Friday, June 3, 2011

Golden-winged Warbler status enlistment

DEPARTMENT OF THE INTERIOR




Fish and Wildlife Service



50 CFR Part 17



[Docket No. FWS-R3-ES-2011-0028; MO 92210-0-0008]





Endangered and Threatened Wildlife and Plants; 90-Day Finding on

a Petition To List the Golden-Winged Warbler as Endangered or

Threatened



AGENCY: Fish and Wildlife Service, Interior.



ACTION: Notice of petition finding and initiation of status review.



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SUMMARY: We, the U.S. Fish and Wildlife Service, announce a 90-day

finding on a petition to list the golden-winged warbler (Vermivora

chrysoptera) as endangered or threatened under the Endangered Species

Act of 1973, as amended (Act). Based on our review, we find that the

petition presents substantial scientific or commercial information

indicating that listing the golden-winged warbler may be warranted.

Therefore, with the publication of this notice, we are initiating a

review of the status of the species to determine if listing the golden-

winged warbler is warranted. To ensure that this status review is

comprehensive, we are requesting scientific and commercial data and

other information regarding this species. Based on the status review,

we will issue a 12-month finding on the petition, which will address

whether the petitioned action is warranted, as provided in the Act.



DATES: To allow us adequate time to conduct this review, we request

that we receive information on or before August 1, 2011. Please note

that if you are using the Federal eRulemaking Portal (see ADDRESSES

section, below), the deadline for submitting an electronic comment is

11:59 p.m. Eastern Time on this date. After August 1, 2011, you must

submit information directly to the Wisconsin Ecological Services Field

Office (see FOR FURTHER INFORMATION CONTACT section below). Please note

that we might not be able to address or incorporate information that we

receive after the above requested date.



ADDRESSES: You may submit information by one of the following methods:

Federal eRulemaking Portal: http://www.regulations.gov. In the box

that reads ``Enter Keyword or ID,'' enter the Docket number for this

finding, which is FWS-R3-ES-2011-0028. Check the box that reads ``Open

for Comment/Submission,'' and then click the Search



[[Page 31921]]



button. You should then see an icon that reads ``Submit a Comment.''

Please ensure that you have found the correct rulemaking before

submitting your comment.

U.S. mail or hand-delivery: Public Comments Processing, Attn: FWS-

R3-ES-2011-0028; Division of Policy and Directives Management; U.S.

Fish and Wildlife Service; 4401 N. Fairfax Drive, MS 2042-PDM;

Arlington, VA 22203.

We will post all information we receive on http://www.regulations.gov. This generally means that we will post any

personal information you provide us (see the Request for Information

section below for more details).



FOR FURTHER INFORMATION CONTACT: Field Supervisor, Wisconsin Ecological

Services Office, U.S. Fish and Wildlife Office, 2661 Scott Tower Drive,

New Franken, WI 54229-9565; by telephone (920-866-1725); or by

facsimile (920-866-1710). If you use a telecommunications device for

the deaf (TDD), please call the Federal Information Relay Service

(FIRS) at 800-877-8339.



SUPPLEMENTARY INFORMATION:



Request for Information



When we make a finding that a petition presents substantial

information indicating that listing a species may be warranted under

section 4(b)(3)(B) of the Act, we are required to promptly review the

status of the species (status review). For the status review to be

complete and based on the best available scientific and commercial

information, we request information on golden-winged warbler (Vermivora

chrysoptera) from governmental agencies, Native American Tribes, the

scientific community, industry, and any other interested parties. We

seek information on:

(1) The species' biology, range, and population trends, including:

(a) Habitat requirements for feeding, breeding, and sheltering;

(b) Genetics and taxonomy, such as information related to the

hybridization between the golden-winged warbler and the blue-winged

warbler (Vermivora cyanoptera);

(c) Historical and current range, including distribution patterns;

(d) Historical and current population levels, and current and

projected trends; and

(e) Past and ongoing conservation measures for the species, its

habitat, or both.

(2) The factors that are the basis for making a listing

determination for a species under section 4(a) of the Endangered

Species Act of 1973, as amended (Act) (16 U.S.C. 1531 et seq.), which

are:

(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.

If, after the status review, we determine that listing the golden-

winged warbler is warranted, we will propose critical habitat (see

definition in section 3(5)(A) of the Act), under section 4 of the Act,

to the maximum extent prudent and determinable at the time we propose

to list the species. Therefore, within the geographical range currently

occupied by the golden-winged warbler, we request data and information

on:

(1) What may constitute ``physical or biological features essential

to the conservation of the species'';

(2) Where such physical and biological features are currently

found; and

(3) Whether any of these features may require special management

considerations or protection.

In addition, we request data and information on ``specific areas

outside the geographical area occupied by the species'' that are

``essential to the conservation of the species.'' Please provide

specific comments and information as to what, if any, critical habitat

you think we should propose for designation if the species is proposed

for listing, and why such habitat meets the requirements of section 4

of the Act.

Please include sufficient information with your submission (such as

scientific journal articles or other publications) to allow us to

verify any scientific or commercial information you include.

Submissions merely stating support for or opposition to the action

under consideration without providing supporting information, although

noted, will not be considered in making a determination. Section

4(b)(1)(A) of the Act directs that determinations as to whether any

species is an endangered or threatened species must be made ``solely on

the basis of the best scientific and commercial data available.''

You may submit your information concerning this status review by

one of the methods listed in the ADDRESSES section. If you submit

information via http://www.regulations.gov, your entire submission--

including any personal identifying information--will be posted on the

Web site. If you submit a hardcopy that includes personal identifying

information, you may request at the top of your document that we

withhold this personal identifying information from public review.

However, we cannot guarantee that we will be able to do so. We will

post all hardcopy submissions on http://www.regulations.gov.

Information and supporting documentation that we received and used

in preparing this finding is available for you to review at http://www.regulations.gov, or you may make an appointment during normal

business hours at the Wisconsin Ecological Field Office (see FOR

FURTHER INFORMATION CONTACT).



Background



Section 4(b)(3)(A) of the Act (16 U.S.C. 1533(b)(3)(A)) requires

that we make a finding on whether a petition to list, delist, or

reclassify a species presents substantial scientific or commercial

information indicating that the petitioned action may be warranted. We

are to base this finding on information provided in the petition,

supporting information submitted with the petition, and information

otherwise available in our files. To the maximum extent practicable, we

are to make this finding within 90 days of our receipt of the petition

and publish our notice of the finding promptly in the Federal Register.

Our standard for substantial scientific or commercial information

within the Code of Federal Regulations (CFR) with regard to a 90-day

petition finding is ``that amount of information that would lead a

reasonable person to believe that the measure proposed in the petition

may be warranted'' (50 CFR 424.14(b)). If we find that substantial

scientific or commercial information was presented, we are required to

promptly conduct a species status review, which we subsequently

summarize in our 12-month finding.



Petition History



On February 10, 2010, we received a petition, from Anna Sewell,

requesting the golden-winged warbler be listed as endangered or

threatened under the Act. The petition clearly identified itself as

such and included the requisite identification information for the

petitioner, as required by 50 CFR 424.14(a). In an April 16, 2010,

letter to the petitioner Anna Sewell, we responded that we had reviewed

the information presented in the petition and determined that issuing

an emergency regulation temporarily listing the species under section

4(b)(7)



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of the Act was not warranted. This finding addresses the petition.



Previous Federal Action(s)



To date, no Federal actions have been taken with regard to the

golden-winged warbler.



Species Information



The golden-winged warbler (Vermivora chrysoptera) is a neotropical

migrant (breeding in North America and wintering in Central and South

America) belonging to the Order Passeriformes and Family Parulidae

(Sibley 2003, p. 429). It is classified as a discrete species by the

American Ornithologists' Union (AOU 1998, p. 534). The golden-winged

warbler is a small-sized passerine, weighing only 8.8 grams (g) (0.31

ounces (oz)). Total body length is 120.65 millimeters (mm) (4.75 inches

(in)), with a wingspan of 190.5 mm (7.5 in). Diagnostic features

include slate gray plumage on the chest, breast, nape and mantle, with

contrasting yellow patches on the upper wing coverts (sets of small

feathers that cover the upper wing area) and crown. An adult male in

breeding plumage expresses a black throat patch and auriculars (groups

of feathers that cover the sides of a bird's head where the bird's ear

openings are located), with contrasting white supercilium (a plumage

feature on the head) and malar region (around the cheeks). All of those

features are less distinct in females. Both sexes can show a yellow

wash on the mantle extending to secondary coverts (Confer 1992, not

paginated; Sibley 2003, p. 429).

Golden-winged warblers breed across the north-central and eastern

United States, expanding into southeastern Canada. The breeding range

can be thought of as two distinct areas: The northern portion, which

extends into southern Canada (southwestern Quebec, Ontario, Manitoba,

and eastern Saskatchewan) and spreads south into Minnesota, Wisconsin,

and Michigan, and the eastern portion, which includes parts of the

Appalachians (Georgia, North Carolina, and Tennessee) and into

Kentucky, Virginia, West Virginia, Pennsylvania, and New York, with low

numbers in Connecticut, Vermont, and New Hampshire (InfoNatura 2007;

Buehler et al. 2010, p. 8, 31). Breeding locations between the two

distinct areas (Indiana, Ohio, and Illinois, and western New York) hold

low numbers of birds (Sauer et al. 2008, not paginated; Buehler et al.

2006, not paginated). The northern and eastern breeding ranges are

linked by a narrow corridor located in the St. Lawrence River Valley in

north central New York (Buehler et al. 2010, p. 8). Wintering locations

include areas in southern Central America and northern South America

(Buehler et al. 2006, not paginated).

For breeding sites, the golden-winged warbler depends mostly on

early successional habitats. These are habitats that have previously

undergone an amount of disturbance by a natural or human-caused event

that creates a structurally diverse landscape. These habitats can occur

in upland or lowland areas (Buehler et al. 2010, p. 2). Landscapes that

consist of forest edge, shrubs, forests with open canopy, habitats with

grassy openings, and wetlands with scattered trees can be viable

nesting habitats (Rossell et al. 2003, p. 1099; Buehler et al. 2010, p.

10). Breeding sites have been documented in abandoned farmlands,

powerline cuts, recently logged sites, and locations along stream

borders (Confer 1992, not paginated; Service 2009, not paginated).

Habitat tracts of 10-50 hectares (ha) (24-37 acres (ac)) can support

several pairs and are preferred over both smaller and larger areas

(Confer 1992, not paginated). Nest success measures vary throughout

breeding range and within the breeding season; however, rough estimates

are between 40 percent at sites in New York to approximately 75 percent

at sites in North Carolina (Buehler et al. 2007, p. 1440; Buehler et

al. 2010, p. 20-21). Population estimates are approximately 210,000

individuals globally (Partners in Flight PIF Landbird Database).

The diet of the golden-winged warbler consists of small bugs,

larvae, and spiders (Service 2009, not paginated). Golden-winged

warblers can lay three to six eggs, in nests that are low to the ground

and concealed by vegetation (Buehler et al. 2007, p. 1440).



Evaluation of Information for This Finding



Section 4 of the Act (16 U.S.C. 1533) and its implementing

regulations at 50 CFR 424 set forth the procedures for adding a species

to, or removing a species from, 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.

In considering what factors constitute threats, we must look beyond

the exposure of the species to a factor to evaluate whether the species

may respond to the factor in a way that causes actual impacts to the

species. If there is exposure to a factor and the species responds

negatively, the factor may be a threat, and, during the subsequent

status review, we attempt to determine how significant a threat it is.

The threat may be significant if it drives, or contributes to the risk

of, extinction of the species such that the species may warrant listing

as endangered or threatened as those terms are defined in the Act. The

identification of factors that could impact a species negatively may

not be sufficient to compel a finding that substantial information has

been presented suggesting that listing may be warranted. The

information should contain evidence or the reasonable extrapolation

that any factor(s) may be operative threats that act on the species to

the point that the species may meet the definition of endangered or

threatened under the Act.

In making this 90-day finding, we evaluated whether information

regarding threats to the golden-winged warbler, as presented in the

petition and other information available in our files, is substantial,

thereby indicating that the petitioned action may be warranted. Our

evaluation of this information is presented below.



A. The Present or Threatened Destruction, Modification, or Curtailment

of the Species' Habitat or Range.



Information Provided in the Petition

The petition claims that threats causing the present or threatened

destruction, modification, or curtailment of the golden-winged

warbler's habitat or range include habitat loss and modification. The

petition suggests that loss of early successional habitat has

contributed to declining population trends throughout the species'

range (Petition, p. 11; Hunter et al. 2001; NatureServ Explorer).

Golden-winged warblers require early successional landscapes

originating from natural or anthropogenic disturbance. Prior to

European settlement, early successional landscapes occurred via

stochastic events such as natural fires and storms, and through

disturbances to landscapes from other species (for example, bison, elk,

and beaver habitat modifications) (Petition, p. 11; Hamel et al. 2005).

After European settlement in the



[[Page 31923]]



19th century, conversion of natural landscapes to agriculture resulted

in the suppression of natural fires and a decrease in natural land

disturbance. Golden-winged warblers shifted from using naturally

created, early successional breeding habitat, to early successional

habitat created by anthropogenic means (Petition, p. 12; Klaus and

Buehler 2001). Within recent decades there has been a decrease in early

successional habitat due to reforestation of the eastern United States,

development, and changes in agricultural practices. The petition claims

that the golden-winged warbler now breeds within a matrix of human-

developed landscape (urban/suburban development, agriculture, and

reforestation practices), thus leading to its decline in what was

historically viable breeding habitat (Petition, p. 12;

NatureServe2010).

The petition also claims that golden-winged warblers now rely on

human interference to create early successional habitat that consists

of shrubs, open canopy, habitats with forested edge, and/or grassy

patches (Petition, p. 12; Klaus and Buehler 2001). The petition claims

that in the United States, the decline in availability of habitat used

by golden-winged warblers and other early successional habitat-

dependent species (such as grassland birds) is increasingly becoming a

concern (Petition, p. 13; Motzkin and Foster 2004). Although the

petition (Petition, p. 14) states that habitat modification or loss is

the primary obstacle for golden-winged warbler stabilization, Confer et

al. (2003) state that other factors must be involved in population

declines, because in areas where ample suitable habitat exists, such as

in Massachusetts, the warblers have become extirpated;.

Evaluation of Information Provided in the Petition and Available in

Service Files

Information provided by the petitioner and readily available in our

files indicates the golden-winged warbler may be declining rangewide

due to loss, degradation, and modification of early successional

habitat. Forest maturation, land development, wetland destruction and

loss, and lack of natural events that create viable breeding sites

contribute to the reduction of available nesting habitat (Buehler et

al. 2006, p. 1; Buehler et al. 2010, p. 118).

In the north-central breeding range, long-term trends (1966-2007)

estimate populations to be decreasing by 1.4 percent per year (Sauer et

al. 2008, not paginated). In this breeding region, Minnesota,

Wisconsin, and Michigan together hold approximately 69 percent of the

global breeding population of golden-winged warblers (Buehler et al.

2010, p. 31). Long-term trends (1966-2007) for Michigan estimate a

population decline of 8.1 percent per year, with numbers relatively

stable in Minnesota and Wisconsin. In the north-central breeding range,

nests are found in wetland and upland shrub habitats consisting of old

fields and pastures, clearcuts, and regenerating aspen tracts. The

major threats to populations in the north-central breeding range

include habitat loss, wetland drainage, and habitat succession (Buehler

et al. 2010, p. 35).

In Canada (Manitoba, Ontario, Quebec, and Saskatchewan), long-term

Breeding Bird Survey (BBS) data from 1966-2007 (Buehler et al. 2007, p.

144; Sauer et al. 2008, not paginated) indicate a relatively stable

breeding population. This region supports approximately 18.2 percent of

the global breeding population. Limited, short-term data collected over

the last 10 years suggest a 4 percent per year population decline

(Sauer et al. 2008, p. 1). More data are needed to accurately predict

population trends for this region.

The Northeast supports 11 percent of the total global breeding

population (Buehler et al. 2010, p. 74). In this breeding range, long-

term trend information (1966-2007) from BBS data indicates an 8.8

percent per year decline in populations. More recent data from the past

25 years (1980-2007) estimate the same negative trend, at a loss of 6.2

percent per year (Sauer et al. 2008, p.1). Loss of early successional

habitat and fragmentation of existing habitat contribute to the decline

of populations in the Northeast region. Tens of millions of hectares of

habitat has been lost as abandoned farmland passes through early

successional to late successional stages (Confer et al. 2003, p. 142).

This advancement in forest succession is taking place in many areas of

the Northeast. Forest regeneration without regular natural disturbance,

such as fire, results in dense canopy lacking open patches and low

shrub layers. Landscapes with these characteristics are structurally

different than forests that are regularly undergoing natural

disturbance (Buehler et al. 2010, p. 118), and these dense forest

habitats do not support golden-winged warblers. In the Northeast

breeding range specifically, close associations with the blue-winged

warbler (Vermivora cyanoptera) could also be contributing to the

decline of golden-winged warblers. Breeding golden-winged warbler pairs

in the Northeast overlap with blue-winged warbler breeding pairs, and

these interactions can lead to golden-winged warblers either being

pushed out of territories or to hybridization between the two species.

More research is needed to understand if these interspecific

interactions may be a threat to the golden-winged warbler (golden-

winged and blue-winged warbler hybridization is discussed under factor

E (Other natural or manmade factors affecting its continued existence).

In the southeastern breeding range, populations are too low to

estimate decade-long trends; however, long-term trend information

(1966-2007) from BBS data indicate a 7.3 percent decline per year

(Sauer et al. 2008, p. 1). This region only supports 1.4 percent of the

global breeding population (Buehler et al. 2010, p. 58). Research

indicates that the decline of early successional habitat has led to the

extirpation of golden-winged warblers in the southern districts of

Cherokee National Forest, Tennessee (Klaus et al. 2005, p. 232). In

areas of hardwood forests previously occupied by breeding pairs, early

successional habitat has declined because of the occurrence of natural

forest succession without the intervention of forest harvest or natural

disturbance (Klaus et al. 2005, p. 232). Habitat loss may be the cause

of population declines in the southeastern breeding range, because

other potential threats such as blue-winged warbler interactions are

not as common in this region.

Deforestation events have increased in golden-winged warbler

wintering grounds, specifically the montane oak forests in Central and

South America (Buehler et al. 2007, p. 4). The population dynamics of

golden- and blue-winged warblers on wintering grounds lends support to

the assertion that interspecific competition does not appear to be

occurring in this region. Golden-winged warblers occupy areas that are

further south and mostly separated from those of blue-winged warblers,

with limited overlap occurring in northern Panama, Costa Rica,

Honduras, Nicaragua, and Guatemala (Confer 1992, not paginated; Buehler

et al. 2010, p. 120). Although it is unclear if the loss of

overwintering habitat affects survival, overall golden-winged warbler

population declines may be related. Potential threats to the species on

wintering grounds need to be examined to determine if changes in

wintering habitat are limiting to golden-winged warbler population

viability.

The degradation of migratory stopover sites could impact fitness of

individuals, or more directly cause mortality



[[Page 31924]]



(Buehler et al. 2010, p. 120). Other anthropogenic factors could impact

individuals along migratory routes or at stopover sites. One report

compiled data from 47 studies that monitored bird strikes at

communication towers and found that golden-winged warbler mortality was

identified at 15 towers, which accounted for 542 individuals (Shire et

al. 2000, p.8).

BBS data indicate that the golden-winged warblers' breeding range

has been shifting for the last 150 years and population numbers have

declined (Confer et al. 2003, p. 142; Sauer et al. 2008, p. 1; Buehler

et al. 2010, p. 24). Breeding populations in other States may become

extirpated (Connecticut, South Carolina, Georgia, Indiana, Illinois,

and Rhode Island) (Confer 1992, not paginated; Buehler et al. 2010, p.

25) and, already, the golden-winged warbler has not been verified to be

breeding in Massachusetts (USGS North American Breeding Bird Atlas

Explorer).

Golden-winged warblers require specific habitat characteristics

found in early successional landscapes for nesting, and loss of this

habitat may continue to reduce populations by limiting fecundity and,

therefore, reproductive success, leading to population declines. In

general, we expect golden-winged warbler populations to continue to

decline, as a response to the reduction in breeding areas due to

destruction, modification, and curtailment of early successional

habitats. Loss of overwintering habitat and degradation of migratory

stopover sites may also contribute to continuing population declines by

reducing survival or reducing overall fitness, which can translate to

reduced fecundity.

Summary of Factor A

In summary, the petition and information in our files identifies

the loss of early successional habitat by changes in agricultural

practices, forest maturation, land development, wetland destruction and

loss, and lack of natural disturbance events as potential threats to

the golden-winged warbler. Furthermore, winter habitat is affected by

increasing deforestation and migrating individuals are impacted by the

increasing number of communication towers. Therefore, we find that the

information provided in the petition, as well as other information

readily available in our files, presents substantial scientific or

commercial information to indicate that the golden-winged warbler may

warrant listing due to the present or threatened destruction,

modification, or curtailment of the species' habitat or range.



B. Overutilization for Commercial, Recreational, Scientific, or

Educational Purposes.



Information Provided in the Petition

The petition did not present any information with respect to Factor

B.

Evaluation of Information Provided in the Petition and Available in

Service Files

The information in our files does not indicate any threat to

golden-winged warbler due to overutilization for commercial,

recreational, scientific, or educational purposes. Therefore, we find

that the petition and information readily available in our files does

not provide substantial scientific or commercial information to

indicate that the overutilization for commercial, recreational,

scientific, or educational purposes may present a threat to the golden-

winged warbler such that the petitioned action may be warranted.

However, we will further investigate the potential threat of

overutilization for commercial, recreational, scientific, or

educational purposes in our status review for this species.



C. Disease or Predation



Information Provided in the Petition

The petition did not present any information with respect to Factor

C.

Evaluation of Information Provided in the Petition and Available in

Service Files

Our files indicate that, although nest predation may be a leading

cause of nest loss for golden-winged warblers, there is not enough data

indicating that nest predation rates are limiting factors in population

declines (Buehler et al. 2010, p. 125). Therefore, the information in

our files does not indicate any threat to golden-winged warblers due to

disease or predation. We find that the petition and information readily

available in our files do not provide substantial scientific or

commercial information to indicate that disease or predation may

present a threat to the golden-winged warbler such that the petitioned

action may be warranted. However, we will further investigate the

potential threat of disease or predation in our status review for this

species.



D. The Inadequacy of Existing Regulatory Mechanisms



Information Provided in the Petition

The petition claims that the only way to ensure protection for the

golden-winged warbler is to mandate Federal protection across the

species' entire North and South America range (Petition, pp. 22-23).

The petition suggests that existing regulatory mechanisms do not

adequately protect the golden-winged warbler. State regulations provide

the species protection from only the sale or take of individuals; in

addition, State regulations are insignificant because they protect the

species at localized areas only, versus the entire range, and do not

address habitat protection or conservation (Petition, pp. 16-23).

Evaluation of Information Provided in the Petition and Available in

Service Files

In Canada, golden-winged warblers are protected under the Migratory

Bird Convention Act of 1916 and by the Schedule One of Canada's Species

at Risk Act. The Committee of the Status of Endangered Wildlife in

Canada (COSEWIC) lists the bird as threatened in Quebec, Ontario, and

Manitoba. In the United States, under the Migratory Bird Treaty Act of

1918, as amended, it is unlawful to take, capture, kill, or possess

migratory birds, their nests, eggs, and young. These protections extend

to the golden-winged warbler. The Service has identified the golden-

winged warbler nationally as a Bird of Conservation Concern, which is a

designation assigned to the species by the Division of Migratory Bird

Management. This designation indicates that the species is one which,

without additional conservation actions, is likely to become a

candidate for listing under the Act.

The Service also identifies the species as a bird of management

concern at the Bird Conservation Region (BCR) scale (developed by the

North American Bird Conservation Initiative) in regions 12 (Boreal

Hardwood Transition Zones), 13 (Lower Great Lakes/St. Lawrence Plain),

23 (Prairie Hardwood Transitions Zones), and 28 (Appalachian Mountains)

(Service 2008, pp. 28, 29, 39, 44). Partners in Flight ranks the

golden-winged warbler as a Watch List Species in need of immediate

management action (Buehler et al. 2010, p. 127 cited from Rich et al.

2004). The golden-winged warbler is listed as a Species of Global

Concern on the Audubon Society's species watch list (The National

Audubon Society, not paginated). The International Union for

Conservation of Nature (IUCN) lists golden-winged warblers as Near

Threatened on their Global Continental Conservation Status list

(BirdLife International 2008). These various classifications, however,

are not regulatory in nature.



[[Page 31925]]



The golden-winged warbler is State-listed as threatened,

endangered, or of special concern in some areas of its range.

Regulatory protections for State-listed species vary by individual

States, but in general, State-listed species do not receive the same

level of protection, especially with regard to habitat loss, afforded

to Federally listed species. The Service is leading a cooperative

effort with Federal and State agencies, researchers, universities and

other nongovernment organizations to determine the extent of threats to

the golden-winged warbler population. Developed in 2003, the Golden

Winged Warbler Working Group consists of Federal, State, and nonprofit

entities. The Working Group prioritizes research and monitoring

activities, investigates hybridization range and species genetics,

develops habitat classification measures and management priorities, and

works with the Natural Resource Conservation Service (NRCS, U.S.

Department of Agriculture) to integrate species-specific management

into legislation such as the Farm Bill (Buehler et al. 2007, p. 1442).

The working group conducts a variety of conservation efforts and

research throughout the species' range. These collaborative efforts

were initiated separately from the petition for listing this species

under the Act, and solely because of the interest of the cooperating

organizations in improving the status of this species, which is widely

recognized as a species of conservation concern.

Summary of Factor D

The petition and information in our files suggest that individual

State-level protections are not adequately protecting the warbler, as

evidenced by declining population trends in all breeding areas and

declining habitat trends on the wintering grounds. In addition, the

existing regulatory mechanisms do not provide habitat conservation or

protection measures, nor do they directly address management incentives

for the golden-winged warbler. The formation of the Golden Winged

Warbler Working Group is leading the development of conservation

initiatives; however, this group does not have authority to implement

wide-scale population-level protection. Declining population trends in

all breeding areas, as well as declining habitat trends on the

wintering grounds of golden-winged warbler, continue, and existing

legislation does not protect the golden-winged warbler or its habitat

throughout the species' range. Therefore, we find that the information

provided in the petition, as well as other information readily

available in our files, presents substantial scientific or commercial

information to indicate that the golden-winged warbler may warrant

listing due to the inadequacy of existing regulatory mechanisms.



E. Other Natural or Manmade Factors Affecting Its Continued Existence.



Interactions With Blue-Winged Warbler

Information Provided in the Petition

The petition claims that golden-winged warblers are being displaced

by the expansion of blue-winged warblers, resulting in golden-winged

warblers being pushed north into Ontario and west into Minnesota

(Petition, p. 15; Hamel et al. 2005). The expansion of blue-winged

warblers into golden-winged warblers' habitat may be correlated with

loss of early successional habitat (Petition, p. 15; NatureServe 2010).

The range of the golden-winged and blue-winged warblers overlap

considerably, and data from one study found that golden-winged warblers

nesting near blue-winged warblers laid fewer eggs (Petition, p. 15;

Confer et al. 2003, p. 141).

Evaluation of Information Provided in the Petition and Available in

Service Files

Data from the last 150 years document the replacement of golden-

winged warblers with blue-winged warblers in areas of the Northeast

(Buehler et al. 2010, p. 75). The expansion of blue-winged warblers may

result in the displacement of golden-winged warblers, a decrease in

productivity, or an increase in hybridization events (Confer et al.

2003, p. 141; Buehler et al. 2010, p. 121).

The golden-winged warbler is closely related to the blue-winged

warbler, and interbreeding between the two species occurs, producing

fertile young (Confer 1992, not paginated; Buehler et al. 2010, p. 5).

The two hybrids that can result from the cross-mating of the two

species are Brewster's warbler and Lawrence's warbler. The Brewster's

warbler is a first-generation hybrid, meaning a cross between golden-

winged and blue-winged parents. It holds the dominate traits of both

parents (white ventral plumage of the golden-winged warbler but overall

coloration of the blue-winged warbler). Brewster's hybrids can back-

cross with golden-winged or blue-winged warblers to produce viable

offspring (Gough and Sauer 1997, not paginated). The Lawrence's warbler

is a cross between a Brewster's warbler and a golden-winged warbler, or

a Brewster's warbler and a blue-winged warbler. The Lawrence's warbler

displays the recessive traits (feather coloration of the golden-winged,

with yellow plumage of the blue-winged) (Gough and Sauer 1997, not

paginated; Buehler et al. 2010, p. 5).

The population-level impacts of interactions between golden-winged

and blue-winged warblers, and variables contributing to hybridization

events, are unclear. In two hybridization zones, nest success rates for

the golden-winged warbler were lower in New York at sites that had

documentation of species hybridization compared to sites in North

Carolina that had no evidence of hybridization (Klaus and Buehler 2001,

p. 300). This suggests that in areas where the two species occur

together, reproductive efforts of golden-winged warblers may be

suppressed due to hybridization. However, in New York there are areas

of overlap where the two species are sympatric and co-exist without

detected impacts to golden-winged warbler productivity (Confer and

Larkin 1998, p. 213).

The degree of hybridization may vary within different geographic

locations. For example, interspecific interactions between blue-winged

and golden-winged warblers may be more pronounced in the northeastern

United States, where populations overlap considerably (Buheler et al.

2010, p. 118). In upland areas of New York and Pennsylvania, golden-

winged warblers might be limited by habitat loss in addition to blue-

winged warbler hybridization, while populations in North Carolina may

be limited only by habitat loss (Buehler et al. 2007, p. 1440). In some

areas of the southeastern United States, the golden-winged warbler

population has declined in the absence of blue-winged warblers (Buheler

et al. 2010, p. 121). Therefore, other factors likely contribute to

declines of golden-winged warbler populations in the southeastern

breeding range.

More research is needed to fully understand the possible effects of

hybridization on the golden-winged warbler. The information in the

petition and in Service files provides limited data on golden-winged

and blue-winged warbler interactions. We find the information provided

in the petition discusses one possible threat, the possible reduction

of golden-winged warbler productivity due to blue-winged warblers

occupying golden-winged warbler breeding sites. Information in Service

files indicates that interspecific interactions, such as species

hybridization, may be a threat to the golden-winged warbler, especially

in



[[Page 31926]]



specific geographic locations. Both the petition and Service files

recognize that blue-winged warblers are expanding into golden-winged

warblers' range and that this expansion could be correlated with the

loss of early successional habitat. Although the effects of

interspecific interactions (reduced breeding productivity or

hybridization) between the blue-winged and golden-winged warbler remain

unclear, we find that the information provided in the petition, as well

as other information readily available in our files, presents

substantial scientific or commercial information to indicate that the

golden-winged warbler may warrant listing due to other natural or

manmade factors affecting the species' continued existence due to these

factors.

Brown-headed Cowbird Nest Parasitism

Information Provided in the Petition

The petition states that brown-headed cowbirds (Molothrus ater) are

parasitizing golden-winged warbler nests, with evidence suggesting that

the rate of parasitism reduces fledgling success (Petition, p. 15). The

study cited in the petition was conducted in New York and found a 50

percent loss in fledgling success in nests with brown-headed cowbird

eggs. However, the small sample size of nests (34 nonparasitized nests

and 7 parasitized nests) may lead to statistical error (Confer et al.

2003, p. 141). This study found that fledgling rate in nonparasitized

nests was high (68 percent), while fledgling rate in parasitized nests

was low (32 percent), and that this difference is enough to warrant

concern about brown-headed cowbird parasitism limiting golden-winged

warbler fledgling success (Confer et al. 2003, p. 141). The petition

concludes that nest parasitism, coupled with other factors, leads to

reduced fledgling success (Petition, p. 15).

Evaluation of Information Provided in the Petition and Available in

Service Files

The rate of cowbird parasitism varies within the range of golden-

winged warblers. Golden-winged warbler nests, especially in

agricultural landscapes, experience moderate rates of parasitism

(Confer 1992, not paginated). In a sample size of nests found in the

eastern United States, central Michigan, central New York, and eastern

New Jersey, 11 of 113 nests were parasitized (Coker and Confer 1990, p.

551). In nests found in New York, from 1988 to 1994, 30 percent had at

least one cowbird egg or chick, which reduced fledgling success by 17

percent (Confer et al. 2003, p. 138). Although brown-headed cowbirds

were present, cowbird parasitism was not recorded in nests of golden-

winged warblers in areas of Tennessee and North Carolina (Klaus and

Buehler 2001, p. 29) and was not apparently impacting golden-winged

populations in West Virginia or Ontario (Buehler et al. 2010, p. 23).

At breeding sites in north central New York, cowbird parasitism was

correlated with a reduction in incubated eggs and a reduction in the

proportion of incubated eggs that hatched; however, parasitism did not

significantly affect nestling success rate (Confer et al. 2003, p.

138).

Although there is evidence indicating golden-winged warblers are

susceptible to brown-headed cowbird parasitism, it has not yet been

determined if brown-headed cowbird parasitism has a substantial impact

on golden-winged warbler nest success rates throughout the species'

breeding range. Brown-headed cowbird parasitism may be a greater

concern for warblers nesting in the northeast United States, compared

to warblers in the north central breeding range.

We find that, based on information in the petition, as well as

other information readily available in our files, we are unsure of the

impact cowbird parasitism may have on the golden-winged warbler.

However, we will further investigate the potential impacts of cowbird

parasitism in our 12-month status review.



Finding



On the basis of our analysis under section 4(b)(3)(A) of the Act,

we determine that the petition presents substantial scientific or

commercial information indicating that listing the golden-winged

warbler throughout its entire range may be warranted. This finding is

based on information provided under Factors A (present or threatened

destruction, modification, or curtailment of the species' habitat or

range), D (the inadequacy of existing regulatory mechanisms), and E

(other natural or manmade factors affecting the species' continued

existence). Specifically, we find that the following may pose threats

to the golden-winged warbler throughout all or a significant portion of

its range, such that the petitioned action may be warranted: Habitat

modification and loss of early successional habitat (Factor A);

inadequacy of existing regulatory mechanisms (because existing

regulations only provide protection from the sale or take of

individuals at localized areas, rather than the entire range, and do

not address habitat protection or conservation) (Factor D); and

interactions with blue-winged warblers (Factor E). We determine that

the information provided under Factors B (overutilization for

commercial, recreational, scientific or educational purposes) and C

(disease or predation) is not substantial.

Because we have found that the petition presents substantial

information indicating that listing the golden-winged warbler may be

warranted, we are initiating a status review to determine whether

listing the golden-winged warbler under the Act is warranted.

The ``substantial information'' standard for a 90-day finding

differs from the Act's ``best scientific and commercial data'' standard

that applies to a status review to determine whether a petitioned

action is warranted. A 90-day finding does not constitute a status

review under the Act. In a 12-month finding, we will determine whether

a petitioned action is warranted after we have completed a thorough

status review of the species, which is conducted following a

substantial 90-day finding. Because the Act's standards for 90-day and

12-month findings are different, as described above, a substantial 90-

day finding does not mean that the 12-month finding will result in a

warranted finding.



References Cited



A complete list of references cited is available on the Internet at

http://www.regulations.gov and upon request from the Wisconsin

Ecological Services Office (see FOR FURTHER INFORMATION CONTACT).



Author



The primary authors of this notice are the staff members of the

Wisconsin Ecological Services Office (see FOR FURTHER INFORMATION

CONTACT).



Authority: The authority for this action is the Endangered

Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).



Dated: May 4, 2011.

Rowan W. Gould,

Acting Director, U.S. Fish and Wildlife Service.

[FR Doc. 2011-13731 Filed 6-1-11; 8:45 am]

BILLING CODE 4310-55-P