We recognize that cumulative effects are important. Cumulative effects are discussed in several sections of the proposed and this final rule, including the section of water management, grazing, climate change, and pesticide use. Please see those sections for additional information on the impacts of cumulative effects on the western yellow-billed cuckoo.
Comment on Conservation Measures
(88) Comment: Eighteen commenters discussed conservation measures and indicated that benefits from conservation measures were not discussed and that conservation measures for other species should "take care" of the western yellow-billed cuckoo. Others stated that there was a need to quantify the benefits of riparian habitat restoration to western yellow-billed cuckoos.
Our Response: Conservation measures and their effect on western yellow-billed cuckoos are discussed in the proposed and this final rule. The majority of currently implemented conservation measures focus on species other than the western yellow-billed cuckoo. Conservation measures that are carried out for other species may have a positive effect on the western yellow-billed cuckoo, but western yellow-billed cuckoos, while being a riparian obligate species, have different ecological requirements than other species that are already listed (e.g., southwestern willow flycatcher and least Bell's vireo). As a result, it has not been proven that the conservation measures outlined by commenters would "take care" of the western yellow-billed cuckoo and its habitat. In regards to quantification of the benefits habitat restoration, we readily acknowledge that any well-developed and maintained restoration efforts will most likely benefit the western yellow-billed cuckoo and its habitat. However, we have found that, in some cases, even when habitat restoration has been completed, the benefit to the species has not been clear, as some areas still remain unoccupied or their numbers continue to decline.
(89) Comment: Two commenters were concerned that the listing of the western yellow-billed cuckoo would disrupt recovery efforts for the southwestern willow flycatcher and the Rio Grande silvery minnow (Hybognathus amarus).
Our Response: We disagree. Although additional coordination would be required to ensure that the habitat and species needs for all three species was occurring for a potential recovery action, we do not believe that that process would favor or harm any one single species in particular. In fact, by implementing recovery efforts for two or more species it would present opportunities that may be larger in scale or allow greater flexibility than smaller disjointed efforts for single species conservation.
Comments on Potential Exemptions (Section 4(d) Rule)
(90) Comment: Several commenters requested that rules under section 4(d) of the Act be included in the listing to exempt the following activities: (a) Oil and gas development and other economic activities; (b) riparian restoration activities; (c) all existing conservation activities; and (d) land and water use activities.
Our Response: Section 4(d) of the Act allows the Secretary the discretion to issue such regulations as [s]he deems necessary and advisable to provide for the conservation of a species. The Service's standard policy (under 50 CFR 17.31(a)) for issuing prohibitions for threatened species is to apply all the prohibitions applicable to endangered species to a threatened species unless otherwise revoked by issuance of more specific prohibitions. In the case of the western yellow-billed cuckoo, we reviewed whether the "standard" prohibitions apply or whether more specific prohibitions might be appropriate for the western yellow-billed cuckoo. Based on our review, we have determined that modifying our "standard" regulations for a threatened species would not be necessary and advisable in providing for the conservation of the western yellow-billed cuckoo. If new or additional information is received that may suggest that a rule issued under section 4(d) of the Act may be appropriate, we would review such information and, if appropriate, issue a proposed section 4(d) rule for public comment prior to developing any final section 4(d) prohibitions for the species.
Listing Process Public Input
(91) Comment: Eight comments were received on the listing process. This included statements regarding: Inadequate public feedback, that listing decisions should reflect customs and cultures of the local community, that court settlements should not be a factor in listing decisions, and that a finding of warranted but precluded should have been maintained as a possibility.
Our Response: In accordance with the Act and the Administrative Procedure Act (5 U.S.C. Subchapter II), and our regulations in Title 50 of the Code of Federal Regulations (CFR), we have solicited public comment on our proposed listing action. The comment period was reopened twice to insure that the public had ample opportunity to comment on the proposed rule. Listing endangered or threatened species is a process that examines threats to the species. Although customs and cultures of local communities are important considerations, they are not part of the listing process under the Act. Court settlements were not a factor in preparation of the proposed rule to list the western DPS of the yellow-billed cuckoo as a threatened species. The court settlement simply guaranteed that the Service would do an analysis of the western DPS of the yellow-billed cuckoo and determine if it should be listed as an endangered species or a threatened species or not listed. Regarding maintaining the warranted-but-precluded category as a listing possibility, the western yellow-billed cuckoo was previously found to be "warranted but precluded," in 2001; the next step in the listing process is to either propose it for listing (and finalize the proposal if appropriate) or make a finding that the species is no longer warranted for listing.
Use of the Best Available Scientific and Commercial Information
(92) Comment: Ten commenters said that the science used in the proposed rule is flawed, inaccurate, and biased and is not the best available science. Several commenters indicated that the Service should only select the "best" data from the data that was available.
Our Response: All available sources of data on distribution and abundance of yellow-billed cuckoos in the western
(93) Comment: One commenter stated that the Service did not cite papers in the proposed rule that were cited in the 12-month finding.
Our Response: The proposed rule is an updated and more thorough review of the best available information on the western yellow-billed cuckoo and is an independent document from the 12-month finding (66 FR 38611;
(94) Comment: One commenter said that two recent peer reviewed papers (Villarreal et al. 2014 and Wallace et al. 2013) that were not cited in the proposed rule are not valid.
Our Response: The Service appreciates the commenter drawing our attention to these papers that had published after the proposed rule was published in the
(95) Comment: One commenter stated that they did not like the use of data from the Arizona Breeding Bird Atlas (Corman and Wise-
Our Response: Arizona Breeding Bird Atlas data (Corman and Wise-
(96) Comment: Two commenters stated that listing the western yellow-billed cuckoo will restrict property rights and access to public lands.
Our Response: This comment was presented generally with no specific instances or information. It is very unlikely that listing the western yellow-billed cuckoo will have the effect of limiting access to public lands. Direct human disturbance is not seen as a major threat to the western yellow-billed cuckoo as discussed in the final rule. It is unclear what the commenter meant by restriction of property rights, but it is not likely that listing the western yellow-billed cuckoo will have an adverse effect on private property ownership or use.
Summary of Changes From Proposed Rule
Based upon our review of the public comments, comments from other Federal and State agencies, peer review comments, and any new relevant information that may have become available since the publication of the proposal, we reevaluated our proposed rule and made changes as appropriate. Other than minor clarifications and incorporation of additional information on the species' biology, this final rule has not changed significantly from the proposed rule. Changes to the final rule include: (1) Updates to the life-history information of the species' vocalizations and how these changes may have affected survey results for the species; (2) updates to survey data (though no new populations have been located and no major increases have been noted in the past 2 years); (3) updates to the threats in Factor A; and (4) the addition of threats of neonicotinoid pesticides in Factor E.
We did receive information from the
Summary of Factors Affecting the Species
Section 4 of the Act and its implementing regulations (50 CFR 424) set forth the procedures for adding species to the Federal Lists of Endangered and Threatened Wildlife and Plants. A species may be determined to be an endangered or threatened species due to one or more of the five factors described in section 4(a)(1) of the Act: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; or (E) other natural or manmade factors affecting its continued existence. Listing actions may be warranted based on any of the above threat factors, singly or in combination. Each of these factors is discussed below.
A. The Present or Threatened Destruction, Modification, or Curtailment of Its Habitat or Range
The decline of the western yellow-billed cuckoo is primarily the result of riparian habitat loss and degradation. Within the three States with the highest historical number of western yellow-billed cuckoo pairs, past riparian habitat losses are estimated to be about 90 to 95 percent in
Moreover, these impacts are often subtle. As described in the
Past actions by humans have resulted in changes to the landscape, the hydrology, or both such that they prevent the riparian plants that are the basis of the species' habitat from growing at all. The consequences of these past actions may have initially resulted in destruction or modification of then-existing riparian habitat; however, once that habitat is lost, the changed conditions (such as changed hydrologic regime) also prevents riparian habitat from regenerating, even in the absence of other impacts. For example, channelization--through manmade levees or other constructs, or through channel incising as a consequence of other actions--may leave the geographical area where riparian plants once grew (such as the watercourse's floodplain) physically untouched, but the altered hydrology prevents riparian plant species from germinating and growing.
Principal causes of riparian habitat destruction, modification, and degradation in the range of the western yellow-billed cuckoo have occurred from alteration of hydrology due to dams, water diversions, management of riverflow that differs from natural hydrological patterns, channelization, and levees and other forms of bank stabilization that encroach into the floodplain. These losses are further exacerbated by conversion of floodplains for agricultural uses, such as crops and livestock grazing. In combination with altered hydrology, these threats promote the conversion of existing primarily native habitats to monotypic stands of nonnative vegetation, which reduce the suitability of riparian habitat for the western yellow-billed cuckoo. Other threats to riparian habitat include long-term drought and climate change. These threats are summarized in a recent detailed review of the literature on the subject (Poff et al. 2011, pp. 1241-1254). Water management and delivery throughout the western <location value="LC/us" idsrc="xmltag.org">United States is contentious, and resolving issues related to water allocation is difficult and often a lengthy, heavily contested process. The exact timeframe for resolving water management and delivery issues and their impact on the western yellow-billed cuckoo and its habitat would vary on the location, resource demands, sensitive habitat or species concerns, stakeholders, and amount of water available. As a result, we would expect that resolving water issues for the various uses (agriculture, urbanization, wildlife, and tribal interests) in the west will be a lengthy ongoing process and not be resolved in the near future (10-20 years) and may take substantially longer considering the increased demands and the effects of climate change. The Factor A threats are described in more detail below. Moreover, past and ongoing impacts to the species' habitat are working in combination with other threats, which are discussed in greater detail in Factors C and E, below.
Habitat Loss From Dams and Alteration of Hydrology Dams
Several researchers and scientific organizations including the Service reviewed the following effects of human modification of natural hydrological processes on riparian habitat, including those from dams (Poff et al. 1997, pp. 769-784; Greco 1999, pp. 36-38;
Dam construction has been occurring since the settlement of western
There are now dozens of large dams and scores of smaller dams on rivers throughout the range of the western yellow-billed cuckoo. Today, the rate of building new dams has slowed because most of the highest quality dam sites already have dams constructed on them. There were proposals to build two dams on
While the amount of habitat lost within the construction zone of a dam is relatively small, far greater amounts of habitat are destroyed in the areas of inundation and through the ongoing effects of the amount and timing of water releases through the dam operation, which affects both upstream and downstream habitats. Ongoing downstream effects to riparian habitat from dams include changes in sediment transport due to sediment retention behind the dams so that channels below a dam become increasingly "sediment starved." This situation causes vertical erosion (downcutting), which can lead to loss of river terraces that sustain riparian vegetation (NAS 2002, pp. 145-150; Poff et al. 2009, pp. 773-774; Poff and Zimmerman 2010, pp. 196-197).
Ongoing operations of large dams can also dampen the magnitude of normal high flows, thus preventing cottonwood germination (
In the case of the
After the completion of the larger dams on the
While alteration of hydrology due to dam construction and other water supply projects has been widely implicated in the loss and degradation of downstream riparian habitat for the western yellow-billed cuckoo (
The threat to the western yellow-billed cuckoo's habitat from fluctuating water levels behind dams is likely to occur elsewhere in the range of the western yellow-billed cuckoo. In
The temporary gain in riparian habitat at the inflow of reservoirs can be beneficial to the western yellow-billed cuckoo by providing large expanses of additional nesting and foraging habitat during a sequence of low-water years. However, the value of such habitat is affected by fluctuating water levels between years. Drastically fluctuating water levels with alternating inundation and desiccation cycles have been associated with fluctuations in populations of western yellow-billed cuckoos that breed in reservoir inflow sites (Laymon and Williams 2002, pp. 12-13; Henneman 2008, pp. 12-13). For example, along the
The water level continues to remain below capacity at
Lake Isabella is currently managed to minimize incidental take of the southwestern willow flycatcher (flycatcher) (Empidonax traillii extimus) from reservoir operations and recreation using reasonable and prudent measures developed during consultation with the Service (Service 1996, 1999, and 2005, entire). Some of these measures to conserve the flycatcher may be beneficial to the western yellow-billed cuckoo; however, the eventual inundation of the drawdown area of the reservoir will result in some degree of temporary habitat loss and degradation under current operational guidelines and may result in permanent loss of habitat for the western yellow-billed cuckoo if the proposed dam raise is implemented. Similar periods of inundation and drawdown, resulting in corresponding development and destruction of suitable western yellow-billed cuckoo habitat, occur at
In Arizona, following the high water levels of 1983-1984 and 1986 on the
In Sonora, Mexico, large dams exist on the Mayo,
Despite some positive effects of dams on increasing western yellow-billed cuckoo habitat in a few areas, these gains in habitat are only temporary, and overall, the net effect of dams on the species has been negative. As such, dams and their ongoing operations are a threat to the western yellow-billed cuckoo over most of its range. This threat has resulted in substantial historical losses of western yellow-billed cuckoo habitat resulting in a curtailment of the species' range. The ongoing operation of these dams is likely to have minor impacts to the species at any given location, but because so many of the waterways within the range of the species have been dammed, we believe this threat has a substantial cumulative impact on the habitat of the western yellow-billed cuckoo, especially when considered with other threats. Moreover, we expect the operation of these dams will continue in a similar manner for decades to come, and thus we expect this threat to be an ongoing impact to the western yellow-billed cuckoo's habitat.
The areas where the floodplain is still hydrologically connected to the river and has relatively unconstrained riverflow, such as in some areas of
The river provides habitat characteristics that Laymon (1998, p. 4) indicated were important for the western yellow-billed cuckoo in
We conclude that dams continue to affect both the downstream and upstream habitat through alteration of flows. These effects can include widely fluctuating water levels at inflow sites that inundate nesting habitat, limit food resources, and flood or desiccate habitat (Poff et al. 1997, pp. 769-784; Greco 1999, pp. 36-38; NAS 2002, pp. 145-150; Service 2002, Appendix I, pp. 1-12). Downstream effects caused by sediment retention behind dams, or sediment scouring and removal caused by excessive water releases, do not mimic the natural flow regimes and often result in the inability for cottonwoods to become established or regenerate and provide habitat for the western yellow-billed cuckoo. Woody and herbaceous debris accumulates in the absence of these scouring flows, increasing fire risk and intensity (Stromberg and Chew 2002, pp. 195-219) (see section on Wildfire below).
Dams and their flow modifications have ongoing effects to habitat and will likely do so for decades to come, further modifying the habitat of the western yellow-billed cuckoo. Therefore, direct and indirect destruction of riparian habitat resulting from altered hydrology from past dam-building activities continues to contribute to the curtailment of the range of the western yellow-billed cuckoo. Additionally, as a result of future predicted climate change (see Climate Change section below), the climate within the range of the western yellow-billed cuckoo will likely become drier, which will increase the demand for water storage and conveyance systems, which in turn will likely increase the frequency and severity of impacts on western yellow-billed cuckoo habitat (Stromberg et al. 2013, pp. 411-415).
Surface and Ground Water Diversion
Water extractions, both from surface water diversions and ground water pumping, can negatively affect riparian vegetation (Poff et al. 1997, pp. 769-784; Service 2002, Appendix I, pp. 1-8). Water diversions and withdrawals can lower ground water levels in the vicinity of riparian vegetation. Because ground water and surface water are generally connected in floodplains, lowering ground water levels by only about 3 ft (1 m) beneath riparian areas is sometimes sufficient to induce water stress in riparian trees, especially in the western
Adverse effects of excessive ground water extraction on riparian vegetation have been well-documented in the southwestern
The hydrologic regime (stream flow pattern) and supply of (and interaction between) surface and subsurface water is a driving factor in the long-term maintenance, growth, recycling, and regeneration of western yellow-billed cuckoo habitat (Service 2002, p. 16). As streams reach the lowlands, their gradients typically flatten and surrounding terrain opens into broader floodplains (Service 2002, p. 32). In these geographic settings, the stream-flow patterns (frequency, magnitude, duration, and timing) will provide the necessary stream-channel conditions (wide configuration, high sediment deposition, periodic inundation, recharged aquifers, lateral channel movement, and elevated ground-water tables throughout the floodplain) that result in the development of riparian habitat suitable for use by western yellow-billed cuckoos (Poff et al. 1997, pp. 770-772; Service 2002, p. 16).
Allowing the river to flow over the width of the floodplain, when overbank flooding occurs, is integral to allow deposition of fine moist soils, water, nutrients, and seeds that provide the essential material for plant germination and growth. An abundance and distribution of fine sediments extending farther laterally across the floodplain and deeper underneath the surface retains much more subsurface water, which in turn supplies water for the development of the vegetation that provides western yellow-billed cuckoo habitat and microhabitat conditions (Service 2002, p. 16). The interconnected interaction between ground water and surface water contributes to the quality of the riparian vegetation community (structure and plant species) and will influence the ability of vegetation to germinate, regenerate, and maintain its foliage density, vigor, and species composition (
In many instances, western yellow-billed cuckoo breeding site occur along streams where human impacts are minimized enough to allow more natural processes to create and maintain the habitat. However, there are also breeding sites that are supported by various types of supplemental water including agricultural and urban runoff, treated water outflow, irrigation or diversion ditches, reservoirs, and dam outflows (Service 2002, p. D-15). Although the waters provided to these habitats might be considered "artificial," they are often important for maintaining the habitat in appropriate condition for breeding western yellow-billed cuckoos within the existing environment.
Encroachment of Levees and Flood Control and Bank Stabilization Structures Into the River Channel and Floodplain
Other alterations in river hydrology with ongoing effects on western yellow-billed cuckoo habitat include river channelization, construction of levees, bank stabilization, and placement of any flood control structures that encroach into the river and its floodplain. These actions result in direct loss of habitat from construction and from maintenance activities that remove woody vegetation that has become established on the structures. Furthermore, these structures are effective, by design, at severing the hydrologic connection of the river's main channel and the river's immediate floodplain, thereby preventing overbank flooding. By preventing overbank flooding, levees and other similar structures reduce the amount of water available to riparian vegetation in the floodplain, which results in desiccation and eventual loss and degradation of riparian habitat (Vogl 1980, pp. 84-86; NAS 2002, p. 155; Greco 2012, pp. 8-9). Such effects are less destructive, however, for those levees located farther from the stream system, such as those outside the meander belt of a river (Greco 2012, p. 4).
As an illustrative example, we provide a brief summary of how river channelization, construction of levees close to the river, and rock riprap armoring along the levees have caused destruction and modification of western yellow-billed cuckoo habitat on the Sacramento River, one of the most substantial historical nesting and foraging habitat areas for the western yellow-billed cuckoo.
Channelizing the river and severing the connection to the floodplain has severely altered the natural disturbance regime that would have allowed riparian habitat to regenerate now and in the future (Poff et al. 1997, pp. 769-784; Greco 2008, p. 6; Greco 2012, pp. 8-9). The result is that much of the river's remaining riparian habitat is modified, and now occurs in narrow, disconnected, linear strips (Service 2000, pp. 26-29; Halterman et al. 2001, p. 4) that are not utilized by the western yellow-billed cuckoo for breeding (
An additional pervasive threat is the design of open-channel flood control channels with inappropriately smooth roughness coefficients. This creation over-scours the floodplains and requires removal of woody riparian vegetation that regenerates on floodplains, which in turn leads to floodplains with no western yellow-billed cuckoo habitat (Greco 2013, pp. 707-717).
Similarly, transportation systems have directly and indirectly altered a large number of riparian areas in western
Other past and ongoing effects to riparian habitat result from gravel mining (Kondolf et al. 2001, pp. 54, 59). Extraction of gravel, primarily for construction products, typically occurs along rivers and adjacent floodplains where gravel deposits are naturally found. Large amounts of gravel removal from the stream and active floodplain result in channel downcutting or incision, which affects groundwater levels, frequency of overbank flows, bank stability, and the extent and character of riparian vegetation of specific stream reaches (
Furthermore, gravel extraction creates a knickpoint (a sharp change in channel slope) that typically erodes upstream in a process known as headcutting, which has the potential to propagate upstream for miles on the main river and its tributaries. As headcuts migrate upstream, the incision propagates upstream (Kondolf et al. 2001, p. 49). This process creates ongoing and future impacts to habitat from past as well as current gravel mining operations. Similar to the effects of manmade levees when they disconnect floodplain habitat from the active river channel, artificial channel incision as a result of gravel mining and similar activities reduces overbank flooding. This situation reduces the hydrological connection to the floodplain (Kondolf et al. 2001, p. 56), thereby resulting in subsequent loss and degradation of riparian habitat for the western yellow-billed cuckoo, throughout its range, including
In conclusion, dams, channelization, and other manmade features that alter the watercourse hydrology and encroach into the active channel and floodplain are threats to the habitat of the western yellow-billed cuckoo because they, separately or in combination, significantly reduce and degrade nesting and foraging habitats. The natural processes that sustain riparian habitat in these and similar dammed and channelized river systems in the American West and in northwestern
Following the effects from alterations in hydrology in severity, conversion of riparian areas for agricultural crops and livestock grazing has been, and continues to be, a major contributor to riparian habitat loss and degradation (NAS 2002, p. 161; Johnson et al. 2007, p. 61).
Large areas of cottonwood-willow floodplain vegetation have been converted to agricultural uses, further reducing the extent of habitat available to western yellow-billed cuckoos for breeding (Swift 1984, pp. 225-226;
Although most riparian and thorn scrub habitat losses largely stem from past agricultural clearing, effects from cultivated agricultural lands are ongoing. Agricultural lands continue to dominate much of the remaining riparian landscape, particularly along the Sacramento (Greco 1999, pp. 94, 104, 107), parts of the Gila, and lower Colorado Rivers (Johnson et al. 2007, p. 207); along the latter, 65 percent of western yellow-billed cuckoo survey sites are bordered on at least one side by agriculture fields (Johnson et al. 2007, p. 61). Riparian areas are sometimes viewed as a potential source of plant and animal pests, a source of shade that may reduce crop yields, and competition for scarce water resources (NAS 2002, pp. 170-171). For example, in the
Accidental fire from farm workers operating machinery or burning weeds sporadically escapes into adjacent riparian habitat. Recent fires on western yellow-billed cuckoo and southwestern willow flycatcher conservation properties occurred in 2011, burning 58 ac (24 ha) and 6 ac (2 ha), respectively, within the
Other ongoing effects from cultivated agriculture on the western yellow-billed cuckoo are addressed under Factor E. These include fragmentation of habitat into smaller, more widely disjunct patches; ongoing influence of agriculture on riparian bird community composition; and effects from pesticides, which can negatively impact insect prey populations of the western yellow-billed cuckoo.
Domestic livestock grazing is a traditional agricultural land use practice in the southwestern
The Service (2002, Appendix G, pp. 5-7) and Krueper et al. (2003, p. 608) reviewed the effects of livestock grazing, primarily in southwestern riparian systems. The frequency and intensity of effects vary across the range of the species, due to variations in grazing practices, climate, hydrology, ecological setting, habitat quality, and other factors (Service 2002, Appendix G, p. 1). However, these effects generally include the removal and trampling of vegetation and compaction of underlying soils, which can inhibit germination and change hydrology (Rea 1983, p. 40; Belsky et al. 1999, pp. 419-431) and promote the dispersal of nonnative plant species. Such effects are most significant when riparian areas have been subject to overuse by livestock (NAS 2002, pp. 24, 168-173). Overuse occurs when grazed vegetation does not recover sufficiently to maintain itself and soils are left bare and vulnerable to erosion. Over time, livestock grazing in riparian habitats, combined with other alterations in streamflow, typically results in reduction of plant species diversity and density and may increase the distribution and density of nonnative tamarisk by eliminating competition from native cottonwood and willow saplings, which are preferred forage for livestock (Krueper et al. 2003, p. 608).
Long-term cumulative effects of livestock grazing involve changes in the structure and composition of riparian vegetation (Service 2002, Appendix G, pp. 5-7), which may affect suitability of habitat for western yellow-billed cuckoo breeding and prey population abundance. The western yellow-billed cuckoo nesting habitat is structurally complex with tall trees, a multistoried vegetative understory, low woody vegetation (Halterman 1991, p. 35) and higher shrub area than sites without western yellow-billed cuckoos (
Removal, reduction, or modification of cattle grazing has resulted in increases in abundance of some riparian bird species. For example, Krueper (1993, pp. 322-323) documented responses of 61 bird species, most of which increased significantly 4 years after removal of livestock grazing in
In another example, livestock grazing was terminated along portions of the
In conclusion, most of the direct loss of habitat from agricultural conversion has occurred in the past, but ongoing agricultural activities, in whole or in combination with other impacts, especially those that result in changes in a watercourse's hydrology, have resulted in the curtailment of nesting and foraging habitat for the western yellow-billed cuckoo by restricting or preventing the growth of riparian plants, and such activities present an ongoing threat. Most of the current impacts from agricultural land uses arise from livestock overgrazing in riparian areas. Riparian vegetation can recover relatively quickly from these effects after livestock removal (Smith 1996, p. 4; Krueper et al. 2003, p. 615). However, without proper management to reduce overgrazing, ongoing overgrazing will continue to contribute to habitat modification in the range of the western yellow-billed cuckoo into the future.
Throughout most of its range, habitat for the western yellow-billed cuckoo is threatened by the conversion of native riparian woodlands to riparian vegetation dominated by tamarisk and other nonnative vegetation. The major threat from this habitat conversion is the change from vegetation that supplies the western yellow-billed cuckoos with essential food and adequate thermal cover to vegetation that does not provide these necessary components of habitat for the western yellow-billed cuckoo. The establishment and persistence of tamarisk is often, but not always, aided by altered hydrology, as described above. Altered hydrology is not the cause for establishment and persistence of other types of nonnative vegetation; therefore, we present information on nonnative vegetation in this separate section.
Tamarisk is the most widespread nonnative woody plant species found in habitat for the western yellow-billed cuckoo. Glenn and Nagler (2005, pp. 420-423) provide most of the following overview of tamarisk. Tamarisk is present in nearly every southwestern riparian plant community, but varies in dominance from stream to stream. On streams where altered hydrology can no longer support native species, it has replaced native plant communities entirely, but occurs at a low frequency on other streams. Tamarisk was introduced into western
Tamarisk also occurs as isolated individuals along sections of the
The threshold (in terms of percent tamarisk) for abandonment of a riparian system by western yellow-billed cuckoos is not known. They are not found in areas that are totally dominated by tamarisk with the complete lack of willows or cottonwoods. In
Human disturbance, such as water diversion, flood control, vegetation clearing, and improper grazing management, often facilitates replacement of native vegetation with tamarisk (Kerpez and Smith 1987, pp. 1-5; Hunter et al. 1988, p. 113;
Tamarisk is also tolerant of high salt levels, which can be present in river systems as a combined result of water diversions that lower the near-surface ground water and irrigation water runoff that contains high levels of dissolved salts (Kerpez and Smith 1987, pp. 1-5; Busch and Smith 1993, pp. 186-194). This higher tolerance to water stress and salt accumulation is a principle mechanism by which tamarisk has become dominant on some regulated western rivers (Glenn and Nagler 2005, p. 439). In addition, tamarisk takes salts from the ground water and exudes them from its leaves, rendering the soil even more unsuitable for germination of native riparian vegetation. This is a significant problem in streams with artificially reduced streamflows where salts accumulate and are not flushed from the system. These factors favor regeneration of tamarisk over native trees and shrubs and are an ongoing threat. Additional areas of native habitat are continuing to be lost to this process. In summary, the persistence and expansion of tamarisk-dominated habitat is the result of multiple forms of ongoing human-related disturbances, which result in degradation of native-dominated riparian habitat, thus reducing its suitability as breeding habitat for the western yellow-billed cuckoo.
Other nonnative tree and shrub species have become established within the range of the western yellow-billed cuckoo. In western
In conclusion, because of the absence or near absence of nesting by western yellow-billed cuckoos in nearly monotypic stands of tamarisk and other nonnative vegetation, the available literature suggests that conversion of native or mixed (native and nonnative) riparian woodlands to nearly monotypic stands of tamarisk and other nonnative vegetation, coupled with the inability of native vegetation to regenerate under altered hydrological conditions, is a significant threat to the western yellow-billed cuckoo now and in the future. Nonnative vegetation, such as tamarisk, occurs across most of the range of the western yellow-billed cuckoo; its establishment can be caused by altered hydrology or other disturbances, which are widespread throughout the range. We expect nonnative vegetation to increasingly modify and curtail habitat for the western yellow-billed cuckoo within a majority of its range in
Use of Tamarisk by Western Yellow-Billed Cuckoos and the Spread of the Introduced Tamarisk Leaf Beetle Into the Southwest
Western yellow-billed cuckoos use habitat with some tamarisk component for nesting in southern
Tamarisk can add to foliar cover that contributes toward reducing temperatures in riparian areas (Paxton et al. 2011, p. 259). Even relatively small decreases in foliar cover may render a site unsuitable for nesting western yellow-billed cuckoos (Paxton et al. 2011, p. 260). Removal of tamarisk in drainages occupied by western yellow-billed cuckoos can have unintended negative consequences if the removal leaves little or no woody vegetation and native riparian vegetation is unable to reestablish. The available literature that pertains to riparian restoration in
Tamarisk leaf beetle insects (leaf beetles) (Diorhabda spp.) were released into many locations throughout the southwest to control tamarisk. Leaf beetles are now spreading within the more arid range of the western yellow-billed cuckoo in
Historically, wildfire was uncommon in native riparian woodlands (Busch and Smith 1993, pp. 186-194). However, the lack of scouring floods on regulated and unregulated rivers has resulted in the accumulation of fuel on the floodplain, which increases fire risk and intensity (Stromberg and Chew 2002, pp. 195-219). Water withdrawal, dams, climate change, drought, and human use also contribute toward an increased fuel load and probability of wildfire occurrence. Most fires today are human-caused (Service 2002, p. L-8). In degraded habitat with tamarisk the threat of fire may be greater. Tamarisk ignites quickly, further increasing the incidence of periodic fires. Exacerbating the immediate loss of native trees from fire, tamarisk recovers more quickly than native trees (Glenn and Nagler 2005, pp. 435-436). Along the
Environmental Impacts of Cross-Border Foot Traffic in the Southwest
The environmental impact caused by cross border foot traffic has been increasingly occurring in more fragile and remote areas. The number of
Human-caused wildland fires have been particularly damaging to areas of riparian habitat in
Climate change may be impacting the western yellow-billed cuckoo. Climate change is discussed here under Factor A because, although it may affect the western yellow-billed cuckoo directly by creating physiological stress, the primary impacts of climate change on the species are expected to be through changes in the availability and distribution of western yellow-billed cuckoo habitat.
Our analyses under the Act include consideration of ongoing and projected changes in climate. The terms "climate" and "climate change" are defined by the
Scientific measurements spanning several decades demonstrate that changes in climate are occurring, and that the rate of change has increased since the 1950s. Examples include warming of the global climate system, and substantial increases in precipitation in some regions of the world and decreases in other regions (for these and other examples, see Solomon et al. 2007, pp. 35-54, 82-85; IPCC 2013b, pp. 3-29; IPCC 2014, pp. 1-32). Results of scientific analyses presented by the IPCC show that most of the observed increase in global average temperature since the mid-20th century cannot be explained by natural variability in climate and is "very likely" (defined by the IPCC as 90 percent or higher probability) due to the observed increase in greenhouse gas (GHG) concentrations in the atmosphere as a result of human activities, particularly carbon dioxide emissions from use of fossil fuels (Solomon et al. 2007, pp. 21-35; IPCC 2013b, pp. 11-12 and figures SPM.4 and SPM.5). Further confirmation of the role of GHGs comes from analyses by Huber and Knutti (2011, p. 4), who concluded it is extremely likely that approximately 75 percent of global warming since 1950 has been caused by human activities.
Scientists use a variety of climate models, which include consideration of natural processes and variability, as well as various scenarios of potential levels and timing of GHG emissions, to evaluate the causes of changes already observed and to project future changes in temperature and other climate conditions (Meehl et al. 2007, entire; Ganguly et al. 2009, pp. 11555, 15558; Prinn et al. 2011, pp. 527, 529). All combinations of models and emissions scenarios yield very similar projections of increases in the most common measure of climate change, average global surface temperature (commonly known as global warming), until about 2030. Although projections of the magnitude and rate of warming differ after about 2030, the overall trajectory of all the projections is one of increasing global warming through the end of this century, even for the projections based on scenarios that assume that GHG emissions will stabilize or decline. Thus, there is strong scientific support for projections that warming will continue through the 21st century, and that the magnitude and rate of change will be influenced substantially by the extent of GHG emissions (Meehl et al. 2007, pp. 760-764, 797-811; Ganguly et al. 2009, pp. 15555-15558; Prinn et al. 2011, pp. 527, 529; IPCC 2013b, pp. 19-23). See IPCC 2013b (entire), for a summary of other global projections of climate-related changes, such as frequency of heat waves and changes in precipitation.
Various changes in climate may have direct or indirect effects on species. These effects may be positive, neutral, or negative, and they may change over time, depending on the species and other relevant considerations, such as threats in combination and interactions of climate with other variables (for example, habitat fragmentation) (IPCC 2014, pp. 4-11). Identifying likely effects often involves aspects of climate change vulnerability analysis. Vulnerability refers to the degree to which a species (or system) is susceptible to, and unable to cope with, adverse effects of climate change, including climate variability and extremes. Vulnerability is a function of the type, magnitude, and rate of climate change and variation to which a species is exposed, its sensitivity, and its adaptive capacity (
Global climate projections are informative, and, in some cases, the only or the best scientific information available for us to use. However, projected changes in climate and related impacts can vary across and within different regions of the world (IPCC 2013b, pp. 15-16). Therefore, we use "downscaled" projections when they are available and have been developed through appropriate scientific procedures, because such projections provide higher resolution information that is more relevant to spatial scales used for analyses of a given species (see
The Southwest is already experiencing the impacts of climate change. The region has heated up markedly in recent decades, and the period since 1950 has been hotter than any comparably long period in at least 600 years (Graumlich 1993, pp. 249-255;
There are three predictions for anticipated effects from climate change in the southwestern
Precipitation events under most climate change scenarios will decrease in frequency but increase in severity so that, paradoxically, a warmer atmosphere and an intensified water cycle are likely to mean not only a greater likelihood of drought for the Southwest, but also an increased risk of flooding (Karl et al. 2009, pp. 132-133;
Exactly how climate change will affect precipitation from site to site within the range of the western yellow-billed cuckoo in the southwestern
Assessments for the Sonoran Desert are few, but the region is also expected to warm (Weiss and Overpeck 2005, pp. 2065-2077;
In California, regional downscaled climate change assessments (
Regionally downscaled climate models for the
In drier climates overall, there will be increases in riverine system temperatures that are predicted to result in periods of prolonged low flows and stream drying (Stromberg et al. 2013, pp. 411-415) and increased demand for water storage and conveyance systems (Stromberg et al. 2013, pp. 411-415). Warmer water temperatures across temperate regions are likely to increase the density and expand distribution of tamarisk because it has a higher tolerance for drought and salt than native cottonwoods and willows (Glenn and Nagler 2005, p. 439). This situation is expected to lead to the conversion of native and mixed (native and nonnative) riparian habitat to monotypic stands of tamarisk, which provides very little or no suitable breeding habitat for the western yellow-billed cuckoo (as described previously above).
Increased drought is expected to adversely affect food availability for western yellow-billed cuckoos (Newton 1980, pp. 11-12; Durst 2004, pp. 40-41; Scott et al. 2004, p. 70) through the disruption of the timing between a species and its food resources (Visser and Both 2005, pp. 2561-2569). For example, changes in precipitation or temperature may influence the peak timing of insect emergence or timing of the western yellow-billed cuckoo's arrival from its wintering grounds so that the nesting season does not coincide as closely with peak insect abundance (Anders and Post 2006, p. 225). This change in timing could result in reduced food availability for the western yellow-billed cuckoo and breeding success, possibly causing further population decline and curtailment of its occupied range.
Virtually all future climate scenarios for the
Little is known about the wintering habitat of the western yellow-billed cuckoo in
In summary, the available climate change models are predicting altered future environmental conditions across the breeding range of the western yellow-billed cuckoo. In the southwestern
Impacts to habitat from climate change exacerbate impacts from impoundments, channelization, and alteration of river flows across the western
Summary of Factor A
We have identified a number of threats to the habitat of the western yellow-billed cuckoo that have operated in the past, are impacting the species now, and will continue to impact the species in the future. The curtailment and decline in the habitat of the western yellow-billed cuckoo is primarily the result of the long-lasting effects of habitat loss from manmade features that alter watercourse hydrology so that the natural processes that sustained riparian habitat in western
We recognize that climate change is a critical issue with potentially severe wide-ranging effects on the species and its habitat. The available scientific literature suggests that the effects of climate change will likely exacerbate multiple existing threats to the western yellow-billed cuckoo and its habitat. These threats include habitat loss and degradation from altered hydrology, with secondary effects from increases in nonnative vegetation and wildfire. These threats may result in smaller patch sizes of habitat such that many will be no longer occupied by the western yellow-billed cuckoo.
Conservation actions, such as habitat protection and restoration described above, have strong potential to be beneficial to the species by increasing the amount of available habitat and patch size. However, these efforts offset only a small portion of past losses and degradation of riparian habitat in the range of the western yellow-billed cuckoo. Habitat elsewhere in the range continues to be vulnerable to loss and degradation from ongoing alterations in hydrology, nonnative vegetation, and agricultural activities combined with additional or synergistic effects associated with climate change. Moreover, we expect these multiple stressors to continue to affect habitat of the western yellow-billed cuckoo into the future. The amount of time required for willow and cottonwood vegetation to mature and provide habitat for the western yellow-billed cuckoo under optimal hydrologic, environmental, and ecological conditions varies by location but may be as little as between 3 to 5 years (Golet et al. 2008, pp. 20-22). However, other vegetation used by the western yellow-billed cuckoo such as alder, walnut, sycamore, boxelder, ash, or mesquite would take several decades for habitat to mature to the point where it would be available for use (Strahan 1984, pp. 58-67; Opperman and Merenlender 2004, pp. 822-834;
The exact timeframe for resolving water management and delivery issues and their impact on the western yellow-billed cuckoo and its habitat would vary on the location, resource demands, sensitive habitat or species concerns, stakeholders, and amount of water available. As a result, we would expect that resolving water issues for the various uses (agriculture, urbanization, wildlife, and tribal interests) in the west will be a lengthy ongoing process and not be resolved in the near future (next 20 years) and may take substantially longer considering the increased demands and the effects of climate change.
Our review of the best available scientific and commercial information identified numerous activities or processes that threaten to destroy, modify, or curtail the western yellow-billed cuckoo's habitat or range now or are likely to in the near future in any portion of the western yellow-billed cuckoo range. These include habitat loss from reservoirs and water management, surface and groundwater diversion, flood control activities, gravel mining, agriculture, livestock grazing, invasive nonnative plants and their control, and climate change. We, therefore, conclude that habitat loss under Factor A currently constitutes a threat to the western yellow-billed cuckoo, and we expect these activities to continue and habitat loss to be a threat in the near future.
B. Overutilization for Commercial, Recreational, Scientific, or Educational Purposes
There are no known threats to the western yellow-billed cuckoo resulting from overutilization for commercial, scientific, or educational purposes. Our review of the best available scientific and commercial information yielded nothing to indicate that overutilization for commercial, recreational, scientific, or educational purposes is occurring at this time or is likely to in the near future in any portion of the western yellow-billed cuckoo range. We, therefore, conclude that such overutilization does not currently constitute a threat to the western yellow-billed cuckoo, nor do we expect it to be a threat in the future.
C. Disease or Predation
Little is known about diseases in the western yellow-billed cuckoo. West Nile virus has recently spread throughout portions of the western
All bird species, including the yellow-billed cuckoo, are exposed, to some extent, to parasites.
Predation is a potential threat to the western yellow-billed cuckoo. On the
On the lower
In summary, western yellow-billed cuckoos, particularly the eggs or young in nests, are vulnerable to predation. Predation may be a significant threat in some localities and in some years, and may be influenced by several factors, such as surrounding land use and size and complexity of riparian habitat. As a result, predation may act periodically in concert with other stressors that contribute to the decline of the species (which we discuss in greater detail under Factor E, below). However, we conclude that predation by itself does not pose a significant threat to the western yellow-billed cuckoo at this time, and we do not have any reason to believe that this situation will change substantially in the future.
We conclude that predation, parasites, and disease are not currently significant threats to the western yellow-billed cuckoo, and are not expected to become significant threats in the near future.
D. The Inadequacy of Existing Regulatory Mechanisms
Under this factor, we examine whether existing regulatory mechanisms are inadequate to address the threats to the western yellow-billed cuckoo discussed under other factors. We give strongest weight to statutes and their implementing regulations, and management direction that stems from those laws and regulations. They are nondiscretionary and enforceable, and are considered a regulatory mechanism under this analysis. Examples include State governmental actions enforced under a State statute or constitution, or Federal action under statute.
Some other programs are more voluntary in nature or dependent on available funding; in those cases, we analyze the specific facts for that effort to ascertain its effectiveness at mitigating the threat and the extent to which it can be relied on in the future. Having evaluated the significance of the threat as mitigated by any such conservation efforts, we analyze under Factor D the extent to which existing regulatory mechanisms adequately address the specific threats to the species. Regulatory mechanisms, if they exist, may preclude the need for listing if we determine that such mechanisms adequately address the threats to the species such that listing is not warranted.
We have identified a number of significant threats to the western yellow-billed cuckoo that are impacting the species now and will continue to impact the species in the future. The decline of the western yellow-billed cuckoo is primarily the result of the long-lasting effects of habitat loss and modification from altered hydrology resulting from decades of dam construction, channelization, water extraction, and other activities, as well as impacts associated with climate change. Other threats include loss of habitat to agricultural and other land uses, overgrazing, exposure to pesticides (which is addressed in Factor E, below), wildfire, and conversion of habitat to monotypic stands of nonnative vegetation. Under this factor, we discuss whether the existing regulatory mechanisms adequately address impacts to the western yellow-billed cuckoo described under Factors A and E, based on the best available information.
Federal Regulatory Mechanisms
In the United States, the Migratory Bird Treaty Act (MBTA) (16 U.S.C. Sec. 703-712) is the only current Federal protection provided for the yellow-billed cuckoo. The yellow-billed cuckoo (the entire taxonomically defined species), which includes the western yellow-billed cuckoo, is considered a "migratory bird" under the MBTA. The MBTA prohibits "take" of any migratory bird. Take is defined as: "to pursue, hunt, shoot, wound, kill, trap, capture, or collect, or attempt to pursue, hunt, shoot, wound, kill, trap, capture, or collect." However, no provisions in the MBTA prevent habitat destruction unless direct mortality or destruction of active nests occurs.
The Federal Land Policy and Management Act of 1976 (FLPMA) (43 U.S.C.
Congress passed the Federal Water Pollution Control Act Amendments of 1972 and the Clean Water Act (CWA) of 1977 (33 U.S.C.
Section 404 prohibits the discharge of dredged or fill material in jurisdictional waters of
Furthermore, not all activities in wetlands or streams involve fill, and not all wetlands or streams fall under the jurisdiction of the USACE. For example, in areas where the historical floodplain has been cut off from the river by levees, determining the boundaries of wetlands subject to USACE jurisdiction becomes complex. The areas behind these levees have had their hydrological characteristics altered, soil conditions changed, and riparian vegetation removed. As a result, these former floodplains, which in some cases would be important to protect and restore as habitat for the western yellow-billed cuckoo, fall outside the jurisdiction of the USACE. Additionally, many actions that resulted in adverse hydrological modifications, such as channelization and levees, were implemented in compliance with the CWA.
The National Environmental Policy Act (NEPA) (42 U.S.C. 4321 et seq.) requires all Federal agencies to formally document, consider, and publicly disclose the environmental impacts of major Federal actions and management decisions that have significant effects on the human environment (including natural resources); however, NEPA does not require that mitigation alternatives be implemented. Additionally, NEPA applies only to actions by Federal agencies, so private landowners are not required to comply with NEPA unless a Federal agency is involved through provision of Federal funding or a Federal permit.
Through the Fish and Wildlife Coordination Act (FWCA) (16 U.S.C. 661 et seq.), the Service may recommend discretionary conservation measures to avoid, minimize, and offset impacts to fish and wildlife resources resulting from Federal projects and water development projects authorized by the USACE and other Federal agencies such as Reclamation. Therefore, the FWCA may provide some protection for the western yellow-billed cuckoo and its habitat through avoidance and minimization measures that may be incorporated into Federal projects. However, these measures are discretionary.
A majority of dams in the western
The EPA is responsible for regulating pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act and the Food Quality Protection Act. Before a pesticide can be distributed, sold, and used in
State Regulatory Mechanisms
The majority of occupied areas for the western yellow-billed cuckoo north of
The State of California has an additional layer of pesticide regulation through the
The western yellow-billed cuckoo is identified as a Species of Greatest Conservation Need in
In Nevada, the western yellow-billed cuckoo is identified as critically imperiled due to extreme rarity, imminent threats, or biological factors, but this designation provides no protection for habitat. Western yellow-billed cuckoos have no State status in
In summary, where the western yellow-billed cuckoo is State-listed (CA), a State candidate (WA), a species of concern or sensitive species (AZ, ID, WY, MT, CO, TX), or critically imperiled (NV), these designations contain no protection for the western yellow-billed cuckoo from habitat modification or destruction, as described under Factors A and E. Existing State regulatory mechanisms are not specifically designed to protect the western yellow-billed cuckoo from habitat loss and degradation from altered hydrology from upstream dams and surface water and ground water diversions, encroachment into the floodplain by agricultural and other development activities, bank stabilization and levee construction and maintenance activities, overgrazing, pesticide use on adjacent agricultural lands, conversion of habitat to monotypic stands of nonnative vegetation, gravel mining, wildfire, drought, and climate change across the range of the western yellow-billed cuckoo.
Canadian, Mexican, and Other International Laws
The Canadian Government through the
The Species at Risk Act of 2002. The purpose of the Species at Risk Act (SARA) is to prevent Canadian native wildlife and plant species, subspecies, and distinct populations from becoming extirpated or extinct, to provide for the recovery of endangered or threatened species, and encourage the management of other species to prevent them from becoming at risk. SARA establishes the Committee on the Status of Endangered Wildlife in
The yellow-billed cuckoo is not identified as a species that is sensitive, threatened, or endangered under Canadian law. Within the range of the western yellow-billed cuckoo,
Canadian Environmental Protection Act of 1999. The Canadian Environmental Protection Act sets out several guiding principles for conserving the environment including but not limited to supporting: Sustainable development; pollution prevention; elimination of releases of substances that are persistent or that bioaccumulate; an ecosystem approach and using the precautionary principle on issues related to the environment; science-based national standards; and seeking intergovernmental cooperation for consistency and avoidance of duplication of efforts. Because the yellow-billed cuckoo is not considered a species at risk, implementation of environmental protection regulations are optional for the species.
The Mexican Government, through its Secretaria de Medio Ambiente y
In 1988, the Mexican Government passed the General Law of Ecological Equilibrium and Environmental Protection, which is similar to NEPA in
The National Natural Protected Areas (NPAs) system is a Mexican program to protect sensitive habitats and species. NPA designation is supposed to protect areas that have not been significantly altered by human activities and that provide diverse ecosystem services. However, prior to 1994, most NPAs lacked sound and comprehensive management plans. By 2000, approximately 30 percent of new and existing NPAs had developed management plans; however, under the NPA model these plans lacked detailed information, and in many cases could be considered obsolete. NPA goals to promote sustainable natural resources are often unattainable because of conflicting land ownership interests (
Wildlife management units, or UMAs, were part of a program developed and implemented by SEMARANT in 1997 to promote wildlife management on private property in
Current efforts for protecting the western yellow-billed cuckoo in
Lack of habitat protection for the western yellow-billed cuckoo in northwestern
In regard to potential for pesticide exposure south of the U.S. border,
Based on the best available information, the regulatory mechanisms in
Summary of Factor D
Various Federal, State, and international regulatory mechanisms in place provide varying degrees of conservation oversight that may to some degree address the threat of ongoing habitat loss and degradation resulting from altered hydrology, conversion of habitat to nonnative vegetation, climate change, agricultural activities (Factor A), or exposure to pesticides and effects of small and isolated habitat patches (Factor E). In
Because the yellow-billed cuckoo is not a protected or sensitive species in
E. Other Natural or Manmade Factors Affecting Its Continued Existence
Small and Widely Separated Habitat Patches
As described in the Background section and under Factor A, the habitat of the western yellow-billed cuckoo has undergone significant loss and modification within its occupied breeding range as a result of widespread multiple human-caused effects. These include altered hydrology in watercourses and past loss and degradation from agriculture. Past destruction and modification transformed formerly large expanses of riparian habitat into a number of smaller patches of smaller total area, isolated from each other by a matrix of mostly human-altered habitats (
As a result, the western yellow-billed cuckoo now primarily occurs in smaller, more widely separated populations. Compared to large populations, smaller populations are disproportionately affected by natural and manmade factors. These stressors vary in frequency, timing, and magnitude across the species' range. They are related or correlated to each other or act in combination to result in significant impacts to the western yellow-billed cuckoo within all or portions of its range.
One of the ramifications of smaller, more isolated habitat patches is that the smaller the patch, the more edge it has in proportion to its area, which increases the percentage of the available habitat exposed to the surrounding land uses (Hunter 1996, pp. 186-187). This is a particularly prevalent characteristic of the western yellow-billed cuckoo's remaining disjunct habitat patches, as many patches are in proximity to agricultural and other human-altered landscapes. For example, such land use currently dominates much of the riparian landscape within many regions, particularly along some reaches of the lower
Agricultural activities on adjacent lands affect riparian bird communities in ways that may result in lower reproductive success, and possible abandonment of the patch, as reviewed by
The western yellow-billed cuckoo is currently found in the largest contiguous and least-fragmented remaining habitat patches. For example, in
Moreover, isolated breeding sites separated by hundreds of miles of nonhabitat also reduce the ease with which dispersing juvenile and returning adult western yellow-billed cuckoos are able to find these sites. This isolation may result in low colonization and reoccupation rates, so that otherwise suitable habitat remains unoccupied or occupied at low densities (Laymon and Halterman 1989, p. 274; Hunter 1996, p. 185). For example, the Sacramento River still appears to have sufficient habitat to maintain a self-sustaining population of western yellow-billed cuckoos, as more than 25,000 ac (10,117 ha) of riparian and associated natural habitat has been protected and other sections are in the process of being restored. However, not all suitable patches are occupied or may only be occupied in very low densities, and the western yellow-billed cuckoo population remains much lower than its potential (Dettling and
In summary, despite efforts to protect and restore riparian habitat along the Sacramento River and Colorado River and elsewhere in the range of the western yellow-billed cuckoo, these efforts offset only a small fraction of historical habitat that has been lost. Therefore, the threats resulting from the species' behavioral response to the multiple, combined effects of small and widely separated habitat patches exacerbate the effect of other threats within a large portion of the range of the western yellow-billed cuckoo. Moreover, because the threats that create small and isolated patches are ongoing (see Factor A) and maturation of regenerated or restored habitat may take several decades to fully provide for the needs of the species, we expect the effects of the species' response to small patch size to continue to adversely impact the western yellow-billed cuckoo into the future.
Exposure to pesticides may also be a threat to western yellow-billed cuckoos because it negatively impacts populations of insect prey (Groschupf 1987, p. 29; Hughes 1999, p. 2). The effects of pesticides on western yellow-billed cuckoos can be from intentional aerial spraying of habitat for mosquito or forest pest control, or from overspray or drift when the species' foraging habitat is located next to agricultural fields. Pesticides can affect western yellow-billed cuckoos foraging for grasshoppers at the field-forest interface or foraging for caterpillars in riparian habitat adjacent to the sprayed fields. Accumulation of chlorinated hydrocarbon pesticides, particularly dichlorodiphenyltrichloroethane (DDT), has affected other bird species, particularly top predators (
Western yellow-billed cuckoo prey populations were affected by aerial spraying of larvicides for control of mosquitoes at
Effects from overspray of pesticides are more pronounced in smaller patches next to agricultural fields (because they have more edges, which allows for increased chances of exposure), but the effects of pesticides could also affect larger habitat patches as well. In many areas riparian habitat borders agricultural lands, such as
Although DDT use has been banned in
For example, yellow-billed cuckoos (most likely of the eastern population) collected during the spring and fall migration in
A recent study in southern
Neonicotinoid pesticides are systemic chemicals that are taken up through various plant parts and can be distributed through a plant's tissues. These chemicals can be applied to a plant as a seed coating, soil contact, irrigation water, or as a foliar spray. Many of these chemicals are long acting with half-lives up to 2 years. Plant tissues that have been treated are toxic to both sap-sucking (e.g., aphids and true bugs) and foliage-eating insects (e.g., caterpillars, katydids, grasshoppers, and beetles). Many of these foliage-eating insects are potential prey of the western yellow-billed cuckoo. These chemicals have the potential to reduce prey abundance if intentionally or accidentally applied to foliage on which western yellow-billed cuckoos forage. To date no scientific studies have been done on western yellow-billed cuckoos and their prey, but additional reports and research on these chemicals discuss the potential adverse effects (Mineau and
In summary, pesticide use is widespread in agricultural areas in the western yellow-billed cuckoo breeding range in
Yellow-billed cuckoos are vulnerable to collision with communication towers and other tall structures, particularly during their migration. For example, several hundred yellow-billed cuckoo mortalities were documented at a single television tower in
Conservation Efforts To Reduce Other Natural or Manmade Factors Affecting Its Continued Existence
Active and hydrological process-based restoration of riparian habitat on the
At present, restoration occurs on a relatively small scale in comparison to the need to reduce habitat fragmentation and increase the overall extent of suitable habitat. Future process-based restoration projects that restore natural river hydrology show great promise for large-scale restoration of riparian habitat for western yellow-billed cuckoos.
To date, conservation efforts, though helpful, have been inadequate to significantly reduce the effects of natural or manmade factors affecting the western yellow-billed cuckoo.
Summary of Factor E
As noted in Factor A, habitat for the western yellow-billed cuckoo has been modified and curtailed, resulting in only remnants of formerly large tracts of native riparian forests, many of which are no longer occupied by western yellow-billed cuckoos. Despite recent efforts to protect existing, and restore additional, riparian habitat in the Sacramento,
Habitat loss and degradation occurs throughout the range of the western yellow-billed cuckoo (see Background section and Factor A above), and many of the threats under Factor A have worked and are working in combination to reduce the amount, configuration, and quality of the riparian habitat that remains.
This array of Factor A threats, working in combination, creates the situation that then allows threats from the other listing factors to markedly affect the species. These other-factor threats may not be significant in and of themselves, but because they are not occurring in isolation they, in combination, are contributing to the population decline of the species. For example, as discussed in the Small and Widely Separated Habitat Patches section of Factor E, above, small habitat patches (resulting from the effects of Factor A threats) are more likely to have a larger number and a wider range of nest predators (see the Predation section of Factor C, above) because more nest predators occur in ecological edges. Additionally, habitat patches near areas of agricultural or urban development can foster higher densities of potential nest predators. Thus, any western yellow-billed cuckoo nesting in a small habitat patch near development may be subject to higher levels of nest predation and thus lower productivity. Moreover, the mere presence of certain nest predators in a habitat patch may elicit a behavioral response from western yellow-billed cuckoos such that they do not even attempt to nest in such habitat patches, even if other aspects of the habitat would suggest that it is suitable for nesting.
Similarly, riparian habitat patches that occur near urban and agricultural development may be subject to intentional or accidental pesticide spraying, as discussed in the Pesticide section under Factor E. This spraying would be unlikely to occur but for the habitat patch's proximity to development. This development likely occurs close to the riparian habitat through a process similar to the generalized scenario described above (see also specific details under Factor A).
Much of the available habitat is now in small patches with only a relatively few patches regularly occupied by nesting western yellow-billed cuckoos. Thus, the species' intolerance of small patch size in combination with extensive habitat loss has resulted in much less suitable habitat and a greatly reduced western yellow-billed cuckoo population size. In areas at the edge of the western yellow-billed cuckoo's current range (e.g., the Sacramento River), restoration of riparian habitat has not been accompanied by an increase in the species' population indicating that other factors may be limiting the population in those areas. Moreover, large areas of suitable habitat are unlikely to naturally regenerate within the range of the species into the future because western yellow-billed cuckoos need riparian habitat in a range of ages, including older, more structurally diverse areas for nesting, and nearly all of the areas where riparian habitat could grow in western
Summary of Factors
The primary factors threatening the western DPS of the yellow-billed cuckoo are the loss and degradation of habitat for the species from altered watercourse hydrology and natural stream processes, livestock overgrazing, encroachment from agriculture, and conversion of native habitat to predominantly nonnative vegetation as identified in Factor A. Additional threats to the species under Factor E include the effects of climate change, pesticides, wildfire, and small and widely separated habitat patches. The cumulative impact from various threats is also a factor that will exacerbate multiple existing threats to the western yellow-billed cuckoo and its habitat.
Various Federal, State, and international regulatory mechanisms in place provide varying degrees of conservation oversight that may to some degree address the threat of ongoing habitat loss and degradation; however, because the yellow-billed cuckoo is not a protected or sensitive species in a majority of
These factors pose current and future threats to the species because they are ongoing and likely to continue in the near future.
We have carefully assessed the best scientific and commercial data available regarding the past, present, and reasonably anticipated future threats to the western yellow-billed cuckoo. In assessing the status of the western yellow-billed cuckoo, we applied the general understanding of "in danger of extinction" discussed in the
Factor A threats result from habitat destruction, modification, and degradation from dam construction and operations, water diversions, riverflow management; stream channelization and stabilization; conversion to agricultural uses, such as crops and livestock grazing; urban and transportation infrastructure; and increased incidence of wildfire. Continuing ramifications of actions that caused habitat loss in the past have resulted in ongoing curtailment of the habitat of the western yellow-billed cuckoo throughout its range. These factors also contribute to fragmentation and promote conversion to nonnative plant species, particularly tamarisk. The threats affecting western yellow-billed cuckoo habitat are ongoing and significant and have resulted in curtailment of the range of the species. Loss of riparian habitat leads not only to a direct reduction in western yellow-billed cuckoo numbers but also leaves a highly fragmented landscape, which in combination with other threats (see below), can reduce breeding success through increased predation rates and barriers to dispersal by juvenile and adult western yellow-billed cuckoos.
Factor E threats, including habitat rarity and small and isolated population sizes, cause the remaining western yellow-billed cuckoo populations to be increasingly susceptible to further declines through lack of immigration, reduced populations of prey species (food items), pesticides, and collisions with tall vertical structures during migration. The serious and ongoing threat of small overall population size, which is the result of other threats in combination, leads to an increased chance of local extirpations.
The threats that affect the western yellow-billed cuckoo are important on a threat-by-threat basis, but are even more significant in combination. Habitat loss has been extensive throughout the range of the western yellow-billed cuckoo. The remaining riparian habitat is fragmented into small patches, which the species does not normally select as breeding habitat. Additionally, western yellow-billed cuckoos need riparian habitat in a range of ages, including older structurally diverse areas for nesting. This diversity of tree ages within the riparian vegetation (western yellow-billed cuckoo's habitat) is largely dependent on disturbances that affect some but not all of the vegetation within that habitat patch at one time. A number of threats, working in combination or individually, prevent such disturbance from happening now and will continue to do so in the future.
For example, dams and other flood control modifications to a watercourse may prevent floods from being severe enough to affect that habitat patch; channelization may restrict floodwaters to a narrow channel, allowing floodwaters to cause too much damage to habitat within the channel and not enough (or no) damage to habitat outside the channel; altered flood regimes may allow dead wood to accumulate, allowing fires, when they occur, to be severe and affect most of the patch; development and other human activities next to habitat patches may allow more wildfires to be ignited; and the reduction in patch size, through neighboring development, alteration of hydrology, or encroachment by nonnative plants, makes it more likely that a larger proportion of that patch will be affected during any given disturbance event. Moreover, nearly all areas where riparian habitat could potentially grow are modified by dams or water withdrawal and disrupted by other activities, often in combination, that prevent the reestablishment of riparian habitat. Patch size, when coupled with habitat loss and Factor C and E threats, including proximity to incompatible land uses, which increases exposure to predators and pesticides, is a significant cumulative threat to the western yellow-billed cuckoo now and in the future.
Per section 4(b)(1)(A) of the Act, prior to making our determination, we must first "[take] into account those efforts, if any, being made by any State or foreign nation, or any political subdivision of a State or foreign nation, to protect such species, whether by predator control, protection of habitat and food supply, or other conservation practices, within any area under its jurisdiction, or on the high seas." Restoration of riparian habitat on the
Through our analysis of the best available scientific and commercial information on the species' abundance, life history, current population status and trends, and the response of the species and its habitat to natural and anthropogenic threats, we have determined that the western yellow-billed cuckoo meets the definition of a threatened species under the Act, rather than endangered. The Act defines an endangered species as any species that is "in danger of extinction throughout all or a significant portion of its range" and a threatened species as any species "that is likely to become endangered throughout all or a significant portion of its range within the foreseeable future."
The geographic extent of the western yellow-billed cuckoo remains rather widespread through much of its historic range, conferring some measure of ecological and geographic redundancy and resilience. Although there is a general decline in the overall population trend and its breeding range has been reduced, the rate of the population decline and contraction of its breeding range is not so severe to indicate extinction is imminent for the western yellow-billed cuckoo. This current downward trend is slow and not expected to increase in the near future. The majority of large-scale habitat losses and conversions through dam building and agricultural development have already occurred, and we are not aware of any large-scale projects that would affect the species to the extent that the current trend of decline would change. Therefore, threats to the species and population declines do not currently reach the level typical of an endangered species.
Because the western yellow-billed cuckoo does not face any known sudden and calamitous threats, it is not a narrowly endemic species vulnerable to extinction from elevated or cumulative threats, is not yet restricted to a critically small range or critically low numbers, and currently does not show any substantial reduction in numbers, it would not meet the definition of "endangered" as determined by the Act. More appropriately, we find that the western yellow-billed cuckoo is likely to become endangered throughout all or a significant portion of its range within the foreseeable future, based on the timing, severity, and scope of the threats described above. Therefore, on the basis of the best available scientific and commercial information, we are listing the western distinct population segment of the yellow-billed cuckoo as a threatened species in accordance with sections 3(6), 3(20), and 4(a)(1) of the Act.
Significant Portion of the Range
Under the Act and our implementing regulations, a species may warrant listing if it is an endangered or threatened species throughout all or a significant portion of its range. The Act defines "endangered species" as any species which is "in danger of extinction throughout all or a significant portion of its range," and "threatened species" as any species which is "likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range." The definition of "species" is also relevant to this discussion. The Act defines "species" as follows: "The term `species' includes any subspecies of fish or wildlife or plants, and any distinct population segment [DPS] of any species of vertebrate fish or wildlife which interbreeds when mature." The phrase "significant portion of its range" (SPR) is not defined by the statute, and we have never addressed in our regulations: (1) The consequences of a determination that a species is either endangered or likely to become so throughout a significant portion of its range, but not throughout all of its range; or (2) what qualifies a portion of a range as "significant."
In determining whether a species is threatened or endangered in a significant portion of its range, we first identify any portions of the range of the species that warrant further consideration. The range of a species can theoretically be divided into portions an infinite number of ways. However, there is no purpose to analyzing portions of the range that are not reasonably likely to be both (1) significant and (2) threatened or endangered. To identify only those portions that warrant further consideration, we determine whether there is substantial information indicating that: (1) The portions may be significant, and (2) the species may be in danger of extinction there or likely to become so within the foreseeable future. In practice, a key part of this analysis is whether the threats are geographically concentrated in some way. If the threats to the species are essentially uniform throughout its range, no portion is likely to warrant further consideration. Moreover, if any concentration of threats applies only to portions of the species' range that are not significant, such portions will not warrant further consideration.
If we identify portions that warrant further consideration, we then determine whether the species is threatened or endangered in these portions of its range. Depending on the biology of the species, its range, and the threats it faces, the Service may address either the significance question or the status question first. Thus, if the Service considers significance first and determines that a portion of the range is not significant, the Service need not determine whether the species is threatened or endangered there. Likewise, if the Service considers status first and determines that the species is not threatened or endangered in a portion of its range, the Service need not determine if that portion is significant. However, if the Service determines that both a portion of the range of a species is significant and the species is threatened or endangered there, the Service will specify that portion of the range as threatened or endangered under section 4(c)(1) of the Act.
We evaluated the current range of the western yellow-billed cuckoo to determine if there is any apparent geographic concentration of threats for the species. The western yellow-billed cuckoos are highly restricted to riparian habitat in their ranges, and the threats occur throughout the species' range. We considered the potential threats due to altered watercourse hydrology and natural stream processes, livestock overgrazing, encroachment from agriculture, conversion of native habitat to predominantly nonnative vegetation, pesticides, wildfire, small and widely separated habitat patches, and the effects of climate change. We found no concentration of threats because of the species' limited and curtailed range, and uniformity of the threats throughout its entire range. Having determined that the western yellow-billed cuckoo is threatened throughout its entire range, we must next consider whether there are any significant portions of the range where the western yellow-billed cuckoo is in danger of extinction or is likely to become endangered in the foreseeable future.
The western yellow-billed cuckoo is highly restricted to riparian habitat, and the threats to the species and its habitat occur throughout its breeding range. Therefore, we assessed the status of the western yellow-billed cuckoo throughout its entire breeding range. The threats to the survival of the species occur throughout the western DPS' breeding range and are not restricted to any particular significant portion of that range. We conclude that what affects the entire breeding portion of the western DPS' range affects the status of the entire western yellow-billed cuckoo throughout its breeding range, including migration corridors and stopover areas. Accordingly, our assessment and proposed determination applies to the western yellow-billed cuckoo throughout its entire breeding range.
We found no portion of the western yellow-billed cuckoo's range where threats are significantly concentrated or substantially greater than in other portions of their range and that factors affecting the species are essentially uniform throughout its range, indicating no portion of the range of the species warrants further consideration of possible endangered or threatened status under the Act. Therefore, we find there is no significant portion of the range of the western yellow-billed cuckoo that may warrant a different status.
Available Conservation Measures
Conservation measures provided to species listed as endangered or threatened under the Act include recognition, recovery actions, requirements for Federal protection, and prohibitions against certain practices. Recognition through listing results in public awareness and conservation by Federal, State, and local agencies; private organizations; and individuals. The Act encourages cooperation with the States and requires that recovery actions be carried out for all listed species. The protection measures required of Federal agencies and the prohibitions against certain activities are discussed, in part, below.
The primary purpose of the Act is the conservation of endangered and threatened species and the ecosystems upon which they depend. The ultimate goal of such conservation efforts is the recovery of these listed species, so that they no longer need the protective measures of the Act. Subsection 4(f) of the Act requires the Service to develop and implement recovery plans for the conservation of endangered and threatened species. The recovery planning process involves the identification of actions that are necessary to halt or reverse the species' decline by addressing the threats to its survival and recovery. The goal of this process is to restore listed species to a point where they are secure, self-sustaining, and functioning components of their ecosystems.
Recovery planning includes the development of a recovery outline shortly after a species is listed and preparation of a draft and final recovery plan. The recovery outline guides the immediate implementation of urgent recovery actions and describes the process to be used to develop a recovery plan. Revisions of the plan may be done to address continuing or new threats to the species, as new substantive information becomes available. The recovery plan identifies site-specific management actions that set a trigger for review of the five factors that control whether a species remains endangered or may be downlisted or delisted, and methods for monitoring recovery progress. Recovery plans also establish a framework for agencies to coordinate their recovery efforts and provide estimates of the cost of implementing recovery tasks. Recovery teams (composed of species experts, Federal and State agencies, nongovernmental organizations, and stakeholders) are often established to develop recovery plans. When completed, the recovery outline, draft recovery plan, and the final recovery plan will be available on our Web site (http://www.fws.gov/endangered), or from our Sacramento Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT).
Implementation of recovery actions generally requires the participation of a broad range of partners, including other Federal agencies, States, Tribal, nongovernmental organizations, businesses, and private landowners. Examples of recovery actions include habitat restoration (e.g., restoration of native vegetation), research, captive propagation and reintroduction, and outreach and education. The recovery of many listed species cannot be accomplished solely on Federal lands because their range may occur primarily or solely on non-Federal lands. To achieve recovery of these species requires cooperative conservation efforts on private, State, and Tribal lands.
Following publication of this final listing rule, funding for recovery actions will be available from a variety of sources, including Federal budgets, State programs, and cost share grants for non-Federal landowners, the academic community, and nongovernmental organizations. In addition, pursuant to section 6 of the Act, the States of Washington, Idaho, Montana, Oregon, California, Nevada, Wyoming, Utah, Colorado, Arizona, New Mexico, and Texas would be eligible for Federal funds to implement management actions that promote the protection or recovery of the yellow-billed cuckoo. Information on our grant programs that are available to aid species recovery can be found at: http://www.fws.gov/grants.
Please let us know if you are interested in participating in recovery efforts for the yellow-billed cuckoo. Additionally, we invite you to submit any new information on this species whenever it becomes available and any information you may have for recovery planning purposes (see FOR FURTHER INFORMATION CONTACT).
Section 7(a) of the Act requires Federal agencies to evaluate their actions with respect to any species that is proposed or listed as endangered or threatened and with respect to its critical habitat, if any is designated. Regulations implementing this interagency cooperation provision of the Act are codified at 50 CFR 402. Section 7(a)(4) of the Act requires Federal agencies to confer with the Service on any action that is likely to jeopardize the continued existence of a species proposed for listing or result in destruction or adverse modification of proposed critical habitat. If a species is listed subsequently, section 7(a)(2) of the Act requires Federal agencies to ensure that activities they authorize, fund, or carry out are not likely to jeopardize the continued existence of the species or destroy or adversely modify its critical habitat. If a Federal action may affect a listed species or its critical habitat, the responsible Federal agency must enter into formal consultation with the Service.
Federal agency actions within or affecting the species' habitat that may require conference or consultation or both as described in the preceding paragraph include, but are not limited to, projects that will result in removal or degradation of riparian vegetation, altered streamflow or fluvial dynamics, or other habitat-altering activities on Federal lands or as a result of issuance of section 404 CWA permits by the USACE; construction and management of energy and power line rights-of-way by the FERC; construction and maintenance of roads, highways, or bridges by the
Under section 4(d) of the Act, the Service has discretion to issue regulations that we find necessary and advisable to provide for the conservation of threatened species. The Act and its implementing regulations set forth a series of general prohibitions and exceptions that apply to threatened wildlife. The prohibitions of section 9(a)(1) of the Act, as applied to threatened wildlife and codified at 50 CFR 17.31 make it illegal for any person subject to the jurisdiction of the United States to take (which includes harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect; or to attempt any of these) threatened wildlife within the United States or on the high seas. In addition, it is unlawful to import; export; deliver, receive, carry, transport, or ship in interstate or foreign commerce in the course of commercial activity; or sell or offer for sale in interstate or foreign commerce any listed species. It is also illegal to possess, sell, deliver, carry, transport, or ship any such wildlife that has been taken illegally. Certain exceptions apply to employees of the Service, the National Marine Fisheries Service, other Federal land management agencies, and State conservation agencies.
We may issue permits to carry out otherwise prohibited activities involving threatened wildlife under certain circumstances. Regulations governing permits are codified at 50 CFR 17.32. With regard to threatened wildlife, a permit may be issued for the following purposes: For scientific purposes, to enhance the propagation or survival of the species, and for incidental take in connection with otherwise lawful activities. There are also certain statutory exemptions from the prohibitions, which are found in sections 9 and 10 of the Act.
It is our policy, as published in the
Based on the best available information, the following activities may potentially result in a violation of section 9 the Act; this list is not comprehensive: (1) Handling or collecting of the species; (2) destruction/alteration of the species' habitat by discharge of fill material, draining, ditching, tiling, pond construction, stream channelization or diversion, or diversion or alteration of surface or ground water flow; (3) livestock grazing that results in direct or indirect destruction of riparian habitat; (4) activities such as continued presence of cattle and fragmentation of riparian habitat; (5) pesticide applications in violation of label restrictions; and (6) release of biological control agents that modifies or destroys habitat used by the species.
Questions regarding whether specific activities would constitute a violation of section 9 of the Act should be directed to the Sacramento Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT).
National Environmental Policy Act (42 U.S.C. 4321 et seq.)
We have determined that environmental assessments and environmental impact statements, as defined under the authority of the National Environmental Policy Act of 1969 (42 U.S.C. 4321 et seq.), need not be prepared in connection with regulations pursuant to section 4(a) of the Act. We published a notice outlining our reasons for this determination in the
Government-to-Government Relationship With Tribes
In accordance with the President's memorandum of
A complete list of all references cited in this rule is available on the Internet at http://www.regulations.gov or upon request from the Field Supervisor, Sacramento Fish and Wildlife Office (see ADDRESSES).
The primary authors of this final rule are the staff members from the Service's Sacramento Fish and Wildlife Office and the
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and recordkeeping requirements, Transportation.
Accordingly, we amend part 17, subchapter B of chapter I, title 50 of the Code of Federal Regulations, as follows:
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 1531-1544; 4201-4245, unless otherwise noted.
2. Amend SEC 17.11(h) by adding an entry for "Cuckoo, yellow-billed (Western DPS)" to the List of Endangered and Threatened Wildlife in alphabetical order under Birds, to read as follows:
SEC 17.11 Endangered and threatened wildlife.
* * * * *
(h) * * *
Species Common Scientific Historic Vertebrate Status When Critical Special name name Range population listed habitat rules where endangered or threatened * * * * * * * Birds * * * * * * * Cuckoo, Coccyzus U.S.A., Western T 850 NA NA yellow- americanus Canada, DPS: U.S.A. billed Mexico (AZ, CA, CO (western), ID, MT (western), NM (western), NV, OR, TX (western), UT, WA, WY (western)); Canada (British Columbia (southweste rn); Mexico (Baja California, Baja California Sur, Chihuahua, Durango (western), Sinaloa, Sonora) * * * * * * *
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Daniel M. Ashe,
[FR Doc. 2014-23640 Filed 10-2-14;
BILLING CODE 4310-55-P
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