# Endangered and Threatened Wildlife and Plants; Listing Taylor's Checkerspot Butterfly and Streaked Horned Lark and Designation of Critical Habitat

> Briefs, arguments, decisions, and more.

URL: https://www.frixlaw.com/law-library/documents/fr%3A2012-24465

## Record

- **Collection:** Federal Register
- **Document type:** Proposed Rule
- **Published:** October 11, 2012
- **Citation:** 77 FR 61938

## Text

DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[FWS-R1-ES-2012-0080; 4500030113]
RIN 1018-AY18
Endangered and Threatened Wildlife and Plants; Listing Taylor's Checkerspot Butterfly and Streaked Horned Lark and Designation of Critical Habitat

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Proposed rule.

SUMMARY:

We, the U.S. Fish and Wildlife Service, propose to list the Taylor's checkerspot butterfly as an endangered species, and to list the streaked horned lark as a threatened species under the Endangered Species Act of 1973, as amended (Act). We additionally propose to designate critical habitat for these species. These determinations fulfill our obligations under a settlement agreement. These are proposed regulations, and if finalized, the effect of these regulations will be to add these species to the List of Endangered and Threatened Wildlife and to designate critical habitat under the Endangered Species Act.

DATES:

We will accept comments received or postmarked on or before December 10, 2012. We must receive requests for public hearings, in writing, at the address shown in
FOR FURTHER INFORMATION CONTACT
by November 26, 2012.

ADDRESSES:

You may submit comments by one of the following methods:

(1)
Electronically:
Go to the Federal eRulemaking Portal:
http://www.regulations.gov.
In the Search box, enter Docket No. FWS-R1-ES-2012-0080, which is the docket number for this rulemaking. You may submit a comment by clicking on “Comment Now!”.

(2)
By hard copy:
Submit by U.S. mail or hand-delivery to: Public Comments Processing, Attn: FWS-R1-ES-2012-0080; Division of Policy and Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, MS 2042-PDM; Arlington, VA 22203.

We request that you send comments only by the methods described above. We will post all comments on
http://www.regulations.gov.
This generally means that we will post any personal information you provide us (see the Public Comments section below for more information).

The coordinates or plot points or both from which the critical habitat maps are generated are included in the administrative record for this rulemaking and are available at
http://www.fws.gov/wafwo/,

www.regulations.gov
at Docket No. [FWS-R1-ES-2012-0080], and at the Washington Fish and Wildlife Office (see
FOR FURTHER INFORMATION CONTACT
). Any additional tools or supporting information that we may develop for this rulemaking will also be available at the Fish and Wildlife Service Web site and Field Office set out above, and may also be included in the preamble and/or at
www.regulations.gov
.

FOR FURTHER INFORMATION CONTACT:

Ken S. Berg, Manager, Washington Fish and Wildlife Office, 510 Desmond Drive, Lacey, WA 98503, by telephone (360) 753-9440, or by facsimile (360) 534-9331. Persons who use a telecommunications device for the deaf (TDD) may call the Federal Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

Why we need to publish a rule.
Under the Endangered Species Act (Act), a species may warrant protection through listing if it is an endangered or threatened species throughout all or a significant portion of its range. The species addressed in these proposed rules are candidates for listing and, by virtue of a settlement agreement, we must make a determination as to their present status under the Act. These status changes can only be done by issuing a rulemaking. The table below summarizes our determination for each of these candidate species:

Species
Present range
Status

Taylor's checkerspot butterfly,
Euphydryas editha taylori

British Columbia, Canada; Clallam, Pierce, and Thurston Counties, WA; and Benton County, OR
Proposed Endangered.

Streaked horned lark,
Eremophila alpestris strigata

Grays Harbor, Mason, Pacific, Pierce, Thurston, Cowlitz, and Wahkiakum Counties, WA; Benton, Clackamas, Clatsop, Columbia, Lane, Linn, Marion, Multnomah, Polk, Washington, and Yamhill Counties, OR
Proposed Threatened.

The basis for our action.
Under the Endangered Species Act, we may determine that a species is an endangered or threatened species based on any of five factors: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; or (E) other natural or manmade factors affecting its continued existence.

For those species for which we are proposing listing, we have determined that these species are impacted by one or more of the following factors to the extent that the species meets the definition of an endangered or threatened species under the Act:

• Habitat loss through conversion and degradation of habitat, particularly from agricultural and urban development, successional changes to grassland habitat, military training, and the spread of invasive plants;

• Predation;

• Inadequate existing regulatory mechanisms that allow significant threats such as habitat loss;

• Other natural or manmade factors, including low genetic diversity, small or isolated populations, low reproductive success, and declining population sizes;

• Aircraft strikes and training at airports; and

• Pesticide use or control as a pest species.

In this rule we propose to designate critical habitat for these species
. We are proposing to designate critical habitat for the Taylor's checkerspot butterfly and streaked horned lark in Washington and Oregon as follows:

• Approximately 6,875 acres (ac) (2,782 hectares (ha)) are proposed for designation as critical habitat for the Taylor's checkerspot butterfly.

• Approximately 12,159 ac (4,920 ha) are proposed for designation as critical habitat for the streaked horned lark.

The basis for our action.
Under the Endangered Species Act, we are required to designate critical habitat for any species that is determined to be endangered or threatened. We are required to base the designation on the best available scientific data after taking into consideration economic, national security, and other relevant impacts. An area may be excluded from the final designation of critical habitat if the

benefits of exclusion outweigh the benefits of designation, unless the exclusion will result in the extinction of the species.

We are proposing to promulgate special rules.
We are considering whether to exempt from the Act's take prohibitions (at section 9), existing maintenance activities and agricultural practices located on private and Tribal lands where the streaked horned lark occurs. The intent of this special rule would be to increase support for the conservation of the streaked horned lark and provide an incentive for continued management activities that benefit this species and its habitat.

We are preparing an economic analysis.
To ensure that we fully consider the economic impacts, we are preparing a draft economic analysis of the proposed designations of critical habitat. We will publish an announcement and seek public comments on the draft economic analysis when it is completed.

We will seek peer review.
We are seeking comments from knowledgeable individuals with scientific expertise to review our technical assumptions, analysis of the best available science, and application of that science or to provide any additional scientific information to improve these proposed rules. Because we will consider all comments and information received during the comment period, our final determinations may differ from this proposal.

We are seeking public comment on this proposed rule.
Anyone is welcome to comment on our proposal or provide additional information on the proposal that we can use in making a final determination on the status of this species. Please submit your comments and materials concerning this proposed rule by one of the methods listed in the
ADDRESSES
section. Within 1 year following the publication of this proposal, we will publish in the
Federal Register
a final determination concerning the listing of the species and the designation of its critical habitat or withdraw the proposal if new information is provided that supports that decision.

Information Requested

We intend that any final action resulting from this proposed rule will be based on the best scientific and commercial data available and be as accurate and as effective as possible. Therefore, we request comments or information from the public, other concerned governmental agencies, Native American tribes, the scientific community, industry, or any other interested parties concerning this proposed rule. We particularly seek comments concerning:

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

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

(b) Genetics and taxonomy;

(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 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.

(3) Biological, commercial trade, or other relevant data concerning any threats (or lack thereof) to this species and existing regulations that may be addressing those threats;

(4) Additional information concerning the historical and current status, range, distribution, and population size of this species, including the locations of any additional populations of this species;

(5) Any information on the biological or ecological requirements of the species, and ongoing conservation measures for the species and its habitat;

(6) The reasons why we should or should not designate areas as “critical habitat” under section 4 of the Act (16 U.S.C. 1531
et seq.
), including whether there are threats to any of these species from human activity, the degree of which can be expected to increase due to the designation, and whether that increase in threat outweighs the benefit of designation such that the designation of critical habitat may not be prudent.

(7) Specific information on:

(a) The amount and distribution of habitat for the Taylor's checkerspot butterfly and streaked horned lark;

(b) What areas that were occupied at the time of listing (or are currently occupied) and that contain features essential to the conservation of the species should be included in the designation and why;

(c) Special management considerations or protection that may be needed in critical habitat areas we are proposing; and

(d) What areas not occupied at the time of listing are essential for the conservation of the species and why.

(8) Land use designations and current or planned activities in the subject areas and their possible impacts on proposed critical habitat.

(9) Information on the projected and reasonably likely impacts of climate change on the Taylor's checkerspot butterfly and streaked horned lark, and on proposed critical habitat.

(10) Any probable economic, national security, or other relevant impacts of designating any area that may be included in the final designation; in particular, any impacts on small entities or families, and the benefits of including or excluding areas that exhibit these impacts.

(11) Whether any specific areas we are proposing for critical habitat designation should be considered for exclusion under section 4(b)(2) of the Act, and whether the benefits of potentially excluding any specific area outweigh the benefits of including that area under section 4(b)(2) of the Act.

(12) Additional information pertaining to the promulgation of a special rule to exempt take of the streaked horned lark on civilian airports, agricultural fields, and tribal lands under section 4(d) of the Act.

(13) Whether any populations of the streaked horned lark should be considered separately for listing as a distinct population segment (DPS), and if so, the justification for how that population meets the criteria for a DPS under the Service's Policy Regarding the Recognition of Distinct Vertebrate Population Segments under the Endangered Species Act (61 FR 4722, February 7, 1996).

(14) Whether we could improve or modify our approach to designating critical habitat in any way to provide for greater public participation and understanding, or to better accommodate public concerns and comments.

Please note that 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, as section 4(b)(1)(A) of the Act directs that determinations as to whether any species is a threatened or endangered species must be made “solely on the basis of the best scientific and commercial data available.”

You may submit your comments and materials concerning this proposed rule by one of the methods listed in the
ADDRESSES
section. We request that you

send comments only by the methods described in the
ADDRESSES
section.

If you submit information via
http://www.regulations.gov,
your entire submission—including any personal identifying information—will be posted on the Web site. If your submission is made via a hardcopy that includes personal identifying information, you may request at the top of your document that we withhold this information from public review. However, we cannot guarantee that we will be able to do so. We will post all hardcopy submissions on
http://www.regulations.gov.
Please include sufficient information with your comments to allow us to verify any scientific or commercial information you include.

Comments and materials we receive, as well as supporting documentation we used in preparing this proposed rule, will be available for public inspection on
http://www.regulations.gov,
or by appointment, during normal business hours, at the U.S. Fish and Wildlife Service, Washington Fish and Wildlife Office (see
FOR FURTHER INFORMATION CONTACT
).

Previous Federal Actions

Candidate History

We first identified the Taylor's checkerspot butterfly and the streaked horned lark as candidates for listing in the 2001 Notice of Review of Native Species that are Candidates for Listing as Endangered or Threatened (CNOR) (USFWS 2001). All candidate species are assigned listing priority numbers (LPN) that are based on the immediacy and magnitude of threats and taxonomic status. In 2001, both of these species were assigned an LPN of 6, which reflects threats of a high magnitude that are not considered imminent.

In 2004, based on new information, we determined that the Taylor's checkerspot butterfly faced imminent threats of a high magnitude and reassigned it an LPN of 3 (69 FR 24876; May 4, 2004). In 2006, the streaked horned lark was also reassigned an LPN of 3. During our review we determined that the continued loss of suitable lark habitat, risks to the wintering populations; and plans for development, hazing, and military training activities (71 FR 53755; September 12, 2006) were imminent threats to the subspecies. The candidate status for Taylor's checkerspot butterfly and streaked horned lark was most recently reaffirmed in the October 26, 2011, CNOR (USFWS 2011). The U.S. Fish and Wildlife Service (Service) completed action plans for Taylor's checkerspot butterfly and streaked horned lark

and

set conservation targets and identified actions to achieve those targets over the next 5 years. These plans can be found on the Service's Web site at:
http://ecos.fws.gov/docs/action_plans/doc3089.pdf
(Taylor's checkerspot butterfly) and
http://www.fws.gov/wafwo/pdf/STHL_Action%20Plan_Sept2009.pdf
(streaked horned lark).

Petition History

In 2001, we developed internal, discretionary candidate assessment documents for the Taylor's checkerspot butterfly and streaked horned lark. These candidate assessments were published in the
Federal Register
on October 30, 2001 (USFWS 2001). On December 10, 2002, we received two separate petitions for these species. The first was from the Xerces Society, Center for Biological Diversity, Oregon Natural Resources Council, Friends of the San Juans, and Northwest Ecosystem Alliance to list the Taylor's checkerspot butterfly (also known as “whulge checkerspot”)
(Euphydryas editha taylori)
as endangered. The petitioners requested that critical habitat be designated. We also received a petition from the Center for Biological Diversity, Friends of the San Juans, Oregon Natural Resources Council, and Northwest Ecosystem Alliance requesting that we list the streaked horned lark (
Eremophila alpestris strigata
) as endangered and designate critical habitat concurrent with the listing. Because the Service had already determined that these species warranted listing and placed them on the candidate list in 2001, we have been evaluating these species as resubmitted petition findings on an annual basis. On July 12, 2011, the Service filed a multiyear work plan as part of a proposed settlement agreement with the Center for Biological Diversity and others, in a consolidated case in the U.S. District Court for the District of Columbia. The settlement agreement was approved by the court on September 9, 2011, and will enable the Service to systematically review and address the conservation needs of more than 250 candidate species, over a period of 6 years, including the Taylor's checkerspot butterfly and streaked horned lark. These proposed rules fulfill, in part, the terms of that settlement agreement.

Background

We discuss below only those topics directly relevant to the proposed listing of the Taylor's checkerspot butterfly and the streaked horned lark in this section of the proposed rule.

Species Information—Taylor's Checkerspot Butterfly

Taylor's checkerspot butterflies are medium-sized, colorfully marked butterflies with a checkerboard pattern on the upper (dorsal) side of the wings (Pyle 2002, p. 310). They are orange with black and yellowish (or white) spot bands, giving a checkered appearance (Pyle 1981, p. 607; Pyle 2002, p. 310). Taylor's checkerspot butterflies were historically known to occur in British Columbia, Washington, and Oregon, and current distribution has been reduced from over 80 locations rangewide to 14. Taylor's checkerspot butterflies produce one brood per year. They overwinter (diapause) in the fourth or fifth larval instar (developmental) phase and have a flight period as adults of 10 to 14 days, usually in May, although depending on local site and climatic conditions, the flight period begins in late April and extends into early July, as in Oregon, where the flight season may last for up to 45 days (Ross 2008, p. 2).

Taxonomy

Taylor's checkerspot butterfly is a subspecies of Edith's checkerspot butterfly (
Euphydryas editha
). The Taylor's checkerspot butterfly was originally described by W.H. Edwards (1888) from specimens collected from Beacon Hill Park in Victoria, British Columbia (BC).
Euphydryas editha taylori
is recognized as a valid subspecies by the Integrated Taxonomic Information System (ITIS 2012a). It is one of several rare and threatened subspecies, including the Bay checkerspot (
E. e. bayensis
) from the San Francisco Bay area and the Quino checkerspot (
E. e. quino
) from the San Diego, California, region; both are federally listed as endangered species. Several other subspecies of
Euphydryas editha
are known to occur in Washington and Oregon, including Bean's checkerspot (
E. e. beani
) known from the north Cascades of Washington; Strand's checkerspot (
E. e. edithana
) in the foothills of the Columbia Basin, including the low hills of the Blue Mountains in Washington and the Wallowa Mountains in Oregon, primarily east of where other subspecies are known; and Colonia checkerspot (
E. e. colonia
) known from high-elevation sites of the Olympic Peninsula and the Cascades of Washington and Oregon from the Wenatchee Mountains in Washington to the Siskiyou Mountains in Oregon.

Habitat and Life History

Taylor's checkerspot butterflies occupy open habitat dominated by

grassland vegetation throughout their range. In Washington, Taylor's checkerspot butterflies inhabit glacial outwash prairies in the south Puget Sound region; shallow-soil balds (a bald is a small opening on slopes in a treeless area, dominated by herbaceous vegetation) (Chappell 2006 p. 1) and grasses, within a forested landscape, roadsides, and former clear-cut areas within a forested matrix on the northeast Olympic Peninsula, and a coastal stabilized dune site near the Straits of Juan de Fuca (Stinson 2005, pp. 93-96). The two Oregon sites are found in the vicinity of Corvallis, Benton County, on grassland hills in the Willamette Valley (Vaughan and Black 2002, p. 7; Ross 2008, p. 1; Benton County 2010, Appendix N, p. 5). The recently discovered population on Denman Island in Canada (for details, see Current Range and Distribution, below), discovered in May 2005, occupies an area that had been clear-cut harvested, and is now dominated by, and maintained as, grass and forb vegetation. This is the first record for the species in British Columbia since 1998 (Heron 2008, pers. comm.; Page
et al.
2009, p. 1). In British Columbia, Canada, Taylor's checkerspot butterflies were historically known to occupy coastal grassland habitat, not forests that were converted to early successional conditions by clear-cutting, on Vancouver Island and nearby islands.

Female Taylor's checkerspot butterflies and their larvae utilize plants that contain defensive chemicals known as iridoid glycosides, which have been recognized to influence the selection of oviposition sites by adult nymphalid butterflies (butterflies in the family Nymphalidae) (Murphy
et al.
2004, p. 22; Page
et al.
2009, p. 2), and function as a feeding stimulant for some checkerspot larvae (Kuussaari
et al.
2004, p. 147). As maturing larvae feed, they accumulate these defensive chemical compounds from their larval host plants into their bodies. According to the work of Bowers (1981, pp. 373-374), this accumulation appears to deter predation. These larval host plants include members of the Broomrape family (Orobanchaceae), such as
Castilleja
(paintbrushes) and
Orthocarpus = Tryphysaria
(owl's clover), and native and nonnative
Plantago
species, which are members of the Plantain family (Plantaginaceae) (Pyle 2002, p. 311; Vaughan and Black 2002, p. 8). The recent rediscovery in 2005 of Taylor's checkerspot butterflies in Canada indicated that additional food plants (
Veronica serpyllifolia
(thymeleaf speedwell) and
V. beccabunga
ssp.
Americana
(American speedwell)) were being utilized by Taylor's checkerspot butterfly larvae (Heron 2008, pers. comm.; Page
et al.
2009, p. 2). Taylor's checkerspot butterfly larvae had previously been confirmed feeding on
Plantago lanceolata
(narrow-leaf plantain) and
P. maritime
(sea plantain) in British Columbia (Guppy and Shepard 2001, p. 311), narrow-leaf plantain and
Castilleja hispida
(harsh paintbrush) in Washington (Char and Boersma 1995, p. 29; Pyle 2002, p. 311; Severns and Grosboll 2011, p. 4), and feed exclusively on narrow-leaf plantain in Oregon (Dornfeld 1980, p. 73; Ross 2008, pers. comm.; Severns and Warren 2008, p. 476). Dr. Robert Michael Pyle has speculated that Taylor's checkerspot butterfly larvae likely fed upon the threatened
Castilleja levisecta
(golden paintbrush) in historical times when both species were more widespread and sympatric (overlapped) in their distribution (Pyle 2002, p. 311; Pyle 2007, pers. comm.).

Historical Range and Distribution

Historically, Taylor's checkerspot butterfly was likely distributed throughout grassland habitat found on prairies, shallow-soil balds, grassland bluffs, and grassland openings within a forested matrix in south Vancouver Island, northern Olympic Peninsula, the Puget Sound, and the Willamette Valley. The historical range and abundance of the species are not precisely known because extensive searches for Taylor's checkerspot butterfly did not occur until recently. Northwest prairies were formerly more common, larger, and interconnected, and would likely have supported a greater distribution and abundance of Taylor's checkerspot butterflies than prairie habitat does today. According to Pyle (2012,
in litt.
):

“
Euphydryas editha taylori
was previously more widely distributed and much denser in occurrence than is presently the case on the Puget Prairies. The checkerspot was abundant on the Mima Mounds National Area Preserve (NAP) and surrounding prairies in 1970. In the mid-eighties, the butterflies flew by the thousands on Rock Prairie, a private farm property west of Tenino. All of these sites have since been rendered unsuitable for
E. e. taylori
through management changes, and the butterfly has dropped out of them; meanwhile, many other colonies have disappeared in their vicinity through outright development or conversion of the habitat. The same is true for bluff-top colonies I knew in the early '70s at Dungeness. The ongoing loss and alteration of habitat in the western Washington grasslands has without question led to the shrinkage of Taylor's checkerspot occurrences from a regional constellation to a few small clusters.”

Before recent declines over roughly the last 10 or 15 years the Taylor's checkerspot butterfly was known from an estimated 80 locations: 24 in British Columbia, 43 in Washington, and 13 in Oregon (Hinchliff 1996, p. 115; Shepard 2000, pp. 25-26; Vaughan and Black 2002, p. 6; Stinson 2005, pp. 93-96, 123-124). These sites included coastal and inland prairies on southern Vancouver Island and surrounding islands in the Straits of Georgia, British Columbia and the San Juan Island archipelago (Hinchliff 1996, p. 115; Pyle 2002, p. 311), as well as open prairies on post-glacial gravelly outwash and shallow-soil balds in Washington's Puget Trough (Potter 2010, p. 1), the north Olympic Peninsula (Holtrop 2010, p. 1), and grassland habitat within a forested matrix in Oregon's Willamette Valley (Benton County 2010, Appendix N, p. 5).

The 1949 field season summary for North American lepidoptera (Hopfinger 1949, p. 89) states that an abundant distribution of Taylor's checkerspot butterfly was known from the south Puget Sound prairies: “
Euphydryas editha
(
taylori
), as usual, appeared by the thousands on Tenino Prairie.” By 1989, Pyle (p. 170) had reported that there were fewer than 15 populations remaining rangewide. Surveys in 2001 and 2002 of the three historical locations on Hornby Island, British Columbia, failed to detect any Taylor's checkerspot butterflies; the last observation of the Taylor's checkerspot butterfly from this location was 1995 (Committee on the Status of Endangered Wildlife in Canada (COSEWIC) 2011, p. 15). By fall 2002, only six populations were known to occur rangewide, four from the south Puget Sound region in Washington, one from San Juan County, Washington, and one from the Willamette Valley of Oregon (USFWS 2002a).

Current Range and Distribution

Based on historical and current data, the distribution and abundance of Taylor's checkerspot butterflies have declined significantly rangewide with the majority of local extirpations occurring from approximately the mid-1990s in Canada (COSEWIC 2011, p. 15), 1999-2004 in south Puget Sound, and around 2006 at the Bald Hills location. Several new locations harboring Taylor's checkerspot butterflies have been rediscovered on historical sites on Washington Department of Natural Resources (WDNR) lands (USFWS 2004, pp. 3-4; USFWS 2007, p. 5) and have also been found at new locations on natural and manipulated balds within the upper

Dungeness River watershed in Washington. Currently 13 individual populations of Taylor's checkerspot butterflies are known to occur; these populations are distributed in British Columbia, Canada (1), Washington (10), and Oregon (2).

Nearly all localities for Taylor's checkerspot butterflies in British Columbia have been lost; the only location currently known from British Columbia was discovered in 2005 (COSEWIC 2011, p. iv). In Oregon, although many surveys have been conducted at a variety of historical and potential locations within the Willamette Valley, many of those have failed to detect the species; the number of locations occupied by Taylor's checkerspot butterflies has declined from 13 to 2 (Ross 2011,
in litt.,
p. 1). In Washington State, more than 43 historical locales were documented for Taylor's. In 2012, we have 11 documented locations for Taylor's checkerspot butterflies with only 1 of the localities harboring more than 1,000 individuals, and the majority of known sites have daily counts of fewer than 100 individual butterflies.

Due to the limited distribution and few populations of Taylor's checkerspot butterfly, surveys for this species are quite thorough, generally consisting of a minimum of 3 days of visits during the flight period, and occasionally numbering up to 10 or 12 days of counts. Multiple days of counts during the annual flight period greatly increases the reliability of abundance data for butterflies, thus we believe the data on numbers of Taylor's checkerspot butterflies to be highly reliable.

Canada

After years of surveys (2001 through 2004) at historical population sites in British Columbia that failed to detect Taylor's checkerspot butterflies (COSEWIC 2011, pp. 15-16), a population was discovered on Denman Island in 2005. Denman Island is located approximately 106 miles (170 km) north of Victoria, British Columbia, along the eastern shores of Vancouver Island in the Straits of Georgia. Taylor's checkerspot butterfly records from British Columbia date from 1888 through 2011, when the last survey was conducted. Surveys are regularly conducted on Vancouver Island and other historical locations (Page
et al.
2009, p. iv). In 2008, a single Taylor's checkerspot butterfly was detected on Vancouver Island in the Courtney-Comox area, where they had not been observed since 1931 (COSEWIC 2011, pp. 15-16). Additional surveys were conducted at this location and only the single butterfly was observed. It is likely that this single adult had dispersed from the Denman Island population located approximately 0.3 mi (0.5 km) away. As of 2012, the only existing known population for Taylor's checkerspot butterflies in Canada is on Denman Island (Page
et al.
2009, p. 2; COSEWIC 2011, p. iv).

Washington

In Washington, surveys have been conducted annually for Taylor's checkerspot butterflies in currently and historically occupied sites. Surveys on south Puget Sound prairies have been conducted from 1997 through 2011 by the Washington Department of Fish and Wildlife (WDFW), WDNR, The Nature Conservancy of Washington (now the Center for Natural Lands Management), and personnel from the Wildlife Branch of Joint Base Lewis-McChord (JBLM; formerly known as Fort Lewis). In 1994, a report from Char and Boersma (1995) indicated the presence of Taylor's checkerspot butterflies on the 13th Division Prairie on JBLM; no additional locations have been reported since 1999, when a handful of Taylor's checkerspot butterflies were observed by WDFW (Hays
et al.
2000, p. 13). Surveys have been conducted annually in this area since 2000; however, no Taylor's checkerspot butterflies have been detected during the spring flight period (Ressa 2003, pp. 7, 14; Gilbert 2004, p. 5; Linders 2012c,
in litt.
). Taylor's checkerspot butterflies are believed to be extirpated from the 13th Division Prairie at JBLM (Linders 2012c,
in litt.
).

Four other populations in Thurston County (Glacial Heritage, Scatter Creek north and south units, and Rocky Prairie NAP) had Taylor's checkerspot butterflies present in 1997. No adult Taylor's checkerspot butterflies were observed during surveys conducted in 1998 and 1999 at these locations (Hays
et al.
2000, p. 13; Stinson 2005, p. 95). Subsequent annual surveys at these four sites have not detected Taylor's checkerspot butterflies (with the exception of two sites where the butterfly has recently been translocated (Linders and Olson 2011, p. 17; Bidwell 2012, pers. comm.)).

Four historical locales for Taylor's checkerspot butterflies were permanently lost in the south Puget Sound region to development (Dupont, JBLM Training Area 7S, Spanaway, and Lakewood in Pierce County) or conversion to agriculture (Rock Prairie in Thurston County) (Stinson 2005, pp. 93-96). In addition, several older Washington specimens are labeled with general or imprecise locality names on their collection labels (e.g., Olympia 1893; Tenino 1929; Shelton 1971, Dungeness 1999) (Stinson 2005, pp. 94-95). Some of these site names may refer to unknown or currently occupied locales but due to their imprecise nature, the true location of these potential populations has not been determined.

Surveys of 15 prairies within the south Puget Sound landscape in 2001 and 2002 located Taylor's checkerspot butterflies on only 4 sites in Thurston and Pierce Counties (Stinson 2005, pp. 93-96). Three of the four sites were found in the Bald Hill landscape in Southeast Thurston County. Taylor's checkerspot butterflies were documented at the Bald Hills through 2007, but there have been no detections since, despite regular and thorough surveying from 2001 through 2011 (Potter 2011, p. 3). This number has declined substantially in recent years as habitat has become increasingly shaded and modified by encroaching trees, nonnative grasses, and the invasive, nonnative shrub Scot's broom (
Cytisus scoparius
). Potter (2010, p. 1) reported multiple site visits to conduct redundant surveys in formerly occupied bald habitats during the 2008-2010 flight period with no Taylor's checkerspot butterflies observed. The species is presumed to be extirpated from this location.

The 91st Division Prairie is located on JBLM on the eastern edge of the approximately 6,000 acre (2,400 ha) prairie. The largest current populations of Taylor's checkerspot butterfly within the south Puget Sound have been observed here, and have served as the source populations for the collection of larvae for captive breeding to support translocation efforts. Several small, discrete patches of habitat are occupied by Taylor's checkerspot butterflies. The close proximity of these patches indicates that a relatively robust population (more than 1,000 butterflies surveyed in a single day in 2006) is likely present at JBLM.

In the course of conducting surveys for another rare grassland-associated butterfly found in Washington, the island marble (
Euchloe ausonides insulanus
), over 150 potential grassland locations were surveyed for Taylor's checkerspot butterfly in the north Puget Sound region during spring of 2005 through the spring of 2011 (Miskelly 2005; Potter
et al.
2011) where historical locales for Taylor's checkerspot butterflies exist (Pyle 1989, p. 170). Although the flight periods and habitat of both butterflies overlap, no Taylor's checkerspot butterflies were found during these surveys.

Several historical sites with potentially suitable habitat were surveyed on the north Olympic Peninsula (Clallam County) during spring 2003. Taylor's checkerspot butterfly was found to occupy five locations in this geographic area in 2003. At one historical site near the mouth of the Dungeness River, only a few individuals were detected. However, no Taylor's checkerspot butterflies were detected at this location during surveys from 2005 through 2009 (McMillan 2007, pers. comm.; Potter 2012, pers. comm.). The other four populations were found on grassy openings on shallow-soiled bald habitat west of the Elwha River. Two of these sites were estimated to support at least 50 to 100 adult Taylor's checkerspot butterflies (Dan Kelly Ridge and Eden Valley), and just a few individuals were found at the two other bald sites (Striped Peak and Highway 112) (Hays 2011, p. 1). Subsequent surveys at the latter two sites, Striped Peak and Highway 112, from 2004-2011, have failed to relocate or detect any Taylor's checkerspot butterflies.

In 2006 a population was discovered near the town of Sequim. Taylor's checkerspot butterflies have since been detected annually at this location from 2006-2011 (Hays 2009, pers. comm.; Hays 2011, p. 29). At this site, Taylor's checkerspot butterflies inhabit approximately 5 ac (2 ha) of estuarine, deflation plain (or back beach), a road with restricted use, and farm-edge habitat. In 2010, a maximum count of 568 Taylor's checkerspot butterflies was recorded on a single day (April 3, 2010); normally peak daily counts from this location range from 50 to 240 individuals (Hays 2011, p. 29).

Since 2007, three new Taylor's checkerspot butterfly populations have been found in Clallam County on Olympic National Forest lands. All three sites are located in the Dungeness River watershed: Bear Mountain, Three O'Clock Ridge, and Upper Dungeness (Holtrop 2009, p. 2). The Forest Service and WDFW are currently monitoring butterfly numbers at these sites annually. As of 2012, a total of six occupied sites are known from Clallam County: Sequim, Eden Valley, Bear Mountain, Three O'Clock Ridge, and Upper Dungeness.

Oregon

All of the 13 historical locales within the Willamette Valley of western Oregon have been surveyed regularly by local lepidopterists (McCorkle 2008, pers. comm.; Ross 2005: Stinson 2005, p. 124; Benton County 2010, p. 13; Potter 2012, pers. comm.). Taylor's checkerspot butterflies were formerly reported to exist in large numbers (“swarms on the meadows beside Oak Creek”) on the upland prairies of the Willamette Valley in Lane, Benton, and Polk Counties (Dornfeld 1980, p. 73). Now only remnant populations exist in Oregon. In 1999, Taylor's checkerspot butterflies were discovered along the Bonneville Power Administration (BPA) right-of-way corridor in an area known as Fitton Green in Benton County. In 2004 surveys for Taylor's checkerspot butterfly were expanded in the Willamette Valley where a second population was discovered on grassland openings within the Beazell Memorial Forest in Benton County. These two locations for Taylor's checkerspot butterfly are currently the only occupied patches known from Oregon.

Population Estimates/Status

There is little historical information on population estimates for Taylor's checkerspot butterflies and the survey techniques used for monitoring have differed over time. Early surveys at most locations were done using Pollard transect sampling methodology. Prior to implementing distance sampling as the accepted survey method for Taylor's checkerspot butterflies, population sizes were determined by tallying the number of all butterflies observed in a day and this was expressed as the maximum day count for a population at a specific site. During the survey season from 2007 through 2011, WDFW implemented distance sampling methods to estimate abundance at the site in Washington on JBLM. Distance sampling involves establishing permanent transects over a proportion of the survey area to determine the probability of detecting the butterfly. This number is used to calculate abundance (Marques 2009). Because Taylor's checkerspot butterfly population numbers change daily due to emergence and mortality of individuals, density estimates were computed by survey date (Linders and Olson 2011, p. 11). Although the sampling methods have changed over the years, we believe they are useful in providing a general estimate of population trend information. Additionally, since 2007, a consistent survey method for distance sampling has been implemented throughout most of the range, providing reliable annual information.

Canada

The recently discovered population in British Columbia (BC) was confirmed by the invertebrate specialist for the BC Ministry of the Environment (Heron 2008, pers. comm.). A total of 12 adults were observed on Denman Island during 2005 (Table 1) (Page
et. al.
2009, p. 1). We have no reports regarding counts for 2006 surveys. However, in 2007, more than 600 butterflies were detected and tallied from this location during the entire survey effort (Heron 2008, p. 5). Surveys at this location in 2008 detected 324 Taylor's checkerspot butterflies (Page
et al.
2009, p. 17). In 2009, a mark-recapture study of Taylor's was conducted on Denman Island. Over 1,200 butterflies were marked and 45 were recaptured. Based on this study the population was estimated at 13,000 individual butterflies; however, this estimate is likely exaggerated and inaccurate since the survey efforts were not consistent over the course of the study (COSEWIC 2011, p. 38). During the same flight period in 2009, an additional 950 individuals were observed on Denman Island (COSEWIC 2011, p. 38). Only 12 butterflies were observed in 2011 by the same surveyors using identical methods at the same location.

Washington

In Washington State, more than 43 historical locales were documented as having Taylor's checkerspot butterfly populations. In 2012, there are only 11 documented populations, with only 1 of the sites harboring more than 1,000 individuals at any time and the majority of known sites yielding daily counts of fewer than 100 individual butterflies. These locations are as follows: Striped Peak, Highway 112, Sequim, Eden Valley, Dan Kelly Ridge, Bear Mountain, Three O'Clock Ridge, Upper Dungeness, 91st Division Prairie on JBLM, Scatter Creek Wildlife Area, and the Bald Hills.

Taylor's checkerspot butterflies have been surveyed annually on the northeastern Olympic peninsula since 2003. Striped Peak, located on WNDR lands, supported Taylor's checkerspot butterflies as early as 1985. Between 2003 and 2005, only a few adult butterflies were observed by WDFW personnel at Striped Peak and a second site known as Highway 112. No butterflies have been observed at the Striped Peak or Highway 112 locations since that time (McMillan 2009, pers. comm.; Hays 2011, p. 1). Both sites are being encroached by
Pseudotsuga menziesii
(Douglas-fir) native shrubs, and the invasive shrub Scot's broom (Thomas 2011, pers. obs.).

In 2006, at the Sequim population, as many as 100 butterflies were detected on a single day; however, on many days fewer butterflies were observed (McMillan 2007, pers. comm.). In spring 2007, researchers detected 100 to 200 butterflies on peak days. Both larvae and adults were present at this site in

2007 and 2008 (Potter 2012b,
in litt.
). At Eden Valley, up to 60 butterflies had been detected on a single day survey prior to surveys in 2006, but fewer than 30 were detected during the 2006 surveys. During surveys conducted between 2007 and 2011, maximum daily counts ranged between 50 and 538 individuals (Potter 2012b,
in litt.
).

On Dan Kelly Ridge, as many as 50 butterflies were detected during surveys on a single day in 2006. This is a large, linear site with a ridgeline road greater than 2 miles (3.2 km) long; grassland habitat with larval food plants are found along the road margins and in forest openings on steep south facing slopes where shallow-soil balds support Taylor's checkerspot butterflies. Between 2007 and 2010, maximum daily counts ranged from 60 to 100 butterflies. Surveys were not conducted at this site in 2011.

In 2007, on Three O'Clock Ridge in the upper Dungeness watershed of Olympic National Forest, a small number (two) of Taylor's checkerspot butterflies were first detected (Holtrop 2010, p. 1). This site was surveyed in 2008 by Forest Service and WDFW personnel who detected 12 adult butterflies (Holtrop 2010, p. 1). In 2009, approximately 300 ac (121 ha) of suitable habitat were surveyed (Holtrop 2010, p. 5) and two new populations were discovered, at Upper Dungeness and Bear Mountain. Maximum single day counts ranged from 40 to 69 butterflies at the Three O'Clock Ridge, Upper Dungeness, and Bear Mountain. These sites have supported Taylor's checkerspot butterflies consistently since their discovery (Holtrop 2010, p. 13).

The largest known population of Taylor's checkerspot butterfly is located on the 91st Division Prairie at JBLM where a high complement of larval and nectar host plants exist. During the 2005 and 2006 flight seasons (Combs 2005, p. 8; Wolford 2006, pp. 18-20), more than 1,000 individuals were detected on maximum single day counts and hundreds of individuals were observed throughout the flight season (Combs 2005, p. 8; Wolford 2006, pp. 18 and 20). Surveys in spring 2007 detected slightly lower numbers despite the high survey effort. In 2007, the single-day maximum count for Taylor's checkerspot butterflies was 637 (Wolford
et al.
2007, p. 8). This decrease in butterfly numbers was observed elsewhere for Taylor's checkerspot butterfly in Thurston County during 2007, and is likely related to weather conditions that year. In 2008, detections at 91st Division Prairie indicated a further decline to 187 butterflies, a 37 percent decline from the 2007 surveys (Linders 2012,
in litt.
).

During 10 surveys conducted in the spring of 2009 at 91st Division Prairie, 77 individual butterflies were counted as a maximum daily count (Linders 2009a, entire; Thomas 2009b, pers. obs.). Spring counts in 2009, 2010, and in 2011 showed a general trend of increasing observations at this site, apparently because of a rebound in larval food plants along the roads margins used by military training vehicles, and from repeated and frequent fires caused by military training exercises. Oviposition on larval host plants (narrow-leaf plantain) near road margins was observed at all known Taylor's checkerspot butterfly locations in Washington State (Severns and Grosboll 2011, p. 66).

Experimental introductions of Taylor's checkerspot butterflies have been attempted in the south Puget Sound region. In 2006, Taylor's checkerspot butterfly larvae were placed out at four locations in Thurston and Pierce County: (1) In March 2006, larvae were released at Glacial Heritage Preserve, a Thurston County park; (2) in June 2006, larvae were placed at two locations on JBLM (Training Area 7 South (TA 7S) and 13th Division Prairie); and (3) at the Scatter Creek Wildlife area in Thurston County. None of these initial test releases resulted in observations of adult butterflies at these locations during the subsequent flight season (Linders 2007, p. vi). A subsequent release of 199 larvae in March 2007 at Scatter Creek Wildlife Area resulted in 11 Taylor's checkerspot butterfly observations there in May 2007 (Linders 2007, p. 18).

Based on this early success with captive rearing of larvae, an additional 340 larvae were placed at Scatter Creek Wildlife Area in March 2008. A peak daily count of 16 adult Taylor's checkerspot butterflies were documented at this location in 2008 (Linders 2011c). In 2009, Linders released approximately 2,250 post-diapause larvae onto suitable habitat at Scatter Creek Wildlife Areas and 13th Division Prairie on JBLM, which resulted in 48 observations of adult butterflies and a peak day count of 36 adults at Scatter Creek South, two adults at Scatter Creek North and 1 individual at 13th Division Prairie on JBLM (Linders 2010,
in litt.,
entire). In 2010, 155 adult butterflies were detected at Scatter Creek Wildlife Area, and 207 adults were detected (counted) at Range 50 on JBLM (Linders and Olson 2011, p. 23). During late winter of 2010, a total of 2,036 post-diapause larvae were released onto restored prairie habitat at Scatter Creek Wildlife Area and Range 50 on the 91st Division Prairie on JBLM in the south Puget Sound region (Linders and Olson 2011, p. 17. During distance survey counts in 2011, 84 adult butterflies were counted at Scatter Creek Wildlife Area, and 903 adults were counted at Range 50 on the 91st Division Prairie on JBLM (Linders and Olson 2011, p. 23).

Surveys of private property and WDNR-managed land in the Bald Hill area in 2006 detected only a few individual Taylor's checkerspot butterflies during any given survey day on each of the primary balds. Reports and personal observation indicate that the density and composition of larval host plants have declined at the Bald Hills area and portions of some of the balds have been invaded by Douglas-fir and other shrub species, including Scot's broom, thus reducing the area and suitability of habitat (Potter 2011, p. 1). Taylor's checkerspot butterflies have not been detected in the Bald Hills area since 2007, despite intensive survey efforts in 2008 and 2011 (Potter 2011, p. 1). This population of Taylor's checkerspot butterfly is presumed to be extirpated.

Oregon

In Oregon, Taylor's checkerspot butterflies are known from two locations in the Willamette Valley of Benton County, Beazell Memorial Park (BMP) and Fitton Green Natural Area. Annually, population estimates at these two sites have varied from greater than 1,200 butterflies at Fitton Green in 2005 to as few as 150 butterflies in 2006 at BMP (Ross, 2010, pp. 4, 6; Ross 2011,
in litt.
). During spring of 2010, the flight period began later than normally, due to cool, wet weather that persisted over much of the Pacific Northwest. In 2011, the flight season for Taylor's checkerspot butterfly in Oregon began later than any year since surveys commenced (Ross 2012, p. 3). In 2010 and 2011, total population counts were 991 and 516 for Fitton Green (Ross 2012, p. 4), and 849 and 223 for the BMP location (Ross 2012, p. 6), respectively.

Species Information—Streaked Horned Lark

The streaked horned lark is endemic to the Pacific Northwest (British Columbia, Washington, and Oregon; Altman 2011, p. 196) and is a subspecies of the wide-ranging horned lark (
Eremophila alpestris
). Horned larks are small, ground-dwelling birds, approximately 16-20 centimeters (6-8 inches) in length (Beason 1995, p. 2). Adults are pale brown, but shades of

brown vary geographically among the subspecies. The male's face has a yellow wash in most subspecies. Adults have a black bib, black whisker marks, black “horns” (feather tufts that can be raised or lowered), and black tail feathers with white margins (Beason 1995, p. 2). Juveniles lack the black face pattern and are varying shades of gray, from almost white to almost black with a silver-speckled back (Beason 1995, p. 2). The streaked horned lark has a dark brown back, yellowish underparts, a walnut brown nape and yellow eyebrow stripe and throat (Beason 1995, p. 4). This subspecies is conspicuously more yellow beneath and darker on the back than almost all other subspecies of horned lark. The combination of small size, dark brown back, and yellow underparts distinguishes this subspecies from all adjacent forms.

Taxonomy

The horned lark is found throughout the northern hemisphere (Beason 1995, p. 1); it is the only true lark (Family Alaudidae, Order Passeriformes) native to North America (Beason 1995, p. 1). There are 42 subspecies of horned lark worldwide (Clements
et al.
2011, entire). Twenty-one subspecies of horned larks are found in North America; 15 subspecies occur in western North America (Beason 1995, p. 4). Subspecies of horned larks are based primarily on differences in color, body size, and wing length. Molecular analysis has further borne out these morphological distinctions (Drovetski
et al.
2005, p. 875). Western populations of horned larks are generally paler and smaller than eastern and northern populations (Beason 1995, p. 3). The streaked horned lark was first described as
Otocorys alpestris strigata
by Henshaw (1884, pp. 261-264, 267-268); the type locality was Fort Steilacoom, Washington (Henshaw 1884, p. 267). There are four other breeding subspecies of horned larks in Washington and Oregon: Pallid horned lark (
E. a. alpina
), dusky horned lark (
E. a. merrilli
), Warner horned lark (
E. a. lamprochroma
), and arctic horned lark (
E. a. articola
) (Marshall
et al.
2003, p. 426; Wahl
et al.
2005, p. 268). None of these other subspecies breed within the range of the streaked horned lark, but all four subspecies frequently overwinter in mixed species flocks in the Willamette Valley (Marshall
et al.
2003, pp. 425-427).

Drovetski
et al.
(2005, p. 877) evaluated the genetic distinctiveness, conservation status, and level of genetic diversity of the streaked horned lark using the complete mitochondrial ND2 gene. Samples from 32 streaked horned larks in western Washington and 66 horned larks from Alaska, alpine Washington, eastern Washington, eastern Oregon, and California were analyzed. The 30 haplotypes identified from the 98 horned larks formed three clades: Pacific Northwest (alpine and eastern Washington, Alaska), Pacific Coast (Puget Sound and Washington coast) and coastal California), and Great Basin (Oregon) (Drovetski
et al.
2005, p. 880)).

Streaked horned larks were closely related to the California samples and only distantly related to the three closest localities (alpine Washington, eastern Washington, and Oregon); only one of the eastern Washington individuals shared the streaked horned lark haplotype, indicating a single example of gene flow from western Washington to eastern Washington (Drovetski
et al.
2005, p. 880). There was no evidence of immigration into the streaked horned lark range from any of the sampled localities. Analyses indicate that the streaked horned lark population is well-differentiated and isolated from all other sampled localities, including coastal California, and has “remarkably low genetic diversity” (Drovetski
et al.
2005, p. 875). All 32 streaked horned lark individuals shared the same haplotype with no variation between sequences compared. All other localities had multiple haplotypes despite smaller sample sizes (Drovetski
et al.
2005, pp. 879-880).

The lack of mitochondrial DNA (mtDNA) diversity exhibited by streaked horned larks is consistent with a population bottleneck (Drovetski
et al.
2005, p. 881). The streaked horned lark is differentiated and isolated from all other sampled localities, and although it was “* * * historically a part of a larger Pacific Coast lineage of horned larks, it has been evolving independently for some time and can be considered a distinct evolutionary unit” (Drovetski
et al.
2005, p. 880). Thus, genetic analyses support the subspecies designation for the streaked horned lark (Drovetski
et al.
2005, p. 880), which has been considered a relatively well-defined subspecies based on physical (phenotypic) characteristics (Beason 1995, p. 4). The streaked horned lark is recognized as a valid subspecies by the Integrated Taxonomic Information System (ITIS 2012c).

Life History and Habitat

Horned larks forage on the ground in low vegetation or on bare ground (Beason 1995, p. 6); adults feed mainly on grass and weed seeds, but feed insects to their young (Beason 1995, p. 6). A study of winter diet selection found that streaked horned larks in the Willamette Valley eat seeds of introduced weedy grasses and forbs, focusing on the seed source that is most abundant (Moore 2008b, p. 9). In this Willamette Valley study, a variety of grasses (
Digitaria sanguinalis
(large crabgrass),
Panicum capillare
(witchgrass),
Sporobulum
sp. (dropseed)), and unidentified grasses (Poaceae) and forbs (
Chenopodium album
(common lambsquarters),
Amaranthus retroflexus
(redroot pigweed),
Trifolium arvense
(rabbitfoot clover) and
Kickxia
sp. (cancerweed)) were common in the winter diet of the streaked horned lark (Moore 2008b, p. 16).

Horned larks form pairs in the spring (Beason 1995, p. 11). Altman (1999, p. 11) used a small sample (n=3) of streaked horned lark territories in the Willamette Valley to give a mean territory size of 1.9 acres (0.77 ha) with a range of 1.5 to 2.5 acres (0.61 to 1.0 ha). Horned larks create nests in shallow depressions in the ground and line them with soft vegetation (Beason 1995, p. 12). Female horned larks select the nest site and construct the nest without help from the male (Beason 1995, p. 12). Streaked horned larks establish their nests in areas of extensive bare ground, and nests are placed adjacent to clumps of bunchgrass (Pearson and Hopey 2004, pp. 1-2). In the Willamette Valley, nests are almost always placed on the north side of a clump of vegetation or another object such as root balls or soil clumps (Moore and Kotaich 2010, p. 18). Studies from Washington sites (the open coast, Puget lowlands and the Columbia River islands) have found strong natal fidelity to nesting sites—that is, streaked horned larks return each year to the place they were born (Pearson
et al.
2008, p. 11).

The nesting season for streaked horned larks begins in mid-April and ends in the early part of August (Pearson and Hopey 2004, p. 11; Moore 2011, p. 32). Clutches range from 1 to 5 eggs, with a mean of 3 eggs (Pearson and Hopey 2004, p. 12). After the first nesting attempt in April, streaked horned larks will often re-nest in late June or early July (Pearson and Hopey 2004, p. 11). Young streaked horned larks leave the nest by the end of the first week after hatching, and are cared for by the parents until they are about 4 weeks old when they become independent (Beason 1995, p. 15).

Nest success studies (i.e., the proportion of nests that result in at least one fledged chick) in streaked horned larks report highly variable results. Nest success on the Puget lowlands of Washington is low, with only 28 percent

of nests successfully fledging young (Pearson and Hopey 2004, p. 14, Pearson and Hopey 2005, p. 16). According to reports from sites in the Willamette Valley, Oregon, nest success has varied from 23 to 60 percent depending on the site (Altman 1999, p. 1; Moore and Kotaich 2010, p. 23). At one site in Portland, Oregon, Moore (2011, p. 11) found 100 percent nest success.

Historically, nesting habitat was found on grasslands, estuaries, and sandy beaches in British Columbia, in dune habitats along the coast of Washington, in western Washington and western Oregon prairies, and on the sandy beaches and spits along the Columbia and Willamette Rivers. Today, the streaked horned lark nests in a broad range of habitats, including native prairies, coastal dunes, fallow and active agricultural fields, wetland mudflats, sparsely-vegetated edges of grass fields, recently planted Christmas tree farms with extensive bare ground, moderately- to heavily-grazed pastures, gravel roads or gravel shoulders of lightly-traveled roads, airports, and dredge deposition sites in the lower Columbia River (Altman 1999, p. 18; Pearson and Altman 2005, p. 5; Pearson and Hopey 2005, p. 15; Moore 2008, pp. 9-10, 12-14, 16). Wintering streaked horned larks use habitats that are very similar to breeding habitats (Pearson
et al.
2005b, p. 8).

Habitat used by larks is generally flat with substantial areas of bare ground and sparse low-stature vegetation primarily comprised of grasses and forbs (Pearson and Hopey 2005, p. 27). Suitable habitat is generally 16-17 percent bare ground, and may be even more open at sites selected for nesting (Altman 1999, p.18; Pearson and Hopey 2005, p. 27). Vegetation height is generally less than 13 in (33 cm) (Altman 1999, p.18; Pearson and Hopey 2005, p. 27). Larks eat a wide variety of seeds and insects (Beason 1995, p. 6), and appear to select habitats based on the structure of the vegetation rather than the presence of any specific food plants (Moore 2008, p. 19). A key attribute of habitat used by larks is open landscape context. Our data indicate that sites used by larks are generally found in open (i.e., flat, treeless) landscapes of 300 acres (120 ha) or more (Converse
et al.
2010, p. 21). Some patches with the appropriate characteristics (i.e., bare ground, low stature vegetation) may be smaller in size if the adjacent areas provide the required open landscape context; this situation is common in agricultural habitats and on sites next to water. For example, many of the sites used by larks on the islands in the Columbia River are small (less than 100 ac (40 ha)), but are adjacent to open water, which provides the open landscape context needed. Streaked horned lark populations are found at nearly every airport within the range of the subspecies, because airport maintenance requirements provide the desired open landscape context and short vegetation structure.

Although streaked horned larks use a wide variety of habitats, populations are vulnerable because the habitats used are often ephemeral or subject to frequent human disturbance. Ephemeral habitats include bare ground in agricultural fields and wetland mudflats; habitats subject to frequent human disturbance include mowed fields at airports, managed road margins, agricultural crop fields, and disposal sites for dredge material (Altman 1999, p. 19).

Historical Range and Distribution

The streaked horned lark's breeding range historically extended from southern British Columbia, Canada, south through the Puget lowlands and outer coast of Washington, along the lower Columbia River, through the Willamette Valley, the Oregon coast and into the Umpqua and Rogue River Valleys of southwestern Oregon.

British Columbia.
The streaked horned lark was never considered common in British Columbia, but local breeding populations were known on Vancouver Island, in the Fraser River Valley, and near Vancouver International Airport (Campbell
et al.
1997, p. 120; COSEWIC 2003, p. 5). The population declined throughout the 20th century (COSEWIC 2003, pp. 13-14); breeding has not been confirmed since 1978, and the subspecies is considered to be extirpated in British Columbia (COSEWIC 2003, p. 15). A single streaked horned lark was sighted on Vancouver Island in 2002 (COSEWIC 2003, p. 16).

Washington.
The first report of streaked horned lark in the San Juan Islands, Washington, was in 1948 from Cattle Point (Goodge 1950, p. 28). There are breeding season records of streaked horned larks from San Juan and Lopez Islands in the 1950s and early 1960s (Retfalvi 1963, p. 13; Lewis and Sharpe 1987, p. 148, 204), but the last record dates from 1962, when seven individuals were seen in July on San Juan Island at Cattle Point (Retfalvi 1963, p. 13). The WDFW conducted surveys in 1999 in the San Juan Islands (Rogers 1999, pp. 3-4). Suitable nesting habitat was visually searched and a tape recording of streaked horned lark calls was used to elicit responses and increase the chance of detections (Rogers 1999, p. 4). In 2000, MacLaren and Cummins (in Stinson 2005, p.63) surveyed several sites recommended by Rogers (1999) including Cattle Point and Lime Kiln Point on San Juan Island. No larks were detected in the San Juan Islands during either survey effort (Rogers 1999, p. 4; Stinson 2005, p. 63).

There are a few historical records of streaked horned larks on the outer coast of Washington near Lake Quinault, the Quinault River and the Humptulips River in the 1890s (Jewett
et al.
1953, p. 438; Rogers 2000, p. 26). More recent records reported larks at Leadbetter Point and Graveyard Spit in Pacific County in the 1960s and 1970s (Rogers 2000, p. 26). But no larks were detected on the Outer Coast during surveys conducted there in 1999 and 2000 (Stinson 2005, p. 63).

There are scattered records of streaked horned larks in the northern Puget Trough, including sightings in Skagit and Whatcom Counties in the mid-20th century (Altman 2011, p. 201). The last recorded sighting of a streaked horned lark in the northern Puget Trough was at the Bellingham Airport in 1962 (Stinson 2005, p. 52).

Over a century ago, the streaked horned lark was described as a common summer resident in the prairies of the Puget Sound region in Washington (Bowles 1898, p. 53; Altman 2011, p. 201). Larks were considered common in the early 1950s “in the prairie country south of Tacoma” and had been observed on the tide flats south of Seattle (Jewett
et al.
1953, p. 438). By the mid-1990s, only a few scattered breeding populations existed on the south Puget Sound on remnant prairies and near airports (Altman 2011, p. 201).

There are sporadic records of streaked horned larks along the Columbia River. Sightings on islands near Portland, Oregon, date back to the early 1900s (Rogers 2000, p. 27). A number of old reports of streaked horned larks from the Columbia River east of the Cascade Mountains have been re-examined, and have been recognized as the subspecies
Eremophila alpestris merrilli
(Rogers 2000, p. 27; Stinson 2005, p. 51). On the lower Columbia River, it is probable that streaked horned larks breed only as far east as Clark County, Washington, and Multnomah County, Oregon (Roger 2000, p. 27; Stinson 2005, p. 51).

Oregon.
The streaked horned lark's range extends south through the Willamette Valley of Oregon where it was considered abundant and a common summer resident over a hundred years ago (Johnson 1880, p. 636; Anthony 1886, p. 166). In the 1940s, the subspecies was described as a common permanent resident in the

southern Willamette Valley (Gullion 1951, p. 141). By the 1990s, the streaked horned lark was called uncommon in the Willamette Valley, nesting locally in small numbers in large open fields (Gilligan
et al.
1994, p. 205; Altman 1999, p. 18). In the early 2000s, a population of more than 75 breeding pairs was found at the Corvallis Municipal Airport, making this the largest population of streaked horned larks known (Moore 2008, p. 15).

The streaked horned lark, while occasionally present, was never reported to be more than uncommon on the Oregon coast. The subspecies was described as an uncommon and local summer resident all along the coast on sand spits (Gilligan
et al.
1994, p. 205); a few nonbreeding season records exist for the coastal counties of Clatsop, Tillamook, Coos, and Curry (Gabrielson and Jewett 1940, p. 403). Small numbers of larks were known to breed at the South Jetty of the Columbia River in Clatsop County, but the site was abandoned in the 1980s (Gilligan
et al.
1994, p. 205). There are no recent occurrence records from the Oregon coast.

In the early 1900s, the streaked horned lark was considered a common permanent resident of the Umpqua and Rogue River Valleys (Gabrielson and Jewett 1940, p. 402). The last confirmed breeding record in the Rogue Valley was in 1976 (Marshall
et al.
2003, p. 425). There are no recent reports of streaked horned larks in the Umpqua Valley (Gilligan
et al.
1994, p. 205; Marshall
et al.
2003, p. 425).

Current Range and Distribution

Breeding Range.
The streaked horned lark has been extirpated as a breeding species throughout much of its range, including all of its former range in British Columbia, the San Juan Islands, the northern Puget Trough, the Washington coast north of Grays Harbor, the Oregon coast, and the Rogue and Umpqua Valleys in southwestern Oregon (Pearson & Altman 2005, pp. 4-5).

The current range of the streaked horned lark can be divided into three regions: (1) The south Puget Sound in Washington; (2) the Washington coast and lower Columbia River islands (including dredge spoil deposition sites near the Columbia River in Portland, Oregon); and (3) the Willamette Valley in Oregon.

In the south Puget Sound, the streaked horned lark is found in Mason, Pierce, and Thurston Counties, Washington (Rogers 2000, p. 37; Pearson and Altman 2005, p. 23; Pearson
et al.
2005a, p. 2; Anderson 2009, p. 4). Recent studies have found that streaked horned larks currently breed on six sites in the south Puget Sound. Four of these sites (13th Division Prairie, Gray Army Airfield, McChord Field, and 91st Division Prairie) are on JBLM. Small populations of larks also breed at the Olympia Regional Airport and the Port of Shelton's Sanderson Field (airport) (Pearson and Altman 2005, p. 23; Pearson
et al.
2008, p. 3).

On the Washington coast, there are four known breeding sites: (1) Damon Point; (2) Midway Beach; (3) Graveyard Spit; and (4) Leadbetter Point in Grays Harbor and Pacific Counties. On the lower Columbia River, streaked horned larks breed on several of the sandy islands downstream of Portland, Oregon. Recent surveys have documented breeding streaked horned larks on Rice, Miller Sands Spit, Pillar Rock, Welch, Tenasillahe, Coffeepot, Whites/Browns, Wallace, Crims, and Sandy Islands in Wahkiakum and Cowlitz Counties in Washington, and Columbia and Clatsop Counties in Oregon (Pearson and Altman 2005, p. 23; Anderson 2009, p. 4; Lassen 2011,
in litt.
). The Columbia River forms the border between Washington and Oregon; some of the islands occur wholly in Oregon or Washington, and some are bisected by the State line. Larks also breed in Portland (Multnomah County, Oregon) at suitable sites near the Columbia River. These include an open field at the Rivergate Industrial Complex and the Southwest Quad at Portland International Airport; both sites are owned by the Port of Portland, and are former dredge spoil deposition fields (Moore 2011, pp. 9-12).

In the Willamette Valley, streaked horned larks breed in Benton, Clackamas, Lane, Linn, Marion, Polk, Washington, and Yamhill Counties. Larks are most abundant in the southern part of the Willamette Valley. The largest known population of larks is resident at Corvallis Municipal Airport in Benton County (Moore 2008. p. 15); other resident populations occur at the Baskett Slough, William L. Finley, and Ankeny units of the Service's Willamette Valley National Wildlife Refuge Complex (Moore 2008, pp. 8-9). Breeding populations also occur at municipal airports in the valley (including McMinnville, Salem, and Eugene) (Moore 2008, pp. 14-17). In 2008, a large population of streaked horned larks colonized a wetland and prairie restoration site on M-DAC Farms, a privately-owned parcel in Linn County; as the vegetation at the site matured in the following 2 years, the site became less suitable for larks, and the population declined (Moore and Kotaich 2010, pp. 11-13). This is likely a common pattern, as breeding streaked horned larks shift sites as habitat becomes available among private agricultural lands in the Willamette Valley (Moore 2008, pp. 9-11).

Wintering Range.
Pearson
et al.
(2005b, p. 2) found that the majority of streaked horned larks winter in the Willamette Valley (72 percent) and on the islands in the lower Columbia River (20 percent); the rest winter on the Washington coast (8 percent) or in the south Puget Sound (1 percent). In the winter, most of the streaked horned larks that breed in the south Puget Sound migrate south to the Willamette Valley or west to the Washington coast; streaked horned larks that breed on the Washington coast either remain on the coast or migrate south to the Willamette Valley; birds that breed on the lower Columbia River islands remain on the islands or migrate to the Washington coast; and birds that breed in the Willamette Valley remain there over the winter (Pearson
et al.
2005b, pp. 5-6). Streaked horned larks spend the winter in large groups of mixed subspecies of horned larks in the Willamette Valley, and in smaller flocks along the lower Columbia River and Washington Coast (Pearson
et al.
2005b, p. 7; Pearson and Altman 2005, p. 7). During the winter of 2008, a mixed flock of over 300 horned larks was detected at the Corvallis Municipal Airport (Moore 2011a, pers. comm.).

Population Estimates and Current Status

Data from the North American Breeding Bird Survey (BBS) indicate that most grassland-associated birds, including the horned lark, have declined across their ranges in the past three decades (Sauer
et al.
2011, pp. 3-5). The BBS can provide population trend data only for those species with sufficient sample sizes for analyses; there is insufficient data in the BBS for a rangewide analysis of the streaked horned lark's population trend (Altman 2011, p. 214). An analysis of recent data from a variety of sources concludes that the streaked horned lark has been extirpated from the Georgia Depression (British Columbia, Canada), the Oregon coast, and the Rogue and Umpqua Valleys (Altman 2011, p. 213); this analysis estimates the current rangewide population of streaked horned larks to be about 1,170-1,610 individuals (Altman 2011, p. 213).

In the south Puget Sound, approximately 150-170 streaked horned larks breed at six sites (Altman 2011, p. 213). Recent studies have found that larks have very low nest success in

Washington (Pearson
et al.
2008, p. 8); comparisons with other ground-nesting birds in the same prairie habitats in the south Puget Sound showed that streaked horned larks had significantly lower values in all measures of reproductive success (Anderson 2010, p. 16). Estimates of population growth rate (λ, lambda) that include vital rates from nesting areas in the south Puget Sound, Washington coast, and Whites Island in the lower Columbia River indicate that the Washington population is declining precipitously; one study estimated that the population of streaked horned larks was declining by 40 percent per year (λ = 0.61 ± 0.10 SD), apparently due to a combination of low survival and fecundity rates (Pearson
et al.,
2008, p. 12). More recent analyses of territory mapping at 4 sites in the south Puget Sound found that the total number of breeding streaked horned lark territories decreased from 77 territories in 2004 to 42 territories in 2007—a decline of over 45 percent in 3 years (Camfield
et al.
2011, p. 8). Pearson
et al.
(2008, p. 14) concluded that there is a high probability of south Puget Sound population loss in the future given the low estimates of fecundity and adult survival along with high emigration out of the Puget Sound.

On the Washington coast and Columbia River islands, there are about 120-140 breeding larks (Altman 2011, p. 213). Data from the Washington coast and Whites Islands were included in the population growth rate study discussed above; populations at these sites appear to be declining by 40 percent per year (Pearson
et al.
2008, p. 12). Conversely, nest success is very high at the Portland industrial sites (Rivergate and the Southwest Quad). In 2010, nearly all nests successfully fledged young (Moore 2011, p. 13); only 1 of 10 monitored nests lost young to predation (Moore 2011, pp. 11-12).

There are about 900-1,300 breeding streaked horned larks in the Willamette Valley (Altman 2011, p. 213). The largest known population of streaked horned larks breeds at the Corvallis Municipal Airport; depending on the management conducted at the airport and the surrounding grass fields each year, the population has been as high as 100 breeding pairs (Moore and Kotaich 2010, pp. 13-15). In 2007, a large (580-acre (235-ha)) wetland and native prairie restoration project was initiated at M-DAC Farms on a former rye grass field in Linn County (Cascade Pacific RC&D 2012, p. 1). Large semipermanent wetlands were created at the site, and the prairie portions were burned and treated with herbicides (Moore and Kotaich 2010, pp. 11-13). These conditions created excellent quality ephemeral habitat for streaked horned larks and the site was used by about 75 breeding pairs in 2008 (Moore and Kotaich 2010, p. 12), making M-DAC the second-largest known breeding population of streaked horned larks that year. M-DAC had high use again in 2009, but as vegetation at the site matured, the number of breeding larks has declined, likely shifting to other agricultural habitats (Moore and Kotaich 2010, p. 13).

We do not have population trend data in Oregon that is comparable to the study in Washington by Pearson
et al.
(2008, entire); however, research on breeding streaked horned larks indicates that nest success in the southern Willamette Valley is higher than in Washington (Moore 2011b, pers. comm.). The best information on trends in the Willamette Valley comes from surveys by the Oregon Department of Fish and Wildlife (ODFW); the agency conducted surveys for grassland-associated birds, including the streaked horned lark, in 1996 and again in 2008 (Altman 1999, p. 2; Myers and Kreager 2010, p. 2). Point count surveys were conducted at 544 stations in the Willamette Valley (Myers and Kreager 2010, p. 2); over the 12-year period between the surveys, measures of relative abundance of streaked horned larks increased slightly from 1996 to 2008 (Myers and Kreager 2010, p. 11). Population numbers decreased slightly in the northern Willamette Valley and increased slightly in the middle and southern portions of the valley (Myers and Kreager 2010, p. 11).

We do not have conclusive data on population trends throughout the lark's range, but the rapidly declining population on the south Puget Sound suggests that the range of the streaked horned lark may still be contracting.

Range Contraction

The streaked horned lark has experienced a substantial contraction of its range; it has been extirpated from all formerly documented locations at the northern end of its range (British Columbia, and the San Juan Islands and northern Puget Trough of Washington), the Oregon coast, and the southern edge of its range (Rogue and Umpqua Valleys of Oregon). The lark's current range appears to have been reduced to less than half the size of its historical range in the last 100 years. The pattern of range contractions for other Pacific Northwest species (e.g., western meadowlark (
Sturnella neglecta)
) shows a loss of populations in the northern part of the range, with healthier populations persisting in the southern part of the range (Altman 2011, p. 214). The streaked horned lark is an exception to this pattern—its range has contracted from both the north and the south simultaneously (Altman 2011, p. 215).

Summary of Factors Affecting the Species

Section 4 of the Act (16 U.S.C. 1533), and its implementing regulations at 50 CFR part 424, set forth the procedures for adding species to the Federal Lists of Endangered and Threatened Wildlife and Plants. Under section 4(a)(1) of the Act, we may list a species based on any of the following five factors: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; and (E) other natural or manmade factors affecting its continued existence. Listing actions may be warranted based on any of the above threat factors, singly or in combination. Each of these factors is discussed below.

In making this finding, information pertaining to each of the species in question in relation to the five factors provided in section 4(a)(1) of the Act is discussed below. In considering what factors might constitute threats, we must look beyond the mere exposure of the species to the factor to determine whether the species responds to the factor in a way that causes actual impacts to the species. If there is exposure to a factor, but no response, or only a positive response, that factor is not a threat. If there is exposure and the species responds negatively, the factor may be a threat and we then attempt to determine how significant a threat it is. If the threat is significant, it may drive or contribute to the risk of extinction of the species such that the species warrants listing as an endangered or threatened species as those terms are defined by the Act. This does not necessarily require empirical proof of a threat. The combination of exposure and some corroborating evidence of how the species is likely impacted could suffice. The mere identification of factors that could impact a species negatively is not sufficient to compel a finding that listing is appropriate; we require evidence that these factors are operative threats that act on the species to the point that the species meets the definition of an endangered or threatened species under the Act.

We considered and evaluated the best available scientific and commercial information in evaluating the factors

affecting each of the species under consideration in this proposed rule.

Factor A. The Present or Threatened Destruction, Modification, or Curtailment of Its Habitat or Range

Under this factor, the primary long term threats to Taylor's checkerspot butterfly and streaked horned lark are the loss, conversion, and degradation of habitat particularly to agricultural and urban development, successional changes to grassland habitat, and the spread of invasive plants.

The prairies of south Puget Sound and western Oregon are part of one of the rarest ecosystems in the United States (Noss
et al.
1995, p. I-2; Dunn and Ewing 1997, p. v). Dramatic changes have occurred on the landscape over the last 150 years, including a 90 to 95 percent reduction in the prairie ecosystem. In the south Puget Sound region, where most of western Washington's prairies historically occurred, less than 10 percent of the original prairie persists, and only 3 percent remains dominated by native vegetation (Crawford and Hall 1997, pp. 13-14). In the remaining prairies, many of the native bunchgrass communities have been replaced by nonnative pasture grasses (Rogers 2000, p. 41), which larks avoid using for territories and nest sites (Pearson and Hopey 2005, p. 27). In the Willamette Valley, Oregon, native grassland has been reduced from the most common vegetation type to scattered parcels intermingled with rural residential development and farmland; it is estimated that less than one percent of the native grassland and savanna remains in Oregon (Altman
et al.
2001, p. 261).

Development

Native prairies and grasslands have been severely reduced throughout the range of the Taylor's checkerspot butterfly and the streaked horned lark as a result of human activity due to conversion of habitat to residential and commercial development and agriculture. Prairie habitat continues to be lost, particularly to residential development (Stinson 2005, p. 70) by removal of native vegetation and the excavation and grading of surfaces and conversion to non-habitat (buildings, pavement, other infrastructure). Residential development is associated with increased infrastructure such as new road construction, which is one of the primary causes of landscape fragmentation (Watts
et al.
2007, p. 736). Activities that accompany low-density development are correlated with decreased levels of biodiversity, mortality to wildlife, and facilitated introduction of nonnative invasive species (Trombulak and Frissell 2000, entire; Watts
et al.
2007, p. 736). In the south Puget Sound lowlands, the glacial outwash soils and gravels underlying the prairies are deep and valuable for use in construction and road building, which leads to their degradation and destruction.

Since the 1850s, much of the Willamette Valley of Oregon has been altered by development (agricultural and urban). About 96 percent of the Willamette Valley is privately owned, and it is both the fastest growing area in Oregon and the most densely populated. The Willamette Valley provides about half of the state's agricultural sales, and 16 of top 17 private sector employers (manufacturing, high technology, forest products, agriculture, and services) are located there. The population projected for 2050 is approximately four million, or nearly double the current population (Oregon Department of Fish and Wildlife 2006, p. 237). The increase in population will result in increased building construction and road development, further impacting the remaining prairies and oak woodlands.

Taylor's Checkerspot Butterfly.
The habitat of Taylor's checkerspot butterfly is highly fragmented across the region due to agricultural and low-density residential development. Fragmentation due to residential and associated road development has led to a reduction of native larval host plants and adult nectar plants as introduced invasive plant species, primarily Mediterranean grasses and shrubs such as Scot's broom, increasingly dominate the landscape and outcompete native plant species (see discussion below, under Invasives). Construction directly destroys habitat, as does conversion, and may kill any sessile or slow-moving organism in the construction footprint (Trombulak and Frissell 2000, p. 19). Unlike many other species of butterflies, Taylor's checkerspot butterflies spend approximately 50 weeks of their life cycle as eggs, larvae, or pupae with only a brief window of time (approximately 1-2 weeks) as winged adults (Stinson 2005, p. 78). Commercial and residential development, construction of related infrastructure including roads, and conversion of habitat to incompatible uses such as gravel mining directly affects Taylor's checkerspot butterfly larvae by killing individuals and destroying habitat.

When in flight, butterflies become subject to mortality from collision with vehicles on roads associated with residential development, which is commonly known to affect animals of all sizes, but especially insects (Trombulak and Frissell 2000, p. 20). Since the short flight season of Taylor's checkerspot butterflies directly corresponds with their reproductive period, death of gravid females could lead to population level consequences such as failure of entire populations. These sorts of traffic-collision related deaths may disproportionately affect Taylor's checkerspot butterflies in comparison with other butterflies, as many other kinds of butterflies are in flight for periods much longer than just their reproductive window.

Four historical locales for Taylor's checkerspot butterflies in the south Puget Sound region were lost to development or conversion. Dupont, Spanaway, and Lakewood were all converted to urban areas, and JBLM Training Area 7S became a gravel pit (Stinson 2005, pp. 93-96).

Streaked Horned Lark.
Horned larks need expansive areas of flat, open ground to establish breeding territories. The large, flat, treeless areas that airports necessarily require have become attractive breeding sites for streaked horned larks as native prairies and scoured river banks in the Pacific Northwest have declined. Five of the six streaked horned lark nesting sites remaining in the Puget lowlands are located on or adjacent to airports and military airfields (Rogers 2000, p. 37; Pearson and Hopey 2005, p. 15). At least four breeding sites are found at airports in the Willamette Valley, including the largest known population at Corvallis Municipal Airport (Moore 2008, pp. 14-17). Stinson (2005, p. 70) concluded that if large areas of grass had not been maintained at airports, the streaked horned lark might have been extirpated from the south Puget Sound area. Although routine mowing to meet flight path regulations helps to maintain grassland habitat in suitable condition for nesting larks, the timing of mowing is critical.

Mowing during the active breeding season (mid-April to late July) can destroy nests or flush adults, which may result in nest failure (Pearson and Hopey 2005, p. 17; Stinson 2005, p. 72). Some of the airports in the range of the streaked horned lark have adjusted the frequency and timing of mowing in recent years to minimize impacts to larks (Pearson and Altman 2005, p. 10). In 2011, McChord Air Field at JBLM agreed to a mowing regime which would provide protections to the lark during their nesting period. Unfortunately, recent unseasonably wet weather hasn't allowed this strategy to be implemented. WDFW coordinates mowing schedules at the Olympia Airport to reduce impacts to larks.

In 2008, the Port of Olympia prepared an Interlocal Agreement with the WDFW that outlines management recommendations and mitigation for impacts to state-listed species from development at the airport. In December, 2010, a white paper and supplemental planning memorandum was developed as part of the Airport Master Plan Update (Port of Olympia 2010, entire). This document, which is outlined in Appendix 2 of the Master Plan Update, outlines management recommendations for the protection of critical areas and priority species, including the streaked horned lark. The recommendations include minimizing development, retaining open or bare ground, and avoiding mowing during the nesting season (March 15 through August 15) in known or potential lark nesting areas. Although the Port does not anticipate any development to occur in the streaked horned lark nesting areas within the next 20 years, the agreement is not a regulatory document that would preclude future development, which is a primary source of revenue for the Port.

Airport expansions could result in further losses of some populations. At the Olympia Airport, hangars were built in 2005 on habitat used by streaked horned larks for foraging, resulting in a loss of grass and forb-dominated habitat, which could result in a smaller local population due to reduced habitat availability for breeding and wintering larks (Pearson and Altman 2005, p. 12). Based on discussions with staff at Sanderson Field in Shelton, future development plans do not include impacts to streaked horned lark habitat at this time. The majority of the proposed development at Sanderson Field will occur in areas already impacted (between existing buildings). The West Ramp at Gray Army Air Field on JBLM was expanded in 2005 into areas previously used by breeding larks, resulting in a loss of available breeding habitat (Stinson 2005, p. 72).

At Portland International Airport, streaked horned larks nest in an area called the Southwest Quad; this is an old dredge material deposition site in a currently unused part of the airport. The Port of Portland, which owns the airport, may propose to develop the Southwest Quad to accommodate future expansion, though there is no current plan in place (Green 2012,
in litt.
). The future development of the Southwest Quad would result in the loss of at least 33 ac (13 ha) of habitat and three breeding territories (Moore 2011, p. 12).

The 13th Division Prairie at JBLM is used for helicopter operations (paratrooper practices, touch-and-go landings, and load drop and retrievals) and troop training activities. Foot traffic and training maneuvers that are conducted during the streaked horned lark breeding season likely are a contributing factor to nest failure and low nest success at 13th Division Prairie. Recently, a lark nest was destroyed at 13th Division Prairie by a porta-potty service vehicle (Linders 2012b,
in litt.
). Artillery training, off-road use of vehicles and troop maneuvers at the 91st Division Prairie are also conducted in areas used by larks during the nesting season. Because access into this training area is limited and streaked horned lark surveys are only conducted opportunistically, we do not know if or how many lark nests are lost due to military activities at 91st Division Prairie.

Industrial development has also reduced habitat available to breeding and wintering larks. The Rivergate Industrial Park, owned by the Port of Portland, is a large industrial site in north Portland near the Columbia River; the site is developed on a dredge spoil field, and still has some large areas of open space between the industrial buildings. Rivergate has been an important breeding site for streaked horned larks, and a wintering site for mixed flocks of up to five horned lark subspecies (including the streaked horned lark). In 1990, the field used by larks at Rivergate measured more than 260 ha (650 acres) of open sandy habitat (Dillon 2012, pers. comm.). In the years since, new industrial buildings have been constructed on the site; now only one patch of 32 ha (79 acres) of open dredge spoil field remains (Moore 2011, p. 9) and the breeding population has dropped from 20 pairs to 5 pairs in this time (Moore 2011, p. 10).

Loss of Ecological Disturbance Processes, Invasive Species, and Succession

The suppression and loss of ecological disturbance regimes, such as fire and flooding, across vast portions of the landscape has resulted in altered vegetation structure in the prairies and meadows and has facilitated invasion by nonnative grasses and woody vegetation, rendering habitat unusable for Taylor's checkerspot butterflies and streaked horned larks. The basic ecological processes that maintain prairies, meadows, and scoured river banks have disappeared from, or have been altered on, all but a few protected and managed sites.

Historically, the prairies and meadows of the south Puget Sound region of Washington and western Oregon are thought to have been actively maintained by the native peoples of the region, who lived here for at least 10,000 years before the arrival of Euro-American settlers (Boyd 1986, entire; Christy and Alverson 2011, p. 93). Frequent burning reduced the encroachment and spread of shrubs and trees (Boyd 1986, entire; Chappell and Kagan 2001, p. 42), favoring open grasslands with a rich variety of native plants and animals. Following Euro-American settlement of the region in the mid-19th century, fire was actively suppressed on grasslands, allowing encroachment by woody vegetation into the remaining prairie habitat and oak woodlands (Franklin and Dyrness 1973 p. 122; Boyd 1986, entire; Kruckeberg 1991, p. 287; Agee 1993, p. 360; Altman
et al.
2001, p. 262).

Fires on the prairie create a mosaic of vegetation conditions, which serve to maintain native prairie forbs like
Camassia quamash
(common camas)
Achillea millefolium
(yarrow) and
Lomatium
spp. (desert parsley or biscuit root), which are adult nectar foods for Taylor's checkerspot butterfly. Stands of native perennial grasses (
Festuca idahoensis
ssp.
roemeri
(Roemer's fescue)) are also well adapted to regular fires and produce habitat favorable to the Taylor's checkerspot butterfly. In some prairie patches fires will reset succession back to bare ground, creating early successional vegetation conditions suitable for both Taylor's checkerspot butterflies and streaked horned larks (Pearson and Altman 2005, p. 13). The historical fire frequency on prairies has been estimated to be 3 to 5 years (Foster 2005, p. 8).

The result of fire suppression has been the invasion of the prairies and oak woodlands by native and nonnative plant species (Dunn and Ewing 1997, p. v; Tveten and Fonda 1999, p. 146), notably woody plants such as the native Douglas-fir and the nonnative Scot's broom, and nonnative grasses such as
Arrhenatherum elatus
(tall oatgrass) in Washington and
Brachypodium sylvaticum
(false brome) in the Willamette Valley of Oregon. This increase in woody vegetation and nonnative plant species has resulted in less available prairie habitat overall and habitat that is avoided by Taylor's checkerspot butterflies and streaked horned larks (Tveten and Fonda 1999, p. 155; Pearson and Hopey 2005, pp. 2, 27; Olson 2011a, pp. 12, 16).

Most butterflies avoid densely forested areas, as they are unable to generate enough heat from their own metabolism to provide them with the heat and energy they need to fly in shaded conditions. Streaked horned larks prefer areas that afford long sight lines and have low vegetation; both of

which are impeded by the presence of trees.

On tallgrass prairies in midwestern North America, fire suppression has led to degradation and the loss of native grasslands (Curtis 1959, pp. 296, 298; Panzer 2002, p. 1297). On northwestern prairies, fire suppression has allowed Douglas-fir to encroach on and outcompete native prairie vegetation for light, water, and nutrients (Stinson 2005, p. 7). On JBLM alone, over 16,000 acres (6,477 ha) of prairie has converted to Douglas-fir forest since the mid-19th century (Foster and Shaff 2003, p. 284). Where controlled burns or direct tree removal are not used as a management tool, this encroachment will continue to cause the loss of open grassland habitats for Taylor's checkerspot butterfly.

Restoration in some of the south Puget Sound grasslands in Washington has resulted in temporary control of Scot's broom and other invasive plants through the careful and judicious use of herbicides, mowing, grazing, and fire. Fire has been used as a management tool to maintain native prairie composition and structure and is generally acknowledged to improve the health and composition of grassland habitat by providing a short-term nitrogen addition, which results in a fertilizer effect to vegetation, thus aiding grasses and forbs as they resprout.

Unintentional fires ignited by military training burns patches of prairie grasses and forbs on JBLM on an annual basis. These light ground fires create a mosaic of conditions within the grassland, maintaining a low vegetative structure of native and nonnative plant composition, and patches of bare soil. Because of the topography of the landscape, fires create a patchy mosaic of areas that burn completely, some areas that do not burn, and areas where consumption of the vegetation is mixed in its effects to the habitat. One of the benefits to fire in grasslands is that it tends to kill regenerating conifers, and reduces the cover of nonnative shrubs such as Scot's broom, although Scot's broom seed stored in the soil can be stimulated by fire (Agee 1993, p. 367). Fire also improves conditions for many native bulb-forming plants, such as
Camassia
sp. (camas) (Agee and Dunwiddie 1984, p. 367). On sites where regular fires occur, such as on JBLM, there is a high complement of native plants and fewer invasive species. These types of fires promote the maintenance of the native short-statured vegetation communities (Severns and Warren 2008, p. 476) favored by Taylor's checkerspot butterflies for larval and nectar food resources. Fire management to maintain or restore native vegetation is essential to maintaining suitable habitat for Taylor's checkerspot butterfly, but the timing of the management activity is important, as improperly-timed actions can destroy larvae, eggs, or adult butterflies.

Management practices such as intentional burning and mowing require expertise in timing and technique to achieve desired results. If applied at the wrong season, frequency, or scale, fire and mowing can be detrimental to the restoration of native prairie species. For example, during a prescribed fire event that was implemented in an adjacent training area on JBLM in late summer 2011, fire occurred in an area containing Taylor's checkerspot butterfly habitat that was under a protection agreement. This burn was inconsistent with the prescribed burn plan and eliminated a large area of the Taylor's checkerspot butterfly larval host and nectaring plants on the 91st Division Prairie. Excessive and high intensity burning can result in a lack of vegetation or encourage regrowth to nonnative grasses. Where such burning has occurred over a period of more than 50 years on the artillery ranges of the JBLM, prairies are covered by nonnative forbs and grasses instead of native perennial bunchgrasses (Tveten and Fonda 1999, pp. 154-155).

Taylor's Checkerspot Butterfly.
On JBLM, the 91st Division Prairie is frequently ignited through routine training exercises involving ordnance, which prevents invasive shrubs and nonnative grasses and native Douglas-fir from encroaching onto the prairie, and preserves the high quality of habitat (larval and nectar food plants) for Taylor's checkerspot butterflies and the generally good condition of the prairie. Vegetation at this site remains in an early successional stage that is dominated by native grasses and forbs, such as
Balsamorhiza deltoidea
(deltoid balsamroot), which is an important Taylor's checkerspot butterfly nectar plant. Fires on grassland (prairie) habitat generally have low fuel content and produce regular, short duration fires (Agee 1993, p. 354; Chappell and Kagan 2001, p. 43), which restricts the establishment of invasive plants and encroaching trees and helps to maintain native grasses and forbs. Swales and overall topographic heterogeneity prevent the entire grassland landscape from being consumed by fire, as grasslands fires tend to be patchy in their distribution creating a mosaic of conditions. Nonnative grasses have invaded many sites occupied by Taylor's checkerspot butterflies (Severns and Warren 2008, p. 476). Several hundred acres (more than 40 ha) of tall oatgrass is currently encroaching upon the largest Taylor's checkerspot butterfly population in Washington (JBLM's 91st Division Prairie).

Bald habitats at the Forest Service and WDNR sites where Taylor's checkerspot butterflies are found were formerly forested. These areas appear to have been colonized by Taylor's checkerspot butterfly shortly after they were cleared. At the time the trees were harvested from each of these balds they were reforested with conifers to comply with the Washington State Forest Practices rules. The establishment and growth of the conifers, and the establishment and expansion of
Acer macrophyllum
(bigleaf maple),
Holodiscus discolor
(oceanspray), and other shrubs has resulted in shaded habitat which have replaced areas that the Taylor's checkerspot butterfly is currently using. Sites that currently have Taylor's checkerspot butterflies present will quickly become unsuitable if trees and shrubs are not removed and if the site is not managed specifically for the long-term conservation of the Taylor's checkerspot butterfly or the maintenance of bald habitat. This is the case for several balds recently occupied by Taylor's but no longer supporting the species, including Bald Hills NAP in south Puget Sound, and Highway 112 and Striped Peak on the Olympic Peninsula.

A large portion of the existing Taylor's checkerspot butterfly habitat on Denman Island in Canada resulted from timber harvest. After the area was logged, Taylor's checkerspot butterflies colonized the disturbed area from nearby suitable habitat. Currently,
Alnus rubra
(red alder), bigleaf maple, and Douglas-fir trees are expanding onto the site, which will directly threaten the butterfly habitat there (COSEWIC 2011, p. 18). As the forest becomes reestablished on the property, it will shade and outcompete the host plants for Taylor's checkerspot butterfly for space, water, light, and nutrients. The population of Taylor's checkerspot butterfly is expected to decline significantly within the next 10 years at the Canada site if the habitat on Denman Island is not managed for the species (COSEWIC 2011, p. 31).

Streaked Horned Lark.
Prior to the construction of dams on the Columbia River, annual flooding and scouring likely created nesting and wintering habitat for streaked horned larks on sandy islands and beaches along the river's edge (Stinson 2005, p. 67). Once the dams were in place,
Salix
spp. (willows),
Populus trichocarpa
(black cottonwood), and other vegetation established broadly on the sandbars and

banks (Rogers 2000, pp. 41-42), resulting in unsuitable habitat for larks. Loss of these habitats may have been partially ameliorated by the formation of dredge spoil islands that have been established as part of the U.S. Army Corps of Engineers' (Corps) shipping channel maintenance (Stinson 2005, p. 67).

Streaked horned larks currently use sand islands in the lower Columbia River for both breeding and wintering habitat; these islands are a mosaic of Federal, State, and private lands, but there are no management or conservation plans in place to protect larks or these important habitats. The Corps has a dredging program to maintain the navigation channel in the Columbia River. In 2002, the Corps established a deeper navigation channel in the river, a regular maintenance dredging program, and a plan for disposition of dredge material on the islands in the lower Columbia River (U.S. Fish and Wildlife Service (USFWS) (USFWS 2002b, pp. 1-14). In this plan, the Corps addressed the disposition of dredge material in the lower Columbia River, which has the potential to both benefit and harm streaked horned larks, depending on the location and timing of deposition. Recent studies by Anderson (2010a, p. 29) on the islands in the lower Columbia River have shown that fresh dredge material stabilizes and develops sparse vegetation suitable for lark nesting approximately 3 years after deposition, and can be expected to remain suitable for approximately 2 years before vegetation becomes too dense. Thus, deposition of dredge material can be both a tool for habitat creation and a threat, as deposition of dredge material at the wrong time (e.g., during the nesting season) can destroy nests and young or degrade suitable habitat.

Destruction of occupied lark habitat through the deposition of dredge materials has been documented several times on the lower Columbia River islands (Stinson 2005, p. 67; Pearson and Altman 2005, p. 11; Pearson
et al.
2008, p. 14). In 2006, dredge spoils were deposited on Whites Island while larks were actively nesting. All nests at this site were apparently destroyed (Pearson 2012a, pers. comm.). This site had at least 21 nests and 13 territories during the 2005 nesting season (Pearson
et al.
2008, p. 21). In a similar situation on Rice Island, singing males were observed on Rice Island in June 2000, but dredge spoil was placed on the site in July 2000, which destroyed nesting habitat during the breeding season (MacLaren 2000, p. 3). In 2004 on Miller Sands Spit, the Army Corps of Engineers deposited dredge material on lark breeding habitat, which likely resulted in nest failure (Pearson and Altman 2005, p. 10). The Corps has recently began working with the Center for Natural Lands Management to coordinate dredge spoil depositions with timing of lark breeding season (Anderson 2011,
in litt.
).

Dredge spoil deposition also creates habitat for Caspian terns (
Sterna caspia
), a native bird species that nests in very large numbers in the lower Columbia River; these large terns have been shown to eat substantial numbers of salmon smolts, and the reduction of predation by terns on young salmon has been the focus of an interagency effort for the past decade (Lyons
et al.
2011, p. 2). One aspect of the effort to reduce the numbers of terns in the lower Columbia River has been a program to discourage tern nesting on Rice Island by planting vegetation and placing barrier fencing on open sandy habitats; these measures have also reduced habitat available to larks on the island and are ongoing (Stinson 2005, p. 73; Roby
et al.
2011, p. 14).

There is ample evidence that larks respond positively to habitat management that simulates natural processes. From 2001 through 2004, JBLM used nonbreeding season mowing and controlled burns to control Scot's broom (Pearson and Hopey 2005, p. 30). The September 2004 burns resulted in increased lark abundance and a dramatic vegetative response on 13th Division Prairie; relative to the control sites, late summer fire in 2006 resulted in increased use of the burned areas by larks immediately after the fires, and in the breeding season following the fires (Pearson and Hopey 2005, p. 30).

Throughout the year, streaked horned larks use areas of bare ground or sparse vegetative cover in grasslands. These grasslands may be native prairies in the Puget lowlands, perennial or annual grass seed fields in the Willamette Valley, or the margins of airport runways throughout the range of the species. All of these habitats receive management to maintain desired structure: prairies require frequent burning or mowing to prevent succession to woodlands; agricultural fields are mowed at harvest or burned to reduce weed infestations; airports mow to maintain low-stature grasses around airfields to minimize attracting hazardous wildlife. Burning and mowing are beneficial to larks in that they maintain the habitat structure required by the bird, but these activities can also harm larks if the activities occur during the breeding season when nests and young are present (Pearson and Hopey 2005, p. 29). In the nesting seasons from 2002 to 2004, monitoring at the Puget lowlands sites (Gray Army Airfield, McChord Field, and Olympia Airport) documented nest failure of 8 percent of nests caused by mowing over the nests, young, and adults (Pearson and Hopey 2005, p. 18). Habitat management to maintain low-stature vegetation is essential to maintaining suitable habitat for streaked horned larks, but the timing of the management is important, as improperly-timed actions can destroy nests and young.

Military Training

Populations of Taylor's checkerspot butterflies and streaked horned larks occurring on JBLM are exposed to differing levels of training activities on the base. The DOD's proposed actions under `Grow the Army' (GTA) include stationing 5,700 new soldiers, new combat service support units, a combat aviation brigade, facility demolition and construction to support the increased troop levels, additional aviation, maneuver, and live fire training (75 FR 55313, September 10, 2010). The increased training activities will affect nearly all training areas at JBLM resulting in an increased risk of accidental fires, and habitat destruction and degradation through vehicle travel, dismounted training, bivouac activities, and digging. While training areas on the base have degraded habitat for these species, with implementation of conservation measures, these areas still provide habitat for Taylor's checkerspot butterfly and streaked horned lark.

Taylor's Checkerspot Butterfly.
Military training on JBLM has resulted in direct mortality of Taylor's checkerspot butterflies and destruction of Taylor's checkerspot butterfly habitat. Vehicle use and soldier foot traffic can crush larvae and damage larval host plants. These actions disrupt intact prairie plant communities by disturbing vegetation and exposing soils, directly introducing invasive plant seeds carried in on tires or boots, and accelerating the rate of establishment of invasive grasses or other nonnative plants that are light-seeded and easily blown onto a site from adjacent areas, like
Cirsium
spp. (thistles),
Senecio
spp. (groundsel),
Chrysanthemum leucanthemum
(oxeye daisy). For example, in January 2009 an exercise occurred that did not follow the documented training plan, which would have restricted vehicles to established roads in order to protect sensitive habitat. Instead vehicles moved haphazardly across an area known to be occupied by Taylor's checkerspot butterflies and streaked horned larks.

Approximately 67 ac (27 ha) of prairie were repeatedly traversed by eight wheeled armored personnel carriers known as Strykers. DOD staff later estimated that up to 37.5 ac (15 ha) were highly disturbed (Gruhn 2009, pers. comm.), with much of this acreage scraped to bare soil (Linders 2009b, entire). This impact would have directly affected overwintering larvae by crushing larvae and destroying the larvae plants used by Taylor's checkerspot butterflies.

Taylor's checkerspot butterfly counts were the lowest ever recorded at this site during the following spring (Linders 2009a, entire; Randolph 2009, p. 4; Thomas 2009, pers. obs). Prior to the butterfly flight season in May 2009, the three brigades of Strykers were dispatched away from JBLM and the prairies were not used for Stryker training during the spring of 2009 or 2010, which corresponds to the butterfly flight period. This training break allowed Range 74-76 of the 91st Division Prairie to regenerate or recover the vegetative qualities associated with Taylor's checkerspot butterfly and streaked horned lark habitat. JBLM has subsequently coordinated with the Service to establish specific conservation measures regarding vehicle use within this training area. Military training also occurs on a specific portion of the 91st Division Prairie called Training Area 50 where Taylor's larvae have been translocated during spring 2009, 2010, and 2011, and at the proposed checkerspot translocation site at 13th Division Prairie.

Under the GTA initiative, more troops and vehicles will be stationed at JBLM; this is likely to result in increased pressure on Taylor's checkerspot butterfly habitat and larvae, particularly if the Army continues training on 91st Division Prairie. It is likely that a higher number of troops will equate to a higher number of individuals recreating on JBLM in places like Marion and Jackson prairies (this is further discussed under recreational impacts below).

Streaked Horned Lark.
Military training, including bombardment with explosive ordnance and hot downdraft from aircraft has been documented to cause nest failure and abandonment for streaked horned larks at Gray Army Airfield and McChord Field at JBLM (Stinson 2005, pp. 71-72). These activities harass and may kill some streaked horned larks, but the frequent disturbance also helps to maintain sparse vegetation and open ground needed for streaked horned lark nesting.

In the odd-numbered years since 2005, McChord Field has hosted a military training event known as the Air Mobility Rodeo. This international military training exercise is held at the end of July. This event includes aircraft, vehicles, and tents staged on or near lark nesting areas, although the majority of these activities take place on concrete hardstand areas (Geil 2010,
in litt.
). In even-numbered years, McChord Field hosts a public air show known as Air Expo, which is scheduled in mid-July. At the Air Expo, aerial events incorporate simulated bombing and fire-bombing, including explosives and pyrotechnics launched from an area adjacent to the most densely populated streaked horned lark nesting site at this location; these disturbances likely have adverse effects to fledglings of late nests (Stinson 2005, p. 72). Surveys in 2004 detected 31 pairs of streaked horned larks at McChord Field (Anderson 2011, p. 14). In 2006, the number of lark pairs at McChord Field had dropped by more than half to 14 pairs, and the number of lark pairs has remained low, with just 11 pairs detected in 2011 (Anderson 2011, p. 14). The Rodeo and Air Expo events are scheduled to take advantage of the good weather that typically occurs in the summer on the south Puget Sound; this timeframe also coincides with the streaked horned lark nesting season, and the disturbance may continue to cause nest failure and abandonment (Pearson
et al.
2005a, p. 18). During the airshows, tents, vehicles and concession stands are set up in the grassy areas along the runways used by streaked horned larks for nesting and thousands of visitors a day line the runways for viewing the shows.

Airports routinely implement a variety of approaches to minimize the presence of hazardous wildlife on or adjacent to airfields and to prevent wildlife strikes by aircraft. McChord Field uses falcons to scare geese and gulls off the airfield, and also uses two dogs for this purpose; the falcons and dogs are part of McChord Field's Integrated Bird/Wildlife Aircraft Strike Hazard program and are designed to minimize aircraft and crew exposure to potentially hazardous bird and wildlife strikes (Geil 2010,
in litt.
). The falcons and dogs cause streaked horned larks to become alert and fly (Pearson and Altman 2005, p. 12), which imposes an energetic cost to adults and could expose nests to predation. Portland International Airport uses a variety of hazing and habitat management tools to minimize wildlife hazards. Raptors and waterfowl pose the greatest danger to aircraft operations, but the airport's Wildlife Hazard Management Plan aims to reduce the potential for any bird strikes (Port of Portland 2009, pp. 5-6). Streaked horned larks are not known to nest near the runways at Portland International Airport, but foraging individuals from the nearby Southwest Quad could be harassed by the hazing program, which could impose resulting energetic costs.

JBLM has committed to restrictions both seasonally and operationally on military training areas, in order to avoid and minimize potential affects to the Taylor's checkerspot butterfly and streaked horned lark. These restrictions include identified non-training areas, seasonally restricted areas during breeding, and the adjustment of mowing schedules to protect these species. These conservation management practices are outlined in an operational plan that the Service has assisted the DOD in developing for JBLM (Thomas 2012, pers. comm.).

Restoration Activities

Management for invasive species and encroachment of conifers requires control through equipment, herbicides, and other activities. While restoration has conservation value for the species, management activities to implement restoration may also have direct impacts to the species that are the target of habitat restoration.

Taylor's Checkerspot Butterfly.
On occupied sites, Taylor's checkerspot butterflies are present throughout the year in some life cycle form. Restoration activities (application of herbicides, use of restoration equipment, and fire) can result in trampling, crushing and destruction of Taylor's checkerspot butterfly larvae and larval host plants. Mowing to reduce the cover and competition from woody species, if done at the wrong time of year, can crush larval host plants and nectar plants used by adult butterflies on a site.

Streaked Horned Lark.
The introduction of
Ammophila arenaria
(Eurasian beachgrass) and
A. breviligulata
(American beachgrass), currently found in high and increasing densities in most of coastal Washington and Oregon, has dramatically altered the structure of dunes on the outer coast (Wiedemann and Pickart 1996, p. 289). The tall leaf canopy of beachgrass creates areas of dense vegetation, which is unsuitable habitat for streaked horned lark nesting (MacLaren 2000, p. 5). Streaked horned larks require sparse, low-stature vegetation with at least 16-17 percent bare ground; areas invaded by beachgrass are too dense for streaked horned larks. The area suitable for streaked horned lark breeding on the Washington coast has decreased as a result of the spread of beachgrasses (Stinson 2005, p. 65; USFWS 2011a, p.

4-2). In a 10-year period (from 1977 to 1987) at Leadbetter Point on the Willapa National Wildlife Refuge, spreading beachgrass reduced the available nesting habitat for streaked horned larks by narrowing the distance from vegetation to water by 112 feet (34 meters) (WDFW 1995, p. 19). Since 1985, encroaching beachgrasses have spread to cover over two-thirds of Damon Point at Grays Harbor, another lark breeding site on the Washington coast (WDFW 1995, p. 19). At Damon Point, Scot's broom is also encroaching on lark habitat, reducing the area available for nesting (Pearson 2011,
in litt.
). On the Oregon coast, the disappearance of the streaked horned lark has been attributed to the invasion of exotic beachgrasses and the resultant dune stabilization (Gilligan
et al.
1994, p. 205).

Some efforts have been successful in reducing the cover of encroaching beachgrasses. The Service's Willapa National Wildlife Refuge has restored habitat on Leadbetter Point. In 2007, the area of open habitat measured 84 ac (34 ha); after mechanical and chemical treatment to clear beachgrass (mostly American beachgrass) and spreading oyster shell across 45 ac (18 ha), 121 ac (50 ha) of sparsely vegetated open habitat suitable for lark nesting was created (Pearson
et al.
2009, p. 23). The main target of the Leadbetter Point restoration project was the threatened western snowy plover (
Charadrius alexandrinus nivosus
), but the restoration actions also benefited the streaked horned lark. Before the restoration project, this area had just 2 streaked horned lark territori

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2012-24465. Public record. Not legal advice.