Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To List the Golden-Winged Warbler as Endangered or Threatened, 31920-31926 [2011-13731]
Download as PDF
<![CDATA[
srobinson on DSK4SPTVN1PROD with PROPOSALS
31920
Federal Register / Vol. 76, No. 106 / Thursday, June 2, 2011 / Proposed Rules
controlling Utah prairie dogs are limited
to activities associated with
translocation efforts by trained and
permitted individuals complying with
current Service-approved guidance,
trapping intended for lethal removal,
and shooting. Actions intended to
drown or poison Utah prairie dogs are
prohibited. Under the provisions of
paragraph (g)(2) of this section and
permitted by the Utah Division of
Wildlife Resources, direct or intentional
take is limited to agricultural land and
private property near conservation land
as follows:
(i) Agricultural land. (A) Take may be
permitted only on agricultural land
being physically or economically
affected by Utah prairie dogs, and only
when the spring count on the
agricultural lands is five or more
individuals; and
(B) The land must:
(1) Meet the general classification of
irrigated, dryland, grazing land, orchard,
or meadow;
(2) Be capable of producing crops or
forage;
(3) Be at least 2 contiguous ha (5
contiguous ac) in area (smaller parcels
may qualify where devoted to
agricultural use in conjunction with
other eligible acreage under identical
legal ownership);
(4) Be managed in such a way that
there is a reasonable expectation of
profit;
(5) Have been devoted to agricultural
use for at least 2 successive years
immediately preceding the year in
which application is made; and
(6) Meet State average annual (peracre) production requirements.
(ii) Private property near conservation
land. (A) Take may be permitted on
private properties within 0.8 km (0.5
mi) of Utah prairie dog conservation
land.
(B) Conservation lands are defined as
non-Federal areas set aside for the
preservation of Utah prairie dogs and
are managed specifically or primarily
toward that purpose. Conservation lands
may include, but are not limited to,
properties set aside as conservation
banks, fee- title purchased properties,
properties under conservation
easements, and properties subject to a
safe harbor agreement (see § 17.22.).
Conservation lands do not include
Federal lands.
(iii) Permitted take on agricultural
lands and private property near
conservation land. (A) The Utah
Division of Wildlife Resources will
ensure that permitted take does not
exceed 10 percent of the estimated
rangewide population annually.
VerDate Mar<15>2010
16:38 Jun 01, 2011
Jkt 223001
(B) On agricultural lands, the Utah
Division of Wildlife Resources will limit
permitted take to 7 percent of the
estimated annual rangewide population
and will limit within-colony take to
one-half of a colony’s estimated annual
production.
(C) In setting take limits on properties
neighboring conservation lands, the
Utah Division of Wildlife Resources will
consider the amount of take that occurs
on agricultural lands. The State will
restrict the remaining permitted take
(the amount that would bring the total
take up to 10 percent of the estimated
annual rangewide population) on
properties neighboring conservation
lands to animals in excess of the
baseline population. The baseline
population of neighboring lands is the
highest estimated population on that
property during the 5 years prior to
establishment of the conservation
property.
(D) Translocated Utah prairie dogs
will count toward the take limits in
paragraphs (g)(3)(iii)(B) and (g)(3)(iii)(C)
of this section.
(4) Incidental take. Utah prairie dogs
may be taken when take is incidental to
otherwise-legal activities associated
with standard agricultural practices on
agricultural lands. These mortalities are
in addition to the direct or intentional
take provisions in paragraphs (g)(2) and
(g)(3) of this section. Acceptable
practices include plowing to depths that
do not exceed 46 cm (18 in.), discing,
harrowing, irrigating crops, mowing,
harvesting, and bailing, as long as the
activities are not intended to eradicate
Utah prairie dogs.
(5) If the Service receives evidence
that take pursuant to paragraphs (g)(2)
through (g)(4) of this section is having
an effect that is inconsistent with the
conservation of the Utah prairie dog, the
Service may immediately prohibit or
restrict such take as appropriate for the
conservation of the species.
*
*
*
*
*
Dated: May 18, 2011.
Jane Lyder,
Acting Assistant Secretary for Fish and
Wildlife and Parks.
[FR Doc. 2011–13684 Filed 6–1–11; 8:45 am]
BILLING CODE 4310–55–P
PO 00000
Frm 00037
Fmt 4702
Sfmt 4702
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
Fish and Wildlife Service,
Interior.
ACTION: Notice of petition finding and
initiation of status review.
AGENCY:
We, the U.S. Fish and
Wildlife Service, announce a 90-day
finding on a petition to list the goldenwinged 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: https://
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
SUMMARY:
E:\FR\FM\02JNP1.SGM
02JNP1
Federal Register / Vol. 76, No. 106 / Thursday, June 2, 2011 / Proposed Rules
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 https://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:
srobinson on DSK4SPTVN1PROD with PROPOSALS
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
VerDate Mar<15>2010
16:38 Jun 01, 2011
Jkt 223001
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 goldenwinged 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 goldenwinged 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
https://www.regulations.gov, your entire
submission—including any personal
identifying information—will be posted
on the Web site. If you submit a
PO 00000
Frm 00038
Fmt 4702
Sfmt 4702
31921
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 https://
www.regulations.gov.
Information and supporting
documentation that we received and
used in preparing this finding is
available for you to review at https://
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 12month 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)
E:\FR\FM\02JNP1.SGM
02JNP1
31922
Federal Register / Vol. 76, No. 106 / Thursday, June 2, 2011 / Proposed Rules
of the Act was not warranted. This
finding addresses the petition.
srobinson on DSK4SPTVN1PROD with PROPOSALS
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.
VerDate Mar<15>2010
16:38 Jun 01, 2011
Jkt 223001
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
PO 00000
Frm 00039
Fmt 4702
Sfmt 4702
(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
E:\FR\FM\02JNP1.SGM
02JNP1
Federal Register / Vol. 76, No. 106 / Thursday, June 2, 2011 / Proposed Rules
srobinson on DSK4SPTVN1PROD with PROPOSALS
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 humandeveloped 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 goldenwinged 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
VerDate Mar<15>2010
16:38 Jun 01, 2011
Jkt 223001
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 northcentral 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, shortterm 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
PO 00000
Frm 00040
Fmt 4702
Sfmt 4702
31923
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 goldenwinged 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 goldenwinged warbler population viability.
The degradation of migratory stopover
sites could impact fitness of individuals,
or more directly cause mortality
E:\FR\FM\02JNP1.SGM
02JNP1
31924
Federal Register / Vol. 76, No. 106 / Thursday, June 2, 2011 / Proposed Rules
(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 goldenwinged 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.
srobinson on DSK4SPTVN1PROD with PROPOSALS
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
VerDate Mar<15>2010
16:38 Jun 01, 2011
Jkt 223001
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 goldenwinged warbler is to mandate Federal
PO 00000
Frm 00041
Fmt 4702
Sfmt 4702
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 goldenwinged 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.
E:\FR\FM\02JNP1.SGM
02JNP1
Federal Register / Vol. 76, No. 106 / Thursday, June 2, 2011 / Proposed Rules
srobinson on DSK4SPTVN1PROD with PROPOSALS
The golden-winged warbler is Statelisted as threatened, endangered, or of
special concern in some areas of its
range. Regulatory protections for Statelisted 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 goldenwinged 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 goldenwinged warbler or its habitat throughout
the species’ range. Therefore, we find
that the information provided in the
VerDate Mar<15>2010
16:38 Jun 01, 2011
Jkt 223001
petition, as well as other information
readily available in our files, presents
substantial scientific or commercial
information to indicate that the goldenwinged 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 goldenwinged 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 goldenwinged 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 goldenwinged warblers nesting near bluewinged 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 bluewinged 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 bluewinged parents. It holds the dominate
traits of both parents (white ventral
plumage of the golden-winged warbler
but overall coloration of the bluewinged warbler). Brewster’s hybrids can
back-cross with golden-winged or bluewinged 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
PO 00000
Frm 00042
Fmt 4702
Sfmt 4702
31925
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 goldenwinged 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 goldenwinged 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
E:\FR\FM\02JNP1.SGM
02JNP1
31926
Federal Register / Vol. 76, No. 106 / Thursday, June 2, 2011 / Proposed Rules
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 goldenwinged 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 goldenwinged 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
srobinson on DSK4SPTVN1PROD with PROPOSALS
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 brownheaded 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 goldenwinged 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
VerDate Mar<15>2010
16:38 Jun 01, 2011
Jkt 223001
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 brownheaded cowbird parasitism has a
substantial impact on golden-winged
warbler nest success rates throughout
the species’ breeding range. Brownheaded 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 12month status review.
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 90day 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 90day 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.
Finding
References Cited
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);
A complete list of references cited is
available on the Internet at https://
www.regulations.gov and upon request
from the Wisconsin Ecological Services
Office (see FOR FURTHER INFORMATION
CONTACT).
PO 00000
Frm 00043
Fmt 4702
Sfmt 9990
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
E:\FR\FM\02JNP1.SGM
02JNP1
]]>Agencies
[Federal Register Volume 76, Number 106 (Thursday, June 2, 2011)]
[Proposed Rules]
[Pages 31920-31926]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-13731]
-----------------------------------------------------------------------
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.
-----------------------------------------------------------------------
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: https://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 https://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 https://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 https://www.regulations.gov.
Information and supporting documentation that we received and used
in preparing this finding is available for you to review at https://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)
[[Page 31922]]
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
https://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
