Endangered and Threatened Wildlife and Plants; Final Rule Determining Endangered Status for the Southwestern Willow Flycatcher

SUMMARY: The Fish and Wildlife Service (Service) determines the

southwestern willow flycatcher (Empidonax traillii extimus) to be an

endangered species under the authority of the Endangered Species Act of

1973, as amended (Act). The breeding range of this bird includes

southern California, southern Nevada, southern Utah, Arizona, New

Mexico, western Texas, southwestern Colorado, and extreme northwestern

Mexico. Within this region, the species is restricted to dense riparian

associations of willow, cottonwood, buttonbush, and other deciduous

shrubs and trees. This habitat was historically rare and sparsely

distributed and is currently more rare owing to extensive destruction

and modification. The southwestern willow flycatcher is endangered by

extensive loss of habitat, brood parasitism, and lack of adequate

protective regulations. This rule implements Federal protection

provided by the Act for the southwestern willow flycatcher. Designation

of critical habitat for the southwestern willow flycatcher is deferred

while the Service gathers further comments and reconsiders the prudence

of designation and the appropriate boundaries of any area to be

designated.

DATES: The listing of the southwestern willow flycatcher is effective

March 29, 1995. Comments on the designation of critical habitat may be

submitted until April 28, 1995.

ADDRESSES: The complete file for this rule is available for inspection,

by appointment, during normal business hours at Ecological Services

State Office, U.S. Fish and Wildlife Service, 2321 West Royal Palm

Road, Suite 103, Phoenix, Arizona 85021.

FOR FURTHER INFORMATION CONTACT: Sam F. Spiller or Robert M. Marshall

at the above address (Telephone 602/640-2720).

SUPPLEMENTARY INFORMATION:

Background

The southwestern willow flycatcher is a small bird, approximately

15 centimeters (cm) (5.75 inches) long. It has a grayish-green back and

wings, whitish throat, light grey-olive breast, and pale yellowish

belly. Two wingbars are visible; the eye ring is faint or absent. The

upper mandible is dark, the lower is light. The song is a sneezy

``fitz-bew'' or ``fit-za-bew,'' the call a repeated ``whitt.''

The southwestern willow flycatcher occurs in riparian habitats

along rivers, streams, or other wetlands, where dense growths of

willows (Salix sp.), Baccharis, arrowweed (Pluchea sp.), buttonbush

(Cephalanthus sp.), tamarisk (Tamarix sp.), Russian olive (Eleagnus

sp.) or other plants are present, often with a scattered overstory of

cottonwood (Populus sp.) (Grinnell and Miller 1944, Phillips 1948,

Phillips et al. 1964, Whitmore 1977, Hubbard 1987, Unitt 1987,

Whitfield 1990, Brown and Trosset 1989, Brown 1991, Sogge et al. 1993,

Muiznieks et al. 1994). Throughout the range of E. t. extimus, these

riparian habitats tend to be rare, widely separated, small and/or

linear locales, separated by vast expanses of arid lands. The

southwestern willow flycatcher has experienced extensive loss and

modification of this habitat and is also endangered by other factors,

including brood parasitism by the brown-headed cowbird (Molothrus ater)

(Unitt 1987, Ehrlich et al. 1992, Sogge et al. 1993, Muiznieks et al.

1994).

The southwestern willow flycatcher (Order Passeriformes; Family

Tyrannidae) is a subspecies of one of the ten North American

flycatchers in the genus Empidonax. The willow flycatcher and alder

flycatcher (E. alnorum) were once considered a single species, the

Traill's flycatcher (E. traillii). Some sources [American

Ornithologists' Union (AOU) 1983, McCabe 1991] treat E. traillii and E.

alnorum, and all their subspecies as a superspecies, the ``traillii

complex''. However, the two species are distinguishable by morphology

(Aldrich 1951), song type, habitat use, structure and placement of

nests (Aldrich 1953), eggs (Walkinshaw 1966), ecological separation

(Barlow and McGillivray 1983), and genetic distinctness (Seutin and

Simon 1988). The breeding range of the alder flycatcher generally

occurs north of the willow flycatcher's range.

The southwestern willow flycatcher is one of five subspecies of the

willow flycatcher currently recognized (Hubbard 1987, Unitt 1987,

Browning 1993) (Figure 1.). The breeding ranges of the widely

distributed E. t. traillii and E. t. campestris extend across the

northern United States and southern Canada, from New England and Nova

Scotia west, through northern Wyoming and Montana, and into British

Columbia. Hubbard (1987) and Unitt (1987) treated E. t. campestris as

synonymous with E. t. traillii, but Browning (1993) considered them

separate subspecies (Figure 1.). The subspecies E. t. adastus breeds

from Colorado west of the plains, west through the Great Basin States

and into the eastern portions of California, Oregon and Washington. The

breeding range of E. t. brewsteri extends from the central California

coast north, through western Oregon and Washington to Vancouver Island.

The breeding range of the southwestern willow flycatcher (E. t.

extimus) includes southern California, southern Nevada, southern Utah,

Arizona, New Mexico, and western Texas (Hubbard 1987, Unitt 1987,

Browning 1993). It may also breed in southwestern Colorado, but nesting

records are lacking. Records of probable breeding E. t. extimus in

Mexico are few and are restricted to extreme northern Baja California

del Norte and Sonora (Unitt 1987, Wilbur 1987).

BILLING CODE 4310-55-M

[[Page 10695]]

[GRAPHIC][TIFF OMITTED]TR27FE95.000

BILLING CODE 4310-55-C

[[Page 10696]]

The willow flycatcher subspecies are distinguished primarily by

subtle differences in color and morphology. Unitt (1987) noted that

these differences ``* * * are minor, but differ little in magnitude

from those distinguishing the species E. traillii from E. alnorum. In

Empidonax, small differences in morphology may mask large differences

in biology.''

The subspecies E. t. extimus was described by A.R. Phillips (1948)

from a collection by G. Monson from the lower San Pedro River in

southeastern Arizona. The taxonomy of E. t. extimus was critically

reviewed by Hubbard (1987), Unitt (1987), and Browning (1993). Hubbard

(1987) gave a qualified endorsement of the validity of E. t. extimus,

recommending continued examination of the taxonomy. Unitt (1987) found

that E. t. extimus was distinguishable from other willow flycatchers by

color, being paler, and morphology (primarily wing formula) but not

overall size. Browning (1993) also found that E. t. extimus was

distinguishable as a more pale-colored subspecies. The song dialect of

E. t. extimus may also be distinguishable from other willow

flycatchers. Rather than the crisp, sneezy ``fitz-bew'' of the

northerly subspecies, E. t. extimus sings a more protracted, slurred

``fit-za-bew,'' with a burry ``bew'' syllable (recordings by M. Sogge

and J. Travis). The subspecies E. t. extimus is accepted by most

authors (e.g., Aldrich 1951, Behle and Higgins 1959, Phillips et al.

1964, Bailey and Niedrach 1965, Oberholser 1974, Monson and Phillips

1981, Harris et al. 1987, Schlorff 1990, Harris 1991). Section 3(15) of

the Act and regulations at 50 CFR 424.02(k) defines the term

``species'' as any subspecies of fish or wildlife or plants, and any

distinct population segment of any vertebrate species which interbreeds

when mature. Based on the above information, the Service has determined

that E. t. extimus is eligible for protection under the Act.

The southwestern willow flycatcher nests in thickets of trees and

shrubs approximately 4-7 meters (m) (13-23 feet) or more in height,

with dense foliage from approximately 0-4 m (13 feet) above ground, and

often a high canopy cover percentage. The diversity of nest site plant

species may be low (e.g., willows) or comparatively high (e.g.,

mixtures of willow, buttonbush, cottonwood, boxelder, Russian olive,

Baccharis, and tamarisk). Nest site vegetation may be even- or uneven-

aged, but is usually dense and structurally homogeneous (Brown 1988,

Whitfield 1990, Sogge et al. 1993, Muiznieks et al. 1994).

Historically, E. t. extimus nested primarily in willows, buttonbush,

and Baccharis, with a scattered overstory of cottonwood (Grinnell and

Miller 1944, Phillips 1948, Whitmore 1977, Unitt 1987). Following

modern changes in riparian plant communities, E. t. extimus still nests

in native vegetation where available, but has been known to nest in

thickets dominated by tamarisk and Russian olive (Hubbard 1987, Brown

1988, Sogge et al. 1993, Muiznieks et al. 1994). Sedgwick and Knopf

(1992) found that sites selected as song perches by male willow

flycatchers (E. t. traillii/campestris) exhibited higher variability in

shrub size than did nest sites and often included large central shrubs.

Habitats not selected for either nesting or singing were narrower

riparian zones, with greater distances between willow patches and

individual willow plants. Nesting willow flycatchers of all subspecies

generally prefer areas with surface water nearby (Bent 1960, Stafford

and Valentine 1985, Harris et al. 1987), but E. t. extimus virtually

always nests near surface water or saturated soil (Phillips et al.

1964, Muiznieks et al. 1994). At some nest sites surface water may be

present early in the breeding season but only damp soil is present by

late June or early July (Muiznieks et al. 1994, M. Whitfield, Kern

River Research Center, in litt.-1993, J. and J. Griffith, Griffith

Wildlife Biology, in litt.-1993). Ultimately, a water table close

enough to the surface to support riparian vegetation is necessary.

Defining a minimum habitat patch size required to support a nesting

pair of E. t. extimus is difficult. Throughout its range, determining

the capability of habitat patches to support southwestern willow

flycatchers is confused by the species' rarity, unstable populations,

variations in habitat types, and other factors. However, the available

information indicates that habitat patches as small as 0.5 hectare (ha)

(1.23 acres) can support one or two nesting pairs. Sogge et al. (1993)

found territorial flycatchers in habitat patches ranging from 0.5 to

1.2 ha (1.23 to 2.96 acres). Two habitat patches of 0.5 and 0.9 ha

(1.23 and 2.2 acres) each supported two territories. Muiznieks et al.

(1994) also reported groups of territorial E. t. extimus in habitat

patches of approximately one to several hectares.

The nest is a compact cup of fiber, bark, and grass, typically with

feathers on the rim, lined with a layer of grass or other fine, silky

plant material, and often has plant material dangling from the bottom

(Harrison 1979). It is constructed in a fork or on a horizontal branch,

approximately 1-4.5 m (3.2-15 feet) above ground in a medium-sized bush

or small tree, with dense vegetation above and around the nest (Brown

1988, Whitfield 1990, Muiznieks et al. 1994).

The southwestern willow flycatcher is present and singing on

breeding territories by mid-May, although its presence and status is

often confused by the migrating individuals of northern subspecies

passing through E. t. extimus breeding habitat [D. Kreuper, Bureau of

Land Management (BLM), unpubl. data]. The southwestern willow

flycatcher builds nests and lays eggs in late May and early June and

fledges young in early to mid-July (Willard 1912, Ligon 1961, Brown

1988, Whitfield 1990, Sogge and Tibbitts 1992, Sogge et al. 1993,

Muiznieks et al. 1994). Some variation in these dates has been observed

(Carothers and Johnson 1975, Brown 1988, Muiznieks et al. 1994) and may

be related to altitude, latitude, and renesting.

The southwestern willow flycatcher is an insectivore. It forages

within and above dense riparian vegetation, taking insects on the wing

or gleaning them from foliage (Wheelock 1912, Bent 1960). It also

forages in areas adjacent to nest sites, which may be more open (M.

Sogge, National Biological Survey, pers. comm. 1993). No information is

available on specific prey species.

The migration routes and wintering grounds of E. t. extimus are not

well known. Empidonax flycatchers rarely sing during fall migration, so

that a means of distinguishing subspecies is not available (Blake 1953,

Peterson and Chalif 1973). However, willow flycatchers have been

reported to sing and defend winter territories in Mexico and Central

America (Gorski 1969, McCabe 1991). The southwestern willow flycatcher

most likely winters in Mexico, Central America, and perhaps northern

South America (Phillips 1948, Peterson 1990). However, the habitats it

uses on wintering grounds are unknown. Tropical deforestation may

restrict wintering habitat for this and other neotropical migratory

birds (Finch 1991, Sherry and Holmes 1993).

Breeding bird survey data for 1965 through 1979 combined the willow

and alder flycatchers into a ``Traill's flycatcher superspecies'',

because of taxonomic uncertainty during the 15-year reporting period.

These data showed fairly stable numbers in central and eastern North

America but strong declines in the West, the region including the range

of the southwestern willow flycatcher, and where the alder flycatcher

is absent (Robbins et al. 1986). [[Page 10697]]

Unitt (1987) reviewed historical and contemporary records of E. t.

extimus throughout its range, determining that it had ``declined

precipitously,'' and that ``although the data reveal no trend in the

past few years, the population is clearly much smaller now than 50

years ago, and no change in the factors responsible for the decline

seem likely.'' Data are now available that indicate continued declines,

poor reproductive performance, and/or continued threats for most

remaining populations (Brown 1991, Whitfield and Laymon, Kern River

Research Center, in litt. 1993, Sogge and Tibbitts 1992, Sogge et al.

1993, Muiznieks et al. 1994).

Previous Federal Actions

The Service included the southwestern willow flycatcher on its

Animal Notice of Review as a category 2 candidate species on January 6,

1989 (54 FR 554). A category 2 species is one for which listing may be

appropriate but for which additional biological information is needed.

After soliciting and reviewing additional information, the Service

elevated E. t. extimus to category 1 candidate status on November 21,

1991 (56 FR 58804). A category 1 species is one for which the Service

has on file substantial information to support listing, but for which a

proposal to list has not been issued because it is precluded at present

by other listing activity.

On January 25, 1992, a coalition of conservation organizations

(Suckling et al. 1992) petitioned the Service, requesting listing of E.

t. extimus as an endangered species under the Act. The petitioners also

requested emergency listing and designation of critical habitat. On

September 1, 1992, the Service published a finding (57 FR 39664) that

the petition presented substantial information indicating that listing

may be warranted and requested public comments and biological data on

the species. On July 23, 1993, the Service published a proposal (58 FR

39495) to list E. t. extimus as endangered with critical habitat, and

again requested public comments and biological data on the southwestern

willow flycatcher.

Summary of Comments and Recommendations

In the July 23, 1993, proposed rule (58 FR 39495) and associated

notifications, all interested parties were requested to submit comments

or information that might bear on whether to list the southwestern

willow flycatcher. The comment period was originally scheduled to close

October 21, 1993, then was extended to November 30, 1993. Appropriate

State agencies, county governments, Federal agencies, scientific

organizations, and other interested parties were contacted and

requested to comment. Newspaper notices inviting public comment were

published in the following newspapers; In California, Los Angeles

Times, L.A. Watts Times, Kern Valley Sun, and San Diego Union-Tribune;

in Arizona, Arizona Daily Sun, Arizona Republic, Tucson Daily Citizen,

White Mountain Independent, and Arizona Daily Star; in New Mexico,

Albuquerque Journal, Albuquerque Tribune, Santa Fe New Mexican,

Carlsbad Current-Argus, Silver City Daily Press; in Nevada, Las Vegas

Sun; in Colorado, Durango Herald; in Utah, Daily Spectrum; and in

Texas, El Paso Times. The inclusive dates of publications were August

31 through September 13, 1993, for the initial comment period and

October 28 through November 5, 1993, for the public hearings and

extension of public comment period.

The Service held six public hearings. Because of anticipated

interest in the proposed rule, the Service announced its intention to

hold at least three public hearings. In response to requests from the

public, three additional hearings were scheduled. A notice of the

hearing dates and locations was published in the Federal Register on

October 18, 1993 (58 FR 53702). Approximately 424 people attended the

hearings. About 17 people attended the hearing in Tucson, Arizona; 27

in Flagstaff, Arizona; 10 in Las Cruces, New Mexico; 12 in Albuquerque,

New Mexico; 350 in Lake Isabella, California; and 8 in San Diego,

California. Transcripts of these hearings are available for inspection

(see ADDRESSES).

A total of 3,102 written comment letters were received at the

Service's Ecological Services State Office in Arizona: 264 supported

the proposed listing; 2,650 opposed the proposed listing; and 188

expressed neither support nor opposition, but either commented on

information in the proposed rule, provided additional information, or

were non-substantive or irrelevant to the proposed listing.

Oral or written comments were received from 62 parties at the

hearings: 8 supported the proposed listing; 40 opposed the proposed

listing; and 14 expressed neither support nor opposition but provided

additional information, or were non-substantive or irrelevant to the

proposed listing.

In total, oral or written comments were received from 31 Federal

and State agencies and officials, 17 local officials, and 3,116 private

organizations, companies, and individuals. All comments received during

the comment period are addressed in the following summary. Comments of

a similar nature are grouped into a number of general issues.

Issue 1: The American Ornithologists' Union (AOU) did not list E.

t. extimus in its latest Checklist of North American Birds; Unitt

(1987) could not distinguish E. t. extimus by color or morphology;

genetic analysis is necessary to distinguish subspecies; significant

disagreement exists among scientists regarding taxonomy, for example,

McCabe (1991) did not recognize E. t. extimus; the willow flycatcher

subspecies, in fact the North American Empidonax flycatcher species are

too difficult to distinguish to make it reasonable to list subspecies

of those species; hybridization of the willow flycatcher subspecies

occurs; subspecies are not worth listing; E. t. extimus is a subspecies

of a very common species; E. t. extimus is not worth listing because it

is one of nine common species in the genus Empidonax; this subspecies

and subspecies in general are of minor ecological value; their loss

would be unimportant; there is little value in preserving rare species/

subspecies; and historical taxonomic questions may confuse population

trend information.

Service Response: The Service has determined that E. t. extimus is

a valid taxon. The Service relies on the most current and authoritative

data available in making decisions regarding the validity of species,

subspecies, or distinct vertebrate population segments. These data

include articles published in professional journals, agency reports,

and other unpublished data provided by researchers. For the

southwestern willow flycatcher, the Service reviewed this information

and found a majority opinion that E. t. extimus is a valid subspecies.

Authorities who critically examined the taxonomy of E. traillii and

recognized E. t. extimus include Phillips (1948), Aldrich (1951),

Hubbard (1987), Unitt (1987), and Browning (1993). Other authorities

accepting the subspecies include Behle and Higgins (1959), Phillips et

al. (1964), Bailey and Niedrach (1965), Oberholser (1974), Monson and

Phillips (1981), Harris et al. (1987), Schlorff (1990), Whitfield

(1990), Brown (1991), Harris (1991), Western Foundation for Vertebrate

Zoology in litt. 1993, University of California in litt. 1993. The AOU

(1983) did not list subspecies of any bird, including the willow

flycatcher, in its 1983 Checklist of North America Birds. However, this

does not indicate a lack of recognition of E. t. extimus, or for the

concept of subspecies. The preface to the 1983 Checklist states ``The

Committee [[Page 10698]] strongly endorses the concept of the

subspecies * * * and we wish to make it clear that the omission of

separate listings of subspecies in this edition is not a rejection of

the validity or utility of this systematic category * * *.''

The Service noted McCabe's (1991) consideration of the willow and

alder (E. alnorum) flycatchers as a single species, and his reluctance

to recognize willow flycatcher subspecies. McCabe (1991) provides a

thorough review of the history of E. alnorum and E. traillii taxonomy,

and the questions of ecological, morphological, and song-type

distinction on which this taxonomic evaluation has been based. However,

the Service agrees with Sedgwick's (1993) comments and McCabe's own

observation that McCabe (1991) contrasts with the majority opinion

regarding taxonomy of the willow and alder flycatchers.

After examining 305 study skins, Unitt (1987) found that while four

subspecies (E. t. traillii, E. t. adastus, E. t. brewsteri, and E. t.

extimus) could be tentatively separated by the ``75 percent rule''

using overall size (wing and tail lengths and their ratios to one

another), these criteria were not satisfactorily conclusive. However,

he found that the subspecies could be satisfactorily distinguished,

under the ``75 percent rule,'' using color, wing formula (relative

lengths of primary wing feathers), or both. Browning (1993) examined

270 specimens and found that all four subspecies, and a fifth (E. t.

campestris) were distinguishable by color.

The Service acknowledges that taxonomy of E. traillii races

continues to pose questions and may be revised in the future. The

Service has determined that E. t. extimus is a sufficiently distinct

entity to be listed under the Act at the very least as a distinct

vertebrate population [50 CFR Sec. 424.02(k)]. However, the Service

accepts the majority opinion that E. t. extimus is a valid subspecies

and lists it as such.

The Service considers taxonomic distinctness in assigning

priorities for species listings, but not in determining whether or not

to list species. The Act authorizes listing of species, subspecies, or

distinct population segments, all of which have ecological

significance.

Issue 2: The southwestern willow flycatcher is not a riparian

obligate species. It also occurs in open prairie woodlots, dry and

brushy pastures, and brushy fields or slopes. No surveys of dry

habitats have been done to prove riparian obligacy. The southwestern

willow flycatcher does not ``invariably'' nest near surface water.

Service Response: The Service is unaware of any study, report, or

species account that describes E. t. extimus as anything but a riparian

obligate. No commenter provided data, studies, or reports indicating

that E. t. extimus nests outside riparian habitats. Several commenters

cited field guides which describe the willow flycatcher (all

subspecies) as occurring ``* * * in drier situations (than the alder

flycatcher) * * *'' (Peterson 1990), ``* * * on brushy slopes * * *''

(Robbins et al. 1983), and ``* * * dry, brushy upland pastures * * *''

(National Geographic Society 1990). The Service believes that field

guide species accounts do not constitute the best available scientific

information on biology, ecology or habitat requirements. Field guide

accounts tend to be brief and generalized, and in this case represent

habitat use of other willow flycatcher subspecies, which occur in more

mesic regions. Similarly, Barlow and McGillivray's (1983) description

of willow flycatchers (E. t. campestris/traillii) selecting ``* * * a

more xeric upland habitat * * *'' in Ontario, Canada, is not considered

relevant to habitat selection of E. t. extimus in the desert Southwest.

In the wetter climates of the north, upper midwest, and northeast,

habitat conditions of moist soil or surface water, supporting thickets

of deciduous shrubs and trees, are not restricted to riparian areas.

However, in the arid Southwest where E. t. extimus occurs, these

conditions are limited to riparian areas, usually in profound contrast

to the adjacent and prevailing desert conditions. Various authors

(e.g., King 1955) have noted that while willow flycatchers may nest

away from riparian areas in the north and east, in arid regions (the

ranges of E. t. brewsteri and E. t. extimus particularly) the species

is restricted to riparian habitats. Regarding the presence of surface

water during the breeding season, new information was provided

indicating that some nest sites have surface water in close proximity

early in the breeding season, which recedes underground by the end of

the breeding season. At these sites, the water table remains at least

high enough to sustain riparian vegetation. The Service is unaware of

any surveys performed in non-riparian habitats specifically to verify

the absence of nesting E. t. extimus. However, the Service relied on

local, State, and regional species accounts of distribution and habitat

use, none of which describe occurrence outside of riparian habitats.

Issue 3: The loss and modification of southwestern riparian habitat

is overstated, poorly documented, and does not constitute a threat to

the flycatcher; the statement that 90 percent loss of riparian habitat

has occurred is inaccurate and an exaggeration; riparian habitat has

not decreased, but increased as a result of diversions, irrigation,

etc; habitat has increased, not decreased, in local area(s) over the

past 20 years; riparian regeneration is approaching 1,000 percent in

southeastern Arizona; Hastings and Turner (1965) show that cottonwood

riparian habitat has increased in southeastern Arizona; the upper San

Pedro River is recovered, not ``unsuitable and unoccupied'' as the

Service claimed; because tamarisk has increased, and E. t. extimus uses

tamarisk, tamarisk invasion does not constitute modification of

habitat, but expansion of habitat; population declines in the past 20

years are concurrent with improved riparian habitats, so no correlation

exists between trends in habitat and populations; the proposal fails to

support claims that urban development, agriculture, and livestock

grazing are harmful to the flycatcher.

Service Response: The Service has determined that the documentation

of loss and modification of southwestern riparian habitats, cited in

this final rule, is adequate. Regarding the ``90 percent loss and

modification'' statement, the proposed rule stated that ``* * * as much

as 90 percent * * *'' (emphasis added) has been lost or modified. The

actual percentage lost or modified is not expected to be consistent

across the region, but should vary with elevation, rainfall, geographic

area, relative size of drainage system, and severity of impacts. Loss

and modification may be lesser at higher elevations, where

precipitation is greater and evaporation less. In most major lower

elevation desert riparian systems, loss or modification may in fact be

near 100 percent, e.g., the lower Colorado, lower Gila, lower Rio

Grande, and lower Salt Rivers. Because ``modification'' includes

alterations in flow regimes, channel confinement, changes in water

quality, and floristic makeup of riparian systems, the Service believes

it is not a misrepresentation to state that up to 90 percent of

southwestern riparian ecosystems have been lost or modified.

Commenters stating that riparian habitat has not decreased, but

increased as a result of diversions and irrigation, presented no

supporting information. The Service recognizes that some diversions,

particularly unmaintained irrigation ditches, sometimes support

riparian vegetation. However, the Service believes diversion and

irrigation result in a net loss of riparian habitat.

[[Page 10699]] Where riparian vegetation becomes established along

irrigation systems, it is often cleared away at regular intervals.

Where it is not, it is sometimes because an artificially created

riparian/wetland habitat is being maintained as mitigation or

compensation for loss of natural riparian habitat elsewhere.

The Service recognizes that in some local areas in recent decades,

riparian habitat has been rehabilitated or increased, not decreased.

However, the Service accepts the consensus of literature cited in this

rule that the overall trend continues to be one of habitat loss.

Hastings and Turner (1965) and Bahre (1991) noted that riparian

habitats were already significantly altered by the turn of the last

century. Hastings and Turner (1965) also noted that all major

watercourses in southern Arizona suffered entrenchment and became more

ephemeral in flow in approximately 1890. Land use practices that had

already affected riparian habitats in this Arizona-Mexico border region

included livestock grazing, woodcutting, and water diversion; climatic

changes may also have contributed. The differences between the historic

and more recent photographs show some riparian recovery, concurrent

with reductions in livestock stocking levels from their highs in the

late 1800's. No data, or elaboration, were presented to support

statements that riparian regeneration is approaching 1000 percent in

southeastern Arizona.

As this final rules discusses, E. t. extimus sometimes nests in

tamarisk, but does so at lower densities, and apparently at lower

success rates than in native vegetation (Hunter et al. 1988, Sogge et

al. 1993, Muiznieks et al. 1994). Therefore, tamarisk invasion likely

represents replacement of native habitat with lower-quality habitat,

rather than an increase in habitat availability. Only in a few unique

situations does tamarisk truly represent ``new'' habitat. For example,

in the Grand Canyon flycatchers nest in a ``new'' riparian habitat,

dominated by tamarisk (Carothers and Brown 1991). This new riparian

habitat became established in the historic flood-scour zone of the

Colorado River, after construction of Glen Canyon Dam eliminated annual

scouring floods. However, flycatchers nest in this area in low numbers

(Brown 1991, Sogge and Tibbitts 1992, Sogge et al. 1993) and have low

nesting success. It is noteworthy that by forming Lake Powell, Glen

Canyon Dam also inundated habitat in Glen Canyon. The southwestern

willow flycatcher was described as a common nester in Glen Canyon prior

to inundation (Behle and Higgins 1959, Behle 1985), indicating that

this historic habitat was of higher quality than the new habitat in

Grand Canyon.

Issue 4: The flycatcher has always been a rare bird, so its rarity

now is no change from historical situations; historical specimens are

few, indicating the bird was always rare; population data are

insufficient to show decline; population data are suspect, developed by

parties with agendas of land control/acquisition; the flycatcher is not

declining in all areas; historical taxonomic questions may confuse

population trend information; accuracy or existence of population trend

data for the last 50 years is questionable; population sampling

techniques were not discussed; these could bias trend studies;

population data are incomplete; the proposal relies on data reflecting

loss of habitat rather than comprehensive population trend analysis;

there are no recent collections of E. t. extimus from southern Arizona

riparian areas.

Service Response: The Service agrees that the flycatcher has

probably always been sparsely distributed, as a function of the sparse

distribution of its wetland habitat in a predominantly xeric region.

However, sparse distribution and rarity are not necessarily equivalent.

At individual locales the flycatcher may occur in considerable numbers,

as indicated by Herbert Brown's collection of 36 nests near Yuma in

1902, and the persistence of several populations of considerable

numbers (30-40 pairs) in relatively small areas like the Kern River

Preserve in California (Harris et al. 1986, Whitfield 1990). Although

E. t. extimus habitat is rare, where it is present nesting pairs may

occur in relatively high densities. This phenomenon has caused some

authors to describe E. t. extimus as something of a colonial nester

(e.g., Unitt 1987).

Regarding the lack of historic or recent specimens available from

various parts of the bird's range, the Service notes that specimen

collection is largely a function of collecting activity, not simple

presence of the subject.

The Service agrees that, as with many non-game species, population

trend data are incomplete. No wide scale, and few local studies have

been funded or undertaken to track this species through time.

Comprehensive, long-term population data are not necessarily required

for making listing determinations. Rather, these decisions often rest

upon data on loss and modification of habitat and other threats, which

are reasonably assumed to result in population declines. In many cases,

population declines are inferred from decline in habitat availability.

However, in this and other listing determinations, the Service seeks to

measure such inference against whatever population trend data are

available. Regarding concerns over sources of these data, the Service

endeavors to verify accuracy and credibility of data. The reports

published by government agencies, academic institutions, and

professional journals on which this determination is based are accepted

as credible. To interpret population trends in the light of changing

taxonomic status, the Service considered all information for willow

flycatchers in the current range of E. t. extimus to be relevant.

Issue 5: Livestock grazing is not a threat to E. t. extimus or its

habitat; Montgomery et al. (1985) found 53 singing birds in a grazed

area in New Mexico; on Marine Corps Base Camp Pendleton, E. t. extimus

is increasing where sheep graze; nest disturbance by cattle is

unsubstantiated; southwestern flora evolved with large grazing

ungulates; the proposed rule lacks examples of flycatcher status

improving with reduction in livestock or improved livestock management;

E. t. extimus is not improving in areas with no grazing; the proposed

rule equates any livestock grazing with overgrazing, and fails to

distinguish between overgrazing and well-managed grazing; proper

livestock management is compatible with healthy riparian habitat; some

level of livestock grazing is compatible with/necessary for healthy

riparian ecosystems; willows are brush, which cattle don't eat, but

cattle are blamed for both brush encroachment and brush destruction;

cattle trample stream banks, which allows water to escape, creating

more riparian habitat; livestock grazing prevents urbanization of land,

which would have a greater impact on riparian habitats.

Service Response: The proposed and final rules discuss overuse by

livestock as a threat to E. t. extimus, through impacts on riparian

habitat. The Service recognizes that what constitutes ``overuse''

varies with differing riparian ecosystems, elevation, type of

livestock, seasonality of use, and other factors. The Service believes

that some livestock grazing regimes are likely to be found compatible

with rehabilitation and maintenance of E. t. extimus habitat.

Montgomery et al. (1985) did not determine whether the willow

flycatchers they detected on grazed land were resident E. t. extimus or

migrating individuals of other subspecies. Further, neither grazing

intensity nor nesting [[Page 10700]] success were quantified, so that

no correlations can be made. On Camp Pendleton, increases in E. t.

extimus were concurrent with livestock (sheep) grazing but also with an

extensive cowbird trapping program (Griffith and Griffith 1993).

Finally, as discussed in this rule, examples exist of E. t. extimus

(and other E. traillii subspecies) numbers and habitat increasing as a

result of grazing reductions or other improvements in livestock

management.

The Service recognizes that southwestern riparian ecosystems

evolved with native grazing ungulates (e.g., deer and elk). However,

domestic livestock do not forage, herd or move in the same manner as

native species. Further, elk occur at higher elevations of the

Southwest, and are absent from the lowland river systems that

constitute the majority of E. t. extimus habitat.

Issue 6: Timber harvesting is not a threat to the flycatcher's

riparian habitat.

Service Response: The proposed rule noted that the petitioners

claimed timber harvest caused watershed changes which could result in

damage to riparian habitats through increasing intensity and frequency

of floods. The petitioners presented no specific information on this

claim. A number of experimental treatments on Southwestern forested

watersheds have demonstrated increased peak and flood flows as a result

of timber harvest (Tecle 1991). The degree to which timber harvesting

has affected riparian habitats inhabited by the willow flycatcher,

however, has not been quantified and is unknown. The Service did not

implicate timber harvesting in the proposed rule as a major cause of

riparian habitat loss. Rather, it pointed to that activity as one of

many factors potentially responsible for riparian habitat loss and

modification. Pending new information demonstrating otherwise, the

Service still considers timber harvesting a potential threat to

riparian habitat through loss and modification. However, the Service

does not believe that this threat exists rangewide, nor does it believe

that timber harvesting alone is responsible for riparian habitat loss

or the endangered status of the southwestern willow flycatcher.

All causal factors will be addressed in the recovery planning

process, and through the Act's section 7 consultation process, through

which Federal agencies will be responsible for evaluating the effects

of activities such as timber harvest on the flycatcher's riparian

habitat.

Issue 7: Water impoundments have been beneficial, not detrimental;

fluctuating flows below dams are not detrimental, in fact have

increased riparian habitat (Glen Canyon Dam resulted in creation of

riparian habitat in Grand Canyon); impoundments protect habitat by

preventing catastrophic floods; the proposal had inadequate discussion

of water impoundments as threat.

Service Response: As discussed elsewhere in this final rule, water

impoundments have a variety of effects on riparian habitats. The

Service has determined that, with respect to E. t. extimus, the net

effect of these influences is negative. For example, Glen Canyon Dam

eliminated massive annual scouring floods in the Grand Canyon. This

resulted in the development of a new riparian zone dominated by

tamarisk (Carothers and Brown 1991). However, flycatchers nest there in

very low numbers and with low nesting success (Brown 1991, Sogge and

Tibbitts 1992, Sogge et al. 1993). In contrast, E. t. extimus was

described as a common nester in Glen Canyon (Behle and Higgins 1959,

Behle 1985), prior to its inundation by Lake Powell.

Issue 8: Comments concerning the ecology of cowbirds and cowbird

parasitism included the following: Breeding Bird Survey (BBS) data

indicate that cowbirds have declined, not increased; the claim that

cowbirds are associated with livestock is not supported; cowbirds are

associated with deer and elk, not cows; the cowbird threat is a natural

one; there is inconclusive evidence that cowbird increases are directly

connected with livestock grazing; cowbird parasitism of E. t. extimus

is known in areas without livestock grazing (e.g., Grand Canyon, Kern

River); there is no correlation between livestock grazing in riparian

areas and cowbird parasitism; Taylor (1986) showed that cowbirds were

most abundant in areas with long-term livestock exclusion; because

flycatchers and cowbirds are positively associated (they tend to occur

together), flycatchers can coexist with cowbirds; there is inconclusive

evidence that cowbird parasitism is responsible for declines in nesting

success; cowbirds have increased as a result of increases in bird

feeders, campgrounds, etc. and increases in wintering food/habitat; the

proposed rule cited no studies that documented cowbird parasitism of E.

t. extimus; citations regarding parasitism of other species are

irrelevant. Section 4(a)(1)(E) of the Act allows listing species

because of ``* * * natural or manmade factors affecting its continued

existence * * *.''

Service Response: Cowbird numbers appear to be declining only in

the northeastern United States and southeastern Canada. Through the 27

years of the BBS, cowbird populations have remained fairly stable, with

a small increase in the 1970's, small decrease in the 1980's, and

slight increase in recent years; however, the West has experienced a

marked population increase over the last five years (Wiedenfeld 1993).

The association of cowbirds with domestic livestock is detailed in

the sources cited in this final rule. The Service has neither found nor

been provided information indicating that cowbirds are associated with

deer or elk. Other factors, including habitat fragmentation and urban/

suburban feeding, are likely to have contributed to increases in

cowbirds. These causal factors will be important to address in the

section 7 consultation process and the development of recovery actions.

However, it is the threat of parasitism, regardless of cause, that in

part necessitates listing.

Where high parasitism rates are found in E. t. extimus nesting

locations in areas with no livestock grazing at the nest site, there

have been livestock nearby that provide feeding sites in close enough

proximity to facilitate cowbird parasitism. Cowbirds may disperse up to

7 kilometers (km) from their daily feeding/roosting sites to areas with

host species (Rothstein et al. 1984). At the Kern River Preserve, the

riparian habitat supporting E. t. extimus is not grazed, but the

immediately adjacent lands are. Similarly, although livestock grazing

does not occur in Grand Canyon National Park, open range grazing and an

introduced bison herd occur on adjacent lands. Further, cowbirds

concentrate at pack animal corrals at various points within the

National Park (Johnson and Sogge 1993). Thus, flycatcher habitat may be

ungrazed but still be affected by cowbirds, by having livestock

concentrations nearby to serve as cowbird feeding sites.

Cowbirds and E. t. extimus are positively associated because

cowbirds require, and therefore associate with, prospective hosts. The

Service finds that extensive information indicates cowbird parasitism

negatively affects the southwestern willow flycatcher. This information

includes specific examples of parasitism of E. t. extimus, cited in

this rule, and examples of the effects of cowbird parasitism on other

rare species of limited habitat. Recent information continues to

document high parasitism rates for E. t. extimus (Sogge et al. 1993,

Muiznieks et al. 1994), and increases in flycatcher reproduction or

populations, concurrent with reductions in cowbird numbers (Griffith

and Griffith 1993, M. Whitfield in litt.--1993). [[Page 10701]]

Issue 9: Tamarisk is not an invader species, but a successional

stage, becoming established on recently-scoured areas; livestock do eat

tamarisk for its salt content; the Service needs to clarify the

positive and negative characteristics of tamarisk; tamarisk increases

habitat availability, in fact provides high-quality bird habitat.

Service Response: The Service found no information, and was not

provided any information by commenters, indicating that tamarisk is

primarily a successional stage vegetation type, rather than an invasive

exotic. This final rule presents an updated discussion of tamarisk

ecology, supported by additional literature references. The Service

concurs with the consensus among published authorities that tamarisk is

an invasive, usually dominant exotic plant, not a successional species.

Commenters that stated livestock eat tamarisk for its salt content

provided no supporting information. The Service's understanding of the

literature is that cattle prefer native species over tamarisk for

forage.

As discussed in this rule, E. t. extimus has been documented

nesting in tamarisk at elevations above approximately 625 m (2000

feet). Rather than attempt to present criteria here for when tamarisk

eradication presents a threat or a positive recovery action, the

Service will address this issue on a case-by-case basis through the

section 7 consultation process with other Federal agencies. This will

allow Federal agencies the flexibility to consider individual cases in

the light of the specific circumstances surrounding each one.

Although Brown and Trosset (1989) suggested that tamarisk provided

an ``ecological equivalent'' to native vegetation, they qualified this

statement. They noted that their study involved small sample sizes, and

that their methods differed from Whitmore's (1975, 1977), which was

their basis for comparison with native riparian habitats. Further,

Brown and Trosset (1989) noted that this ``ecological equivalent''

function may be most significant where tamarisk became established

where no native riparian vegetation existed previously (e.g., the

Colorado River in Grand Canyon).

Issue 10: Herbert Brown's collection of 36 nests with eggs from the

lower Colorado River, in 1900 and 1902, indicates overcollection for

science may have caused declines.

Service Response: The effects of Brown's collections on populations

over 90 years ago are unknown. These effects may have been significant.

However, Brown's collections themselves may suggest that populations at

that time could sustain such collecting pressure. The origin of Brown's

collections from several specific locales suggests that E. t. extimus

was an abundant nesting bird in the area of the confluence of the Gila

and Colorado rivers. Collection of 36 nests would have impacted

reproduction alone, only for 1902, when all but one of the nests was

collected. Considering continued habitat loss, and increasing cowbird

populations since 1902, the Service does not believe that Brown's

collection of 36 nests with eggs in 1900 and 1902 significantly affects

E. t. extimus populations in 1995. However, the Service believes that

current flycatcher populations are unlikely to be able to sustain

collecting pressures like Brown's activities of 1902. In 1993,

extensive surveys of the region of Brown's collections located only

four to five territories (Muiznieks et al. 1994).

Issue 11: Drought has impacted habitat.

Service Response: The Service recognizes that extended droughts are

likely to have impacted E. t. extimus through habitat reduction. This

natural phenomenon and human-induced habitat impacts may exacerbate one

another's effects on E. t. extimus habitat.

Issue 12: Predators such as snakes, hawks, ravens, grackles, and

domestic cats are threats to E. t. extimus.

Service Response: The Service agrees that these constitute

potential predators of songbirds, including E. t. extimus. While

predation would not normally be expected to be a major threat to the

flycatcher, its populations may be so low currently that they cannot

withstand normal predation. Further, several of these types of

predation may be facilitated by habitat alteration or other human

actions. Therefore, the Service will address predation in recovery

planning, and other Federal agencies should consider the effects of

their actions on some of these forms of predation.

Issue 13: Hikers, elk, deer, and beaver are threats to flycatcher

nests and habitat; listing would cause restrictions on fishing and

water recreation.

Service Response: No information was provided to support statements

that hikers constitute a threat to E. t. extimus. This rule briefly

discusses possible impacts of recreation on E. t. extimus and its

habitat. These impacts are expected to be primarily effects on

vegetation through soil compaction, clearing vegetation, and creating

trails. Because E. t. extimus is not a timid species, disturbance is

expected to be an impact only when continuous intrusive activities take

place near habitat, or when recreation takes place within or adjacent

to the nest stand. Because nest stands tend to be very dense, virtually

impenetrable thickets, often with swampy conditions, recreational

impacts are not expected to occur often.

Elk and deer use riparian habitats for foraging, but generally

behave differently than domestic livestock. They tend not to occur in

large concentrations and remain in riparian areas for long periods like

domestic cattle. The Service is aware that elk can impact riparian

systems when their numbers reach high levels. However, elk are lacking

from the majority of southwestern willow flycatcher habitats, because

these riparian areas occur at lower elevations than elk. Beaver cut and

use willow and cottonwood, but may also be important in creating quiet-

water riparian habitats by damming smaller and steeper creeks.

Issue 14: The presence of unoccupied habitat indicates that E. t.

extimus is not currently habitat limited.

Service Response: As discussed in this rule, the Service has

determined that E. t. extimus has suffered extensive habitat loss,

which is complicated by the current low number of flycatchers, and

reduction of reproductive output due to brood parasitism by brown-

headed cowbirds. The current existence of apparently suitable habitat

that is not occupied by E. t. extimus more likely indicates that its

numbers are too low to fill all available habitat. Further, habitat

exists in isolated, fragmented patches. With low population numbers and

inhibited reproduction, E. t. extimus may be unable to maintain local

populations, much less be able to disperse and colonize unoccupied

locales.

Issue 15: Cowbird parasitism is the main threat to E. t. extimus,

not habitat loss; cowbird control is the primary recovery need, not

habitat protection; cowbird trapping would eliminate the need for

designating critical habitat; the Service should implement and fund

cowbird control programs instead of listing.

Service Response: The Service has determined that cowbird

parasitism is one of several primary threats to E. t. extimus, which

also includes the loss and modification of habitat. Cowbird parasitism

and loss and modification of habitat are interrelated. Cowbird

parasitism is a function not just of cowbird abundance, but also

habitat quality. Potential host species in degraded, fragmented habitat

are more susceptible to nest parasitism than those nesting in larger

tracts of dense, contiguous habitat. Cowbird parasitism

[[Page 10702]] will probably remain an imminent threat until habitat

rehabilitation is accomplished. The Service acknowledges that cowbird

control should be an immediate, high priority recovery action. However,

cowbird control is a ``stop-gap'' action. Rehabilitating riparian

habitat to make E. t. extimus and other riparian birds less susceptible

to cowbird parasitism will be necessary for a long-term solution.

Ultimately, the ranking of threats in order of severity is not relevant

to the listing question. It is because a number of often interdependent

threats exist that listing E. t. extimus is necessary. Ranking threats

in order of severity and addressing them accordingly will be part of

the recovery process.

Issue 16: Willow flycatchers nesting in the northern States,

Alaska, and Canada are subspecies other than E. t. extimus. The

boundaries of the breeding range of E. t. extimus should be expanded to

include the Santa Ynez River in California, and the Green and Colorado

River systems in west-central Utah; E. t. extimus does not occur in

Utah, Colorado, or the Carson National Forest in northern New Mexico;

the willow flycatcher is common in the northern States, Alaska, Canada,

most of the U.S., Mexico and Panama; caution should be exercised in

defining range limits of the subspecies, including elevational limits.

Service Response: Two primary authorities (Unitt 1987, Browning

1993) provide the range limits of E. t. extimus identified in this rule

(see Figure 1). The Service also considered other information, such as

historical nesting records, habitat characteristics, and proximity to

neighboring populations of E. t. extimus or other willow flycatcher

subspecies. Using this information, the Service provisionally defines

the northwestern limit of the subspecies' range to be the Santa Ynez

River in California. Willow flycatchers nesting along the Santa Ynez

River occupy lowland riparian habitat similar to other coastal

California locations of E. t. extimus, and few willow flycatcher (i.e.,

E. t. brewsteri) nesting locales are known in coastal California for a

considerable distance north of the Santa Ynez River.

Browning (1993) found no evidence of intergrades between E. t.

extimus and E. t. adastus in Utah. The northern limit of E. t. extimus

in Utah is believed to correspond closely to the area comprising the

following counties: Garfield, Kane, San Juan, Washington, and Wayne.

This area takes in stretches of riverine riparian habitat in southern

Utah that have historical records of flycatchers and that still have

potential willow flycatcher habitat.

The Service recognizes that taxonomic questions may arise

concerning flycatchers occupying some high-elevation locales within the

range of E. t. extimus. Because the genetic relatedness of willow

flycatchers breeding at some high elevation areas, such as the White

Mountains of Arizona, may be substantial, willow flycatchers in those

locales should be considered E. t. extimus until further research

demonstrates otherwise. Protection of these breeding groups could be

critical for population recovery, immigration, and exchange of genetic

material within a highly-fragmented landscape.

Issue 17: It is inappropriate to use data from E. t. brewsteri and

E. t. adastus to support listing E. t. extimus; information cited on

livestock damaging nests comes from other subspecies.

Service Response: The Service carefully considered the propriety of

using information on other willow flycatcher subspecies in evaluating

the listing question for E. t. extimus. In applying such information,

the Service considered ecological similarities and dissimilarities

between the subspecies. The Service believes that data from other

subspecies are applicable in some cases, but not others. The Service

has identified which subspecies provided data sources throughout the

proposed and final rules. The phenomenon of livestock damaging nests

and/or contents through physical contact is known for willow flycatcher

subspecies other than E. t. extimus. This threat was noted to recognize

that the potential exists, where nests occur low enough in vegetation

or in other vulnerable locations, that livestock, humans, or other

animals may contact them or the nest plant.

Issue 18: Habitat in California was lost to urbanization, not

livestock; the proposed rule had inadequate discussion of urban and

suburban development as a threat; urban development is not a threat to

some populations.

Service Response: Loss and modification of the riparian habitat of

E. t. extimus is the result of numerous factors, discussed in depth in

this rule. Not all these factors have affected all riparian habitats,

and some rare habitats remain unaffected. Further, the degree to which

these factors influence riparian habitat varies across the landscape.

Urban and suburban development has certainly impacted some E. t.

extimus habitats. These impacts may result from direct encroachment and

channelization of riparian habitats, as in coastal southern California

and central Arizona. Urban and suburban development also increase

demands on river systems for water and hydropower. Thus, expanding

urban centers can result in dewatering or alteration of riparian

systems tens or hundreds of miles away. For example, the water and

power demands of Los Angeles, Phoenix and Las Vegas result in effects

on the Colorado River hundreds of miles from any of these cities.

Issue 19: The primary threat to E. t. extimus is loss of wintering

habitat in Central and South America, or other factors along migration

routes; the proposed rule contained insufficient information on

migration studies; protecting breeding grounds is not logical, because

E. t. extimus spends eight months of the year in migration or on

wintering grounds.

Service Response: Although tropical deforestation possibly may

restrict wintering habitat of the willow flycatcher, the best available

current information on the subject suggests otherwise. The limited data

on willow flycatcher wintering habitat indicates that this species uses

``* * * brushy savannah edges and second growth'' in Costa Rica (Stiles

and Skutch 1989); in Panama it has been documented in ``shrubby areas''

(Ridgely 1981); and in South America it has been documented in ``* * *

shrubby clearings, pastures, and lighter woodland'' or ``* * * on

islands with early successional growth'' (Ridgely and Tudor 1994).

Given existing land use practices in Central and South America, which

are characterized by conversion of old-growth forested habitat to

agricultural and second-growth habitats, few if any of the winter

habitat types in which willow flycatchers have been documented should

currently be in jeopardy.

Issue 20: The Service cannot define nesting habitat; habitat

requirements are poorly understood; the proposed rule's description of

nesting habitat is flawed and inadequate to direct management; the

minimum patch size necessary to support a nesting pair of E. t. extimus

is 1 to 1.5 hectares.

Service Response: The Service believes the proposed rule and this

final rule accurately compile and summarize the existing information on

E. t. extimus nesting habitat, and that information is sufficient to

identify, conserve, and recover the riparian ecosystem of which E. t.

extimus is a part. Habitat patches occupied by E. t. extimus vary

somewhat in size, floristic composition, vegetation structure, and type

of wetland. Therefore, the Service believes it is inappropriate and

inaccurate to [[Page 10703]] narrowly define suitable habitat in terms

of plants per unit area, vegetation density, specific plant community

composition, type and volume of surface water, and patch size. The

Service has no information to indicate inaccuracy or inadequacy of the

habitat description presented in this rule. Specifically regarding

patch sizes, one to two E. t. extimus pairs have been observed nesting

in habitat patches of 0.5 ha (Sogge et al. 1993, Sogge et al. unpubl.

1994 data); therefore 1.0 to 1.5 ha is not an accurate estimate of the

minimum patch size needed to support a single nesting pair.

Issue 21: Habitats used by nesting pairs differ from those used by

single, unmated, wandering, or migrant flycatchers; the latter face

minimal threats and are not essential to conservation of the species.

Service Response: The commenters provided no data supporting the

statement that habitats used by unpaired E. t. extimus differ from

nesting habitat, and the Service found no indication of this in the

available literature. Unmated, resident E. t. extimus have been found

in habitats identical to nearby habitats occupied by nesting pairs

(Sogge and Tibbitts 1992, Sogge et al. 1993). The Service believes that

single, unmated E. t. extimus also face threats of habitat loss, and

that conservation of these individuals is essential to the conservation

of the species, particularly at the low current numbers of flycatchers.

Issue 22: Listing constitutes single-species management that will

damage other species; E. t. extimus habitat is incompatible with

habitat needs of other listed and sensitive species, particularly the

spikedace and loach minnow.

Service Response: The purposes of the Act are to provide a program

for the conservation of threatened and endangered species and to

conserve the ecosystems upon which threatened and endangered species

depend. The Service believes that managing for E. t. extimus and other

listed riparian and aquatic species accomplishes this purpose, to the

mutual benefit of listed and nonlisted species alike. The intent of

this listing is to conserve and recover E. t. extimus and the riparian

and aquatic ecosystems of which it is a part.

The primary constituent elements of critical habitat described for

the spikedace (59 FR 10906) and loach minnow (59 FR 10898) are not in

conflict with the habitat requirements for the southwestern willow

flycatcher, and are not in conflict with the primary constituent

elements of its proposed critical habitat (58 FR 39495). The fishes

require ``a healthy, intact riparian community,'' which will also

benefit E. t. extimus and other riparian and aquatic species. The

spikedace, loach minnow, and E. t. extimus all require surface water

and/or a high water table, a low to moderate stream gradient, and

periodic flooding. The fishes specifically require a ``natural,

unregulated hydrograph,'' which the Service believes would also benefit

the flycatcher. These fish also require moderate to high bank

stability; maintenance of the riparian vegetation on which E. t.

extimus depends will provide such bank stability. The Service does not

view management for E. t. extimus, spikedace, and loach minnow as

mutually exclusive, but as mutually beneficial.

Issue 23: Floods regenerate habitat, they do not destroy it; floods

destroy habitat; floods, not livestock, caused much of riparian

degradation; the proposed rule is confusing and contradictory on the

role of floods as a threat or necessary ecological function.

Service Response: The proposed rule stated that ``Its habitat

rarity, and small, isolated populations make the remaining E. t.

extimus increasingly susceptible to local extirpation through

stochastic events such as floods * * *. In early 1993, catastrophic

floods in southern California and Arizona damaged or destroyed much of

the remaining occupied or potential breeding habitat. Historically,

these floods have always destroyed habitat but were also important

events in regenerating cottonwood-willow communities.''

It is important to note that E. t. extimus is threatened by

stochastic events like floods because of its current rarity and

isolated nature of populations. If the species existed at healthy

population levels, and if its riparian habitat were not greatly

reduced, these natural stochastic events would not constitute threats.

The 1993 flood events referred to were extraordinary in nature,

described regionally as 500-year floods. Therefore, they do not typify

flood events in the river systems involved. Further, while natural

flood events are expected to destroy some flycatcher habitat, they are

also crucial for regenerating natural riparian nesting habitat. In a

healthy system where riparian vegetation is abundant and the stream

channel is not eroded or destabilized, destruction and regeneration are

balanced and habitat is generally available. Only when riparian

vegetation is severely reduced and the stream channel and watershed are

destabilized are riparian and aquatic species threatened by the

natural, short-term habitat losses resulting from flooding.

Issue 24: To manage for E. t. extimus, the Service will enforce or

has proposed a fenced livestock-free corridor.

Service Response: The Service has neither proposed nor been

consulted regarding a fenced, livestock-free corridor established along

riparian areas on State, Federal, or private lands.

Issue 25: Beneficial land management practices should be recognized

and discussed; the proposed rule fails to acknowledge that some

habitats are protected from urban development.

Service Response: The Service recognizes that some management

practices are beneficial. Some practices have protected or improved

habitat, resulted in expanded populations, and/or improved

reproduction. The Service will look to these beneficial land management

practices as important examples in the recovery planning process.

However, in making a listing determination the Service must consider

the situation across the species' entire range. It is this overall

perspective that drives the listing decision. Although some nesting

groups of E. t. extimus may be safe, stable, or perhaps even

increasing, the Service has determined that overall the species is

endangered.

Issue 26: Existing regulatory mechanisms are adequate, including:

the Migratory Bird Treaty Act (MBTA); State listings for Arizona, New

Mexico, and California; section 404 of the Clean Water Act; Bureau of

Land Management and Forest Service policies; Executive Orders 11988 and

11990; protection of riparian habitat due to presence of other listed

species; private and/or cooperative management plans at local areas.

Service Response: The Service considered these regulatory

mechanisms and management plans, and determines that overall existing

regulatory mechanisms are insufficient to conserve and recover E. t.

extimus in the face of the primary threats of loss and modification of

habitat and cowbird parasitism. A full discussion of Federal and State

protection is found in this document under Factor D: ``Inadequacy of

existing regulatory mechanisms''.

The Service recognizes that some local management plans benefit and

conserve E. t. extimus and its habitat. Examples include management of

the Bureau of Land Management's San Pedro Riparian National

Conservation Area (SPRNCA) in Arizona, where six years of livestock

exclusion have resulted in significant restoration of riparian habitats

and increases in birds associated with habitats similar to E. t.

extimus (Krueper 1993). Willow [[Page 10704]] flycatchers have not yet

returned to their historical locations on the SPRNCA but may soon.

Habitat protection and cowbird management at The Nature Conservancy's

Kern River Preserve and on Marine Corps Base Camp Pendleton in

California have improved habitat and reduced brood parasitism pressures

for resident E. t. extimus (Griffith and Griffith 1993). Wetland

management at Bosque del Apache National Wildlife Refuge in New Mexico

is apparently sustaining a small population of flycatchers. While these

actions are beneficial, they provide for E. t. extimus only at several

locales. Further, long-term continuation of these management actions is

not assured.

Provisions of section 404 of the Clean Water Act do not

specifically protect E. t. extimus or its habitat, but do provide some

protection to the aquatic and riparian ecosystems of which it is a

part. Section 404 of the Clean Water Act also provides for mitigation

of destruction of these habitats, however, allowing even temporary

destruction of riparian habitat is not consistent with the immediate

conservation needs of E. t. extimus.

Issue 27: The Service did not use the best available scientific or

commercial information in making this determination; the Service

presented insufficient and inconclusive information to support listing;

the proposed rule used information which was general, incomplete, and

originated with other flycatcher subspecies; the proposed rule was

premature; the Service did not adequately solicit information and

public input; scientific, economic, biological, hydrological and

botanical data must support listing; how does the Service know the

scientific information supporting listing was right?

Service Response: The Service canvassed the published literature

regarding the taxonomy, ecology, and biology of the southwestern willow

flycatcher, and the threats to it and its habitat. Because numerous and

complex phenomena and processes were involved, this information ranged

from general (e.g., wide scale trends in riparian habitat) to very

specific (status of nesting groups). The Service believes it used the

best available information, and has determined that this information is

adequate to support listing. The Service evaluates sources before using

or discounting information. In general, the Service expects that

publications in peer-reviewed scientific journals, reports from land

and resource management agencies, and dissertations or reports from

academic or research institutions have undergone technical review.

Other information sources are considered more anecdotal, and the

Service seeks to confirm such information before using it.

Issue 28: The Service should comply with the National Environmental

Policy Act (NEPA) by completing an Environmental Impact Statement

(EIS), and comply with 40 CFR 1506 to reduce duplication between NEPA

and State and local requirements; the Service should comply with 40 CFR

1508.20 to compensate for producing substitute resources or

environments; the Service should engage in joint planning with local

governments under NEPA regulations.

Service Response: As noted in this final rule, the Service has

determined that an Environmental Assessment, as defined under the

authority of NEPA, need not be prepared for listing actions. A notice

outlining the Service's reasons for this determination was published in

the Federal Register on October 25, 1983 (48 FR 49244). Because of this

determination, an EIS also need not be prepared. Also because of this

determination, reduction of duplication between the NEPA process and

State and local agencies, and joint planning between those agencies and

the NEPA process, are rendered moot.

Issue 29: The proposed rule violates the Regulatory Flexibility

Act; no Regulatory Impact Analysis/Assessment as required under

Executive Orders 12291 and 12866 was completed; it also may be

inconsistent with the mandates of other agencies.

Service Response: Decisions on listing and reclassification under

the Act are made based on five factors defined in section 4(a)(1) of

the Act. These five factors are discussed in this rule, as they relate

to E. t. extimus. The Act requires the Service to consider only

scientific and commercial information relating to these five factors in

making listing determinations, not economic information. Economic

information is considered in designating critical habitat, which is not

part of this rule. Therefore, compliance with the Regulatory

Flexibility Act and Executive Orders 12291 and 12866 is not an issue

for this action, but will be addressed if a critical habitat

designation is made (H.R. Conf. Rep. No. 835, 97th Cong., 2d Sess. 20

(1982); accord, S. Rep. No. 418, 97th Cong., 2d Sess. 4 (1982)).

Where conservation and recovery of threatened and endangered

species is inconsistent with other mandates of Federal agencies,

processes under section 7 of the Act serve to evaluate projects arising

from those mandates, with regard to protection of listed species.

However, section 2(c) of the Act requires all Federal departments and

agencies to conserve listed species and further the purposes of the

Act.

Issue 30: The Service should complete a Takings Implications

Assessment prior to listing/designating critical habitat.

Service Response: The Service will complete a takings analysis for

any final designation of critical habitat in compliance with Executive

Order 12630 and the Attorney General's supplemental guidelines issued

June 30, 1988. In accordance with those guidelines and Interior

Department policy, this analysis will be completed after listing, not

as part of consideration of the listing determination itself.

Issue 31: Requests were received for local public hearings.

Service Response: The proposed rule stated that three public

hearings would be held. Because of many requests for additional

hearings, a total of six public hearings were held. Regulations at 50

CFR 424.16(c)(3) require the Service to hold one public hearing if

requested.

Issue 32: The time allowed for public comments was inadequate; the

proposal should have been subjected to peer review.

Service Response: The Service is required to accept public comments

for at least 60 days regarding proposals to list and/or designate

critical habitat (50 CFR 424.16(c)(2)). In this case the Service

initially announced a 90-day public comment period, then extended that

another 40 days for a total of 130 days (July 23, 1993 through November

30, 1993). Public comment periods and public hearings are the

mechanisms by which the Service receives input from all interested

parties, including scientific peer review.

Issue 33: Listing would require private property owners to consult

with the Service on their actions; listing and/or designating critical

habitat constitute take of private property rights; adverse

modification of critical habitat would be prohibited on private lands;

the Service failed to notify the affected public of the consequences of

adverse modification of critical habitat; listing and/or designating

critical habitat may affect civil rights.

Service Response: Listing does not require private property owners

to consult with the Service on actions which may affect a listed

species. However, section 7 of the Act does require Federal agencies to

consult on actions which they fund, permit, or carry out if those

actions may affect a listed species or adversely modify critical

habitat. Any potential take of private property will be analyzed in

compliance with Executive Order 12630 [[Page 10705]] (see Issue 30). As

discussed later (Issue 35), because critical habitat is not being

designated with this rule, comments regarding critical habitat will be

addressed during subsequent actions regarding critical habitat.

Issue 34: Requests were received to be on a mailing list for all

actions relating to this issue or to be provided personal notification

of a final decision.

Service Response: The Service tries to maintain mailing lists for

specific issues whenever possible. However, when large numbers of

parties request to be on such lists, it becomes logistically and

financially unfeasible to mail information to each party. This issue is

one of those, and the Service must rely to some degree on mass

communication forums like news releases, public notices in newspapers,

and publications in the Federal Register.

Issue 35: Numerous comments were received regarding critical

habitat.

Service Response: Critical habitat for E. t. extimus is not being

designated with this rule; therefore, the above issues are not

addressed here. Designation of critical habitat is being deferred while

the Service further considers the extent to which designation is

appropriate. Issues pertaining to this designation will be addressed

when a final decision is made with regard to the critical habitat

proposal.

Issue 36: Numerous comments were received regarding recovery of E.

t. extimus, including: the Service has no recovery plan for E. t.

extimus; the proposed rule failed to identify recovery goals for

habitat, flycatcher numbers, and flycatcher distribution; the proposed

rule failed to identify what actions will be used to achieve recovery;

a recovery plan should address control of cowbird parasitism, nest

damage by livestock, tamarisk eradication, wintering habitat,

monitoring populations, protection of public and private lands from

fire; cowbird parasitism cannot be addressed by listing and designating

critical habitat; cowbirds are not easily controlled without

sacrificing flycatchers and/or impacting habitat; the proposed rule

contained no livestock managing strategy; rotating livestock will allow

habitat enhancement/recovery; the factors affecting riparian habitats

are numerous and complex; failure to address all could be futile or

have damaging effects.

Service Response: Section 4(f) of the Act authorizes the Service to

develop and implement recovery plans for listed species, not species

that are proposed for listing. For E. t. extimus, this process

therefore begins with the effective date of listing. In accordance with

section 4(f)(B) of the Act the recovery plan process will address

actions necessary to achieve conservation and recovery of E. t.

extimus, will identify measurable criteria by which recovery (i.e., the

point at which protection under the Act is no longer necessary) can be

gauged, and will identify the time and costs required to achieve

recovery. The specific issues identified above will be considered in

developing a recovery plan, and that plan will be available for public

review and comment prior to adoption. Monitoring species is frequently

an element of recovery plans, and is also required by section 4(g) of

the Act for any species deemed to be recovered.

Issue 37: Several commenters questioned the motivations of the

petitioners in requesting the listing, and others apparently believed

the petitioners authored the listing proposal. Several commenters noted

that the petition contained inaccuracies, and therefore no listing

proposal should have resulted.

Service Response: The Service cannot speak for the petitioners'

motivations in requesting listing of E. t. extimus. The Service judged

the petition solely on the scientific information it contained.

Inaccuracies were found in the petition, but on the whole the Service

determined that it presented substantial information indicating that

listing may be warranted. The listing proposal was authored by the

Service, not the petitioners. The Service developed its proposal not

from the petition, but from information gained from journal

publications, agency reports, and the general public's responses to

several information solicitations. This status review process had

resulted in the Service designating E. t. extimus a category 1

candidate species prior to the petition being received. That

designation indicated that the Service had sufficient information to

support a listing proposal but did not publish a proposal immediately

because it was dealing with listing actions of higher priority.

Information presented by the petitioners that the Service did not

already possess was checked for accuracy; information that could not be

confirmed, or was found to be inaccurate, was not used.

Issue 38: The Service is required to purchase interest in land or

water for implementation of the Act; this violates the U.S.

Constitution.

Service Response: Section 5 of the Act directs the Secretary to use

land acquisition and other authorities of the Fish and Wildlife Act of

1956, as amended, the Fish and Wildlife Coordination Act, as amended,

and the Migratory Bird Conservation Act, as appropriate. The Secretary

is authorized, but not required, to acquire interest in land or water

to conserve threatened and endangered species. The Service does not

carry out these authorities in violation of the U.S. Constitution. The

Service does not acquire all lands designated as critical habitat for a

listed species, and does not develop critical habitat designations

based on land ownership or interest of landowners in purchasing or

selling properties. It is the Service's policy to acquire property only

on a voluntary basis from willing sellers.

Issue 39: Land use outside occupied/critical habitat will be

adversely impacted.

Service Response: Federal actions that take place outside occupied

habitat or critical habitat, but that may affect E. t. extimus, will be

subject to consultation between the action agency and the Service in

accordance with section 7 of the Act. Exclusively private actions are

unaffected by listing and/or designation of critical habitat, provided

they do not result in violation of section 9 of the Act (e.g., take of

the species).

Issue 40: Listing (regardless of critical habitat) will have

adverse impacts on local economy; economic impacts of listing were not

addressed; the Act requires the Service to consider impacts on other

wildlife species and social and economic impacts prior to listing.

Service Response: Consideration of economic effects is required for

designation of critical habitat. The Act requires that species listing

decisions be based solely on the best scientific and commercial

information available, which precludes consideration of social or

cultural impacts or impacts on other species. (See section 4(b)(1)(A)

of the Act). The Service anticipates no significant impacts on other

native wildlife species as a result of listing, with the probable

exception of the brown-headed cowbird.

Issue 41: Who initiated, performed, and paid for studies along the

Kern River?

Service Response: Reports on studies done on the Kern River were

published by Harris et al. (1986), Harris et al. (1987), Whitfield

(1990), and Harris (1991). Specific information on project

participants, funding sources, and cooperators can be found in those

sources. The Service understands that monitoring and cowbird control

are being continued by the Kern River Research Center and The Nature

Conservancy, with funding assistance from the State of California and

the Service. [[Page 10706]]

Issue 42: The Service should perform additional surveys before

listing.

Service Response: The Service is supporting continuing surveys to

detect additional E. t. extimus, to monitor known nest sites, and to

evaluate habitat presence, quality, and distribution. The Service

supports these surveys with funding to States in accordance with

section 6 of the Act, and through logistical and technical assistance

to other agencies and parties. Extensive surveys in New Mexico and

Arizona in 1993 located E. t. extimus in numbers that do not

significantly change the total population estimates made in the

proposed rule. These surveys also confirmed high levels of brood

parasitism by cowbirds. With low estimates of total flycatcher numbers

being validated by continuing surveys, the Service has determined that

sufficient information exists on the threats of habitat loss and

cowbird parasitism to justify listing.

Issue 43: The Service failed to consult adequately with private

interests, State, Federal, and local agencies prior to publishing the

proposed rule.

Service Response: The Service published public requests for

information on the status of E. t. extimus in the Federal Register when

it was designated a category 2 candidate species in January 1989, and

when it was designated a category 1 species in November 1991. The

Service supplemented these requests with general mailings soliciting

information, and information solicitations in professional

publications. Beyond these mechanisms, the Service is constrained by

funding limitations and citizens' suits such as Environmental Defense

Center, Inc. vs. Babbitt et al. IV 93-1848-R (C.D. Calif.), which was

brought to compel the Service to propose listing and designation of

critical habitat for the species, that preclude individually contacting

every interested party.

Issue 44: The parties who petitioned for listing should pay for

studies supporting their request.

Service Response: Regulations implementing section 4 of the Act,

specifically the petition process [50 CFR 424.14], do not require

petitioners to fund studies supporting their request. Listing

determinations are made if existing information is deemed sufficient to

make a determination. This information typically originates from a

variety of sources.

Issue 45: The southwestern willow flycatcher is abundant. There is

no need to list.

Service Response: The Service has determined that E. t. extimus is

rare, not abundant, faces serious threats to its continued existence,

and warrants listing as endangered. See discussion under Factor A: The

present or threatened destruction, modification, or curtailment of its

habitat or range.

Issue 46: The ``little'' willow flycatcher (E. t. brewsteri) is the

most common subspecies observed and collected in the Southwest.

Service Response: The abundance of collections of E. t. brewsteri

from within the breeding range of E. t. extimus is because E. t.

brewsteri migrates through the Southwest between its Pacific coastal

breeding range and wintering grounds in Central America. E. t.

brewsteri passes through riparian habitats in the breeding range of E.

t. extimus in spring and fall, but does not breed there.

Issue 47: There is no need to list E. t. extimus in areas where it

is doing well.

Service Response: The Service has determined that E. t. extimus is

endangered; local areas where the bird is relatively stable could only

be excluded from listing or classified as threatened if they

constituted distinct population segments [50 CFR 424.02(k)]. The

Service has not identified any distinct population segments of E. t.

extimus. Further, because the Service determines E. t. extimus to be

endangered, all existing habitat and local nesting concentrations are

deemed to be essential to the conservation and recovery of the species.

Protection of locales where the bird is doing relatively well may be

especially important for the conservation and recovery of E. t.

extimus.

Issue 48: Prey availability may be a limiting factor.

Service Response: The Service recognizes that food availability is

always a potential limiting factor in wildlife populations. It is

possible that reduction of riparian habitats not only reduced

vegetation for nesting, but reduced or altered the arthropod fauna

associated with surface water and extensive vegetation. Also, as noted

in this rule, some speculation exists that tamarisk provides a

substandard nesting habitat because it supports a significantly

different insect fauna than native vegetation. However, no information

was available to evaluate this factor directly for E. t. extimus.

Issue 49: Several comments were received that pertained to the

Service's management of the 90-day petition finding, including that the

90-day petition finding was late; that it is not the Service's role to

conduct a status review if information in a petition is lacking; and

that a 30-day comment period on the 90-day petition finding was

insufficient.

Service Response: The Service acknowledges that its finding on the

listing petition was published after 90 days, however, the Act (section

4(b)(3)(A) states that the [Service] shall, to the maximum extent

practicable, make a petition finding within 90 days (emphasis added).

Because the petition was found to present substantial information

indicating that the petitioned action may have been warranted, the

Service continued a status review after this finding, in accordance

with 50 CFR 424.14(b)(3). There are no requirements for the Service to

open a formal comment period regarding a 90-day petition finding. The

Service did so in this case to solicit additional information on E. t.

extimus. In reaching its 12-month petition finding, the Service

considered all information received within the 30-day period

identified, and information received for several months thereafter.

Issue 50: E. t. extimus should be listed as threatened, not

endangered.

Service Response: The Service carefully evaluated the status of E.

t. extimus and has determined that it meets the definition of an

endangered species, not a threatened species. As stated in the proposed

rule, (58 FR 39495) threatened status would not be appropriate because

the large historic habitat loss already has caused extirpation

throughout a significant portion of the species' range. Population

numbers are extremely low, and a variety of threats are serious and

imminent.

Issue 51: Restrictions on rural livestock grazing will cause

ranching to become nonviable, and the land will be converted by

suburban development, which is a greater threat to E. t. extimus than

overgrazing.

Service Response: The conversion of lands from livestock grazing to

suburban development is hypothetical and therefore cannot drive the

Service's determination on this issue. Much of the livestock grazing

that may be affected by this rule takes place on Federal lands.

Therefore, conversion to suburban development would require land

exchanges or sales. These actions, if they were determined to affect E.

t. extimus, would require consultation under section 7 of the Act.

Regardless, prioritization of threats should be undertaken in the

recovery, rather than listing, process.

Issue 52: The proposed rule fails to consider changing ecological

factors: drought, migration patterns, nesting habits, and climatic

changes. [[Page 10707]]

Service Response: The Service recognizes that populations of E. t.

extimus are likely to fluctuate naturally in response to various

ecological factors. However, the Service believes that declines in

habitat availability and increased exposure to cowbird parasitism have

caused population reductions beyond the scale of natural fluctuations.

Fluctuations in response to nonanthropogenic phenomena are likely to

continue, but the current population levels are so low that these

natural phenomena may be sufficient to cause local extirpations.

Issue 53: Restrictions associated with listing would be in conflict

with Kern County's General Plan.

Service Response: Under section 4 of the Act, the Service considers

only scientific and commercial information relating to the five listing

factors outlined in section 4(a)(1) and discussed with respect to E. t.

extimus in this rule. Therefore, conflicts with local plans were not

considered in making this determination. However, the Service strives

to pursue conservation and recovery of listed species in cooperation

with State and local authorities, and seeks to minimize conflicts.

Issue 54: Listing and critical habitat designations will adversely

affect flood control measures, some authorized by the Federal Emergency

Management Agency and other Federal and State regulations; the proposed

rule failed to consider flood accommodation needs, channelization, and

clearing vegetation.

Service Response: Flood control measures virtually always involve a

Federal agency, through funding, permitting, and/or other action.

Therefore, flood control measures that may affect E. t. extimus would

undergo consultation under section 7 of the Act. Section 7 and its

implementing regulations have provisions for emergency consultations,

and for actions within presidentially declared disaster areas.

Issue 55: Government agencies are responsible for many impacts to

riparian areas; campgrounds, fish hatcheries, and some district offices

are located in riparian areas.

Service Response: The Service acknowledges that some Federal

actions are in part responsible for the threats facing E. t. extimus.

As a result of listing, those Federal actions will be subject to

consultation under section 7 of the Act to evaluate and minimize the

effects of those actions.

Issue 56: The Service does not acknowledge receipt of comments on

listing, and probably does not read them.

Service Response: The Service does not routinely acknowledge

receipt of each letter commenting on listing proposals. The number of

letters in this case made it logistically and financially impossible to

acknowledge each one. However, all letters were read, and their issues

addressed either here or elsewhere in this final rule. All comment

letters and transcripts of public hearings are retained in the

permanent file on this species and are available for public inspection.

Issue 57: Protecting flycatcher habitat may restrict mosquito

control, which is important for control of encephalitis and other

mosquito-borne diseases.

Service Response: Where such control involves a Federal action,

mosquito and disease control actions may be subject to consultation

under section 7(a)(2) of the Act, which would evaluate but not

necessarily restrict or significantly modify the project. Ultimately,

section 7(e) of the Act allows exemptions to the requirements of

section 7(a)(2).

Summary of Factors Affecting the Species

After a thorough review and consideration of all information

available, the Service has determined that the southwestern willow

flycatcher should be classified as an endangered species. Procedures

found at section 4(a)(1) of the Act and regulations implementing the

listing provisions of the Act (50 CFR Part 424) were followed. A

species may be determined to be an endangered or threatened species due

to one or more of the five factors described in section 4(a)(1). These

factors and their application to the southwestern willow flycatcher

(Empidonax traillii extimus) are as follows:

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

of its Habitat or Range

Large scale losses of southwestern wetlands have occurred,

particularly the cottonwood-willow riparian habitats of the

southwestern willow flycatcher (Phillips et al. 1964, Carothers 1977,

Rea 1983, Johnson and Haight 1984, Katibah 1984, Johnson et al. 1987,

Unitt 1987, General Accounting Office (GAO) 1988, Bowler 1989, Szaro

1989, Dahl 1990, State of Arizona 1990, Howe and Knopf 1991). Changes

in riparian plant communities have resulted in the reduction,

degradation, and elimination of nesting habitat for the willow

flycatcher, curtailing the ranges, distributions, and numbers of

western subspecies, including E. t. extimus (Gaines 1974, Serena 1982,

Cannon and Knopf 1984, Klebenow and Oakleaf 1984, Taylor 1986, Unitt

1987, Schlorff 1990, Ehrlich et al. 1992).

Dahl (1990) reviewed estimated losses of wetlands between 1780 and

the 1980's in the Southwest: California is estimated to have lost 91

percent, Nevada 52 percent, Utah 30 percent, Arizona 36 percent, New

Mexico 33 percent, and Texas 52 percent. As much as 90 percent of major

lowland riparian habitat has been lost or modified in Arizona (State of

Arizona 1990). Franzreb (1987) noted that ``[B]ottomland riparian

forests are the most highly modified of natural landscapes in

California.''

Loss and modification of southwestern riparian habitats have

occurred from urban and agricultural development, water diversion and

impoundment, channelization, livestock grazing, off-road vehicle and

other recreational uses, and hydrological changes resulting from these

and other land uses. Rosenberg et al. (1991) noted that ``it is the

cottonwood-willow plant community that has declined most with modern

river management.'' Loss of the cottonwood-willow riparian forests has

had widespread impact on the distribution and abundance of bird species

associated with that forest type (Hunter et al. 1987, Hunter et al.

1988, Rosenberg et al. 1991).

Overuse by livestock has been a major factor in the degradation and

modification of riparian habitats in the western United States. These

effects include changes in plant community structure and species

composition, and relative abundance of species and plant density. These

changes are often linked to more widespread changes in watershed

hydrology (Rea 1983, General Accounting Office 1988) and directly

affect the habitat characteristics critical to E. t. extimus. Livestock

grazing in riparian habitats typically results in reduction of plant

species diversity and density, especially of palatable broadleaf plants

like willows and cottonwood saplings, and is one of the most common

causes of riparian degradation (Carothers 1977, USDA Forest Service

1979, Rickard and Cushing 1982, Cannon and Knopf 1984, Klebenow and

Oakleaf 1984, GAO 1988, Clary and Webster 1989, Schultz and Leininger

1990).

Increases in abundance of riparian bird species have followed

reduction, modification, or removal of cattle grazing. Krueper (1993)

found the following increases in birds associated with cottonwood-

willow habitat on Arizona's San Pedro River four years after the

removal of livestock: yellow warbler, 606 percent; common yellow-

throat, 2,128 percent; yellow-breasted [[Page 10708]] chat, 423

percent. Bock et al. (1993) found that 40 percent of the riparian bird

species they examined, including the willow flycatcher (various

subspecies), were negatively affected by livestock grazing. Increases

in willow flycatcher numbers (various subspecies) have followed

reduction, modification, or removal of cattle grazing. Taylor (1986)

found a negative correlation between recent cattle grazing and

abundance of numerous riparian birds, including the Great Basin willow

flycatcher (E. t. adastus). In an area ungrazed since 1940, his bird

counts were five to seven times higher than comparable plots where

grazing was terminated in 1980. Taylor and Littlefield (1986) found

higher numbers of Great Basin willow flycatchers correlated with

minimal or nonexistent livestock grazing. Klebenow and Oakleaf (1984)

listed the Great Basin willow flycatcher among bird species that

declined from abundant to absent in riparian habitats degraded in part

by overgrazing. Schlorff reported willow flycatchers returning to Modoc

County, California, several years after removal of livestock grazing

(pers. comm. cited in Valentine et al. 1988). Knopf et al. (1988) found

that, during the summer, Great Basin willow flycatchers were present on

winter-grazed pastures, but were virtually absent from summer-grazed

pastures.

The Service believes that documentation of livestock impacts on

other willow flycatcher subspecies is relevant to E. t. extimus,

because linear riparian habitats in the arid range of E. t. extimus are

especially vulnerable to fragmentation and destruction by livestock. As

shady, cool, wet areas providing abundant forage, they are

disproportionately preferred by livestock over the surrounding xeric

uplands (Ames 1977, Valentine et al. 1988, A. Johnson 1989). Harris et

al. (1987) believed that termination of grazing along portions of the

South Fork of the Kern River in California was responsible for

increases in riparian vegetation and, consequently, nesting E. t.

extimus. Suckling et al. (1992) noted that most of the areas still

known to support E. t. extimus have low or nonexistent levels of

livestock grazing. More recent surveys (Muiznieks et al. 1994) have

found E. t. extimus in areas with livestock grazing; however, these

occur in widely dispersed, small groups whose nesting success is

largely unknown, and where livestock grazing intensity and seasonality

are also unknown.

Another likely factor in the loss and modification of southwestern

willow flycatcher habitat is invasion by the exotic tamarisk. Tamarisk

(also called saltcedar) was introduced into western North America from

the Middle East in the late 1800's as an ornamental windbreak and for

erosion control. It has spread rapidly along southwestern watercourses,

typically at the expense of native riparian vegetation, especially

cottonwood/willow communities. Although tamarisk is present in nearly

every southwestern riparian community, its dominance varies. It has

replaced some communities entirely, but occurs at a low frequency in

others.

The spread and persistence of tamarisk has resulted in significant

changes in riparian plant communities. In monotypic tamarisk stands,

the most striking change is the loss of community structure. The

multilayered community of herbaceous understory, small shrubs, middle-

layer willows, and overstory deciduous trees is often replaced by one

monotonous layer. Plant species diversity has declined in many areas,

and relative species abundance has shifted in others. Other effects

include changes in percent cover, total biomass, fire cycles, thermal

regimes, and perhaps insect fauna (Kerpez and Smith 1987, Carothers and

Brown 1991, Rosenberg et al. 1991, Busch and Smith 1993).

Disturbance regimes imposed by man (e.g., grazing, water diversion,

flood control, woodcutting, and vegetation clearing) have facilitated

the spread of tamarisk (Behle and Higgins 1959, Kerpez and Smith 1987,

Hunter et al. 1988, Rosenberg et al. 1991). Cattle find tamarisk

unpalatable. However, they eat the shoots and seedlings of cottonwood

and willow, acting as a selective agent to shift the relative abundance

of these species (Kerpez and Smith 1987). Degradation and, in some

cases, loss of native riparian vegetation lowered the water table and

resulted in the loss of perennial flows in some streams. With its deep

root system and adaptive reproductive strategy, tamarisk thrives or

persists where surface flow has been reduced or lost. Further, tamarisk

establishment often results in a self-perpetuating regime of periodic

fires, which were uncommon in native riparian woodlands (Busch and

Smith 1993).

Manipulation of perennial rivers and streams has resulted in

habitats that tend to allow tamarisk to outcompete native vegetation.

Construction of dams created impoundments that destroyed native

riparian communities. Dams also eliminated or changed flood regimes,

which were essential in maintaining native riparian ecosystems.

Changing (usually eliminating) flood regimes provided a competitive

edge to tamarisk. In contrast to native phreatophytes, tamarisk does

not need floods and is intolerant of submersion when young. Diversion

of water caused the lowering of near-surface groundwater and reduced

the relative success of native species in becoming established.

Irrigation water containing high levels of dissolved salts also favors

tamarisk, which is more tolerant of high salt levels than most native

species (Kerpez and Smith 1987, Busch and Smith 1993).

The rapid spread of tamarisk has coincided with the decline of the

southwestern willow flycatcher. Although E. t. extimus has been

documented nesting in tamarisk, it is not known whether, over the long

term, reproductive success of southwestern willow flycatchers nesting

in tamarisk has differed from the success of flycatchers nesting in

native vegetation. Studies in Arizona have documented low breeding

densities and low reproductive success for southwestern willow

flycatchers nesting in tamarisk (Hunter et al. 1988, Muiznieks et al.

1994). These data, coupled with a possible decrease in the arthropod

prey base and thermal protection for nests provided by tamarisk,

suggest that tamarisk may provide poor quality nesting habitat.

However, more extensive comparative studies are needed to determine the

overall impact on the southwestern willow flycatcher of the conversion

of native broadleaf-dominated riparian habitat to tamarisk-dominated

habitat.

Other studies of riparian bird communities have documented changes

in bird species diversity, corresponding with invasion by tamarisk.

Conversion to tamarisk typically coincides with reduction or

complete loss of bird species strongly associated with cottonwood-

willow habitats. These include the yellow-billed cuckoo (Coccyzus

americanus), summer tanager (Piranga rubra), northern oriole (Icterus

galbula), and the southwestern willow flycatcher (Hunter et al. 1987,

Hunter et al. 1988, Rosenberg et al. 1991). While Brown and Trosset

(1989) believed tamarisk may serve as an ``ecological equivalent'' to

native vegetation, they noted that their study occurred where a

tamarisk community became established where no native equivalent

existed before.

Some authors believe tamarisk may not provide the thermal

protection that native broadleaf species do (Hunter et al. 1987, Hunter

et al. 1988). This could be important at lower elevations in the

Southwest, where extreme high temperatures are common during the bird's

midsummer breeding season. It is [[Page 10709]] also possible that

tamarisk affects E. t. extimus by altering the riparian insect fauna

(Carothers and Brown 1991). Some sources also speculated that nests in

tamarisk stands may be more easily located by brown-headed cowbirds

(see cowbird discussion below). Hunter et al. (1987) reported the

willow flycatcher as one of seven midsummer-breeding builders of open

nests that were found in tamarisk at higher elevations but not lower

elevations. Nesting E. t. extimus have been found in tamarisk at middle

elevations (610-1200 m (2000-3500 feet)) (Hundertmark 1978, Hubbard

1987, Hunter et al. 1987, Brown 1988, Sogge et al. 1993, Muiznieks et

al. 1994). However, nest success in tamarisk at these elevations

appears to be low (Sogge and Tibbitts 1992, Sogge et al. 1993,

Muiznieks et al. 1994). The species is essentially absent from

tamarisk-dominated habitats below 610 m (2000 feet). On the lower

Colorado River (approximately 25 m (80 feet)) where tamarisk is widely

dominant, the only territories found in recent decades were in relict

stands dominated by willow, cottonwood, and other native vegetation

(Muiznieks et al. 1994). Unitt (1987) speculated that at higher

elevations and in the eastern portion of its range, some E. t. extimus

populations may be adapting to tamarisk.

Water developments also likely reduced and modified southwestern

willow flycatcher habitat. The series of dams along most major

southwestern rivers (Colorado, Gila, Salt, Verde, Rio Grande, Kern, San

Diegito, and Mojave) have altered riparian habitats downstream of dams

through hydrological changes, vegetational changes, and inundated

habitats upstream. New habitat is sometimes created along the shoreline

of reservoirs, but this habitat (often tamarisk) is often unstable

because of fluctuating levels of regulated reservoirs (Grinnell 1914,

Phillips et al. 1964, Rosenberg et al. 1991). Construction of Glen

Canyon Dam on the Colorado River allowed establishment of a tamarisk

riparian community downstream in the Grand Canyon, where a small

population of E. t. extimus exists, with poor reproduction (Brown 1991,

Sogge et al. 1993). However, Lake Powell, formed upstream of the dam,

inundated what was apparently superior habitat, with E. t. extimus

considered common (Behle and Higgins 1959).

Diversion and channelization of natural watercourses are also

likely to have reduced E. t. extimus habitat. Diversion results in

diminished surface flows and increased salinity of residual flows.

Consequent reductions and composition changes in riparian vegetation

are likely. Channelization often alters stream banks and fluvial

dynamics necessary to maintain native riparian vegetation.

Suckling et al. (1992) suggested that logging in the upper

watersheds of southwestern rivers may constitute another potential

threat to the southwestern willow flycatcher. They stated that logging

increases the likelihood of damaging floods in southwestern willow

flycatcher nesting habitat.

Finally, the willow flycatcher (all subspecies) is listed among

neotropical migratory birds that may be impacted by alteration of

wintering habitat, as through tropical deforestation (Finch 1991,

Sherry and Holmes 1993).

Population Trends for Each State Are Discussed Briefly Below

California. All three resident subspecies of the willow flycatcher

(E. t. extimus, E. t. brewsteri, and E. t. adastus) were once

considered widely distributed and common in California, wherever

suitable habitat existed (Wheelock 1912, Willett 1912, Grinnell and

Miller 1944). The historic range of E. t. extimus in California

apparently included all lowland riparian areas of the southern third of

the State. Unitt (1984, 1987) concluded that it was once fairly common

in the Los Angeles basin, the San Bernardino/Riverside area, and San

Diego County. Willett (1912, 1933) considered the bird to be a common

breeder in coastal southern California. Nest and egg collections

indicate the bird was a common breeder along the lower Colorado River

near Yuma in 1902 (T. Huels, University of Arizona in litt.,

transcripts of H. Brown's field notes).

All three willow flycatcher subspecies breeding in California have

declined, with declines most critical in E. t. extimus, which remains

only in small, disjunct nesting groups (Unitt 1984 and 1987, Gaines

1988, Schlorff 1990, Service unpubl. data). Only two nesting groups

have been stable or increasing in recent years. One is on private land

where habitat impacts from livestock grazing have been virtually

eliminated (Harris et al. 1987, Whitfield 1990). This group on the

South Fork of the Kern River experienced numerical declines in 1991 and

1992, but increases in nesting success were realized in 1992 and 1993,

attributed to shaking (killing) or removing cowbird eggs or nestlings

found in flycatcher nests, and trapping cowbirds (Whitfield and Laymon,

Kern River Research Center, in litt. 1993). The other apparently stable

nesting group is along the Santa Margarita River on Marine Corps Base

Camp Pendleton, where cowbird numbers have also been reduced by

trapping (Griffith and Griffith 1993). Approximately eight other

nesting groups are known in southern California, all of which consisted

of six or fewer nesting pairs in recent years (Unitt 1987, Schlorff

1990, Service, unpubl. data). Using the most recent information for all

areas, approximately 70 pairs and 8 single southwestern willow

flycatchers are known to exist in California. Where information on

population trends since the mid-1980's is available, most areas show

declines. Three recent status reviews considered extirpation from

California to be possible, even likely, in the foreseeable future

(Garrett and Dunn 1981, Harris et al. 1986, Schlorff 1990). The State

of California classifies the willow flycatcher as endangered

[California Department of Fish and Game (CDFG) 1992].

Arizona. Records indicate that the former range of the southwestern

willow flycatcher in Arizona included portions of all major watersheds

(Colorado, Salt, Verde, Gila, Santa Cruz, and San Pedro). Historical

records exist from the Colorado River near Lee's Ferry and near the

Little Colorado River confluence (Phillips, pers. comm., cited in Unitt

1987), and along the Arizona-California border (Phillips 1948, Unitt

1987), the Santa Cruz River near Tucson (Swarth 1914, Phillips 1948),

the Verde River at Camp Verde (Phillips 1948), the Gila River at Fort

Thomas (W.C. Hunter, pers. comm., cited in Unitt 1987), the White River

at Whiteriver, the upper and lower San Pedro River (Willard 1912,

Phillips 1948), and the Little Colorado River headwaters area (Phillips

1948).

The southwestern willow flycatcher has declined throughout Arizona.

The subspecies was apparently abundant on the lower Colorado River in

1902 (T. Huels in litt., transcripts of H. Brown's field notes), but

only four to five territories were located in 1993 (Muiznieks et al.

1994). Elsewhere in the State, E. t. extimus persists only in several

small, widely scattered locations. In the Grand Canyon, several groups

of nesting birds have fluctuated from a high of 11 singing males in

1986 (Brown 1988) to two pairs and three single birds in 1992 (Sogge

and Tibbitts 1992). Grand Canyon surveys in 1993 located 13 birds; six

unpaired individuals, two pairs, and what appeared to be one male with

two females. No nesting attempts were successful (Sogge et al. 1993).

Although Brown (et al. 1987) noted E. t. extimus as nesting in Havasu

Canyon, in 1993 none were located there and cowbirds were abundant

(Sogge et al. 1993). A [[Page 10710]] location on the lower San Pedro

River apparently supported relatively large numbers of E. t. extimus in

the 1940's (G. Monson, private individual, in litt. 1993 and pers.

comm. 1993), but only a single pair in 1978 and 1979, and none in 1986

(Unitt 1987). Following habitat improvements at this locale, six to

seven singing males were present in 1993, and a total of 11 singing

males were located at two other locations on the lower San Pedro in

1993 (Muiznieks et al. 1994).

Historically occupied habitat on the upper San Pedro River is in

the process of rehabilitation, but remains unoccupied by nesting E. t.

extimus (Krueper and Corman 1988, D. Krueper unpubl. data). Two small

groups at high elevations in the White Mountains, comprising

approximately five singing males each, have remained relatively stable

numerically from 1985 to 1993 (Muiznieks et al. 1994, Arizona Game and

Fish Department (AGFD), unpubl. data). At a site on the Verde River in

central Arizona where R. Ohmart (unpubl. data) observed four nesting

pairs in 1992, one pair and one single male were present in 1993. The

single nest produced only a cowbird young. Of 13 river reaches in

Arizona studied by Hunter et al. (1987), nesting E. t. extimus were

extirpated from eight, declining in two, and present in stable numbers

in three.

Statewide surveys in 1993 located between 42 and 56 territorial

males, and all nest sites were considered vulnerable to habitat loss

and cowbird parasitism (Muiznieks et al. 1994). Preliminary data from

1994 surveys indicate that approximately 70 to 80 breeding pairs were

found at a total of 12 locations in the State. This included the

discovery of a group of flycatchers at one location consisting of

approximately 15 breeding pairs. Brood parasitism by cowbirds was

documented at at least six (50%) of those 12 sites. Brown-headed

cowbirds were documented at all 12 breeding locations (Arizona Game and

Fish Department, in prep.).

Where information on population trends since the mid-1980's is

available, most areas show declines and/or high rates of cowbird

parasitism. In early 1993, catastrophic flooding on the Verde, Gila,

and San Pedro Rivers temporarily damaged many sites inhabited since the

mid-1980's, and much potential habitat. Unitt (1987) concluded that

``Probably the steepest decline in the population levels of E. t.

extimus has occurred in Arizona * * * E. t. extimus has been extirpated

from much of the area from which it was originally described, the

riparian woodlands of southern Arizona.'' The State of Arizona

classifies the willow flycatcher as endangered (AGFD 1988).

New Mexico. Bailey (1928) classified breeding willow flycatchers in

New Mexico as E. t. brewsteri, according to Oberholser's (1918)

taxonomy of that time. Because of few records at that time, she

believed that either the bird was rare or was overlooked by most

observers and collectors. More recently, Hubbard (1987) reviewed and

summarized the flycatcher's status in New Mexico. He classified

breeding birds in the State as E. t. extimus and reported breeding

locations that were generally confined to the regions west of the Rio

Grande, with records from the Rio Grande, Chama, Zuni, San Francisco,

and Gila drainages (See also Hubbard 1982). However, he provisionally

assigned all willow flycatchers nesting in New Mexico to E. t. extimus,

noting records from the Pecos River and Penasco Creek in the southeast

and from near Las Vegas in the northeast.

Both Hubbard (1987) and Unitt (1987) believed that the overall

range of E. t. extimus had not been reduced in New Mexico, but that

habitat and numbers had declined. Unitt (1987) believed the majority of

all remaining nesting birds may occur in New Mexico. Areas with 19 and

53 singing flycatchers, not distinguished as nesting or migrants, were

found on the upper Gila River (Montgomery et al. 1985, cited in

Suckling et al. 1992). Preliminary data from 1994 surveys indicate that

this breeding group is still present. However, the breeding status of

flycatchers and trend over time have not been determined (S.O.

Williams, New Mexico Department of Game and Fish--pers. comm.)

Hubbard (1987) noted that data were lacking for trends of most

nesting areas. However, where data were available, they indicated loss

of a group of 15 breeding pairs by the rising waters of Elephant Butte

Reservoir. The willow flycatcher was considered fairly common in this

area on the middle Rio Grande in the late 1970's (Hundertmark 1978).

Hubbard hypothesized that some of these birds could have moved

upstream, to new shoreline habitat created by the impoundment. Between

1987 and 1990, bird surveys along the Rio Grande Valley State Park in

Albuquerque found a single singing willow flycatcher during the

breeding season (Hoffman 1990). Current trends in New Mexico are not

being extensively monitored. However, in 1992, 71 transects along the

Rio Grande were surveyed for breeding birds, but not specifically

targeting willow flycatcher habitat. A single willow flycatcher was

located near Espanola (Leal, Meyer and Thompson, unpubl. data). In

1993, surveys of 52 locations found 31 pairs or singing males at 15 of

those locations (S.O. Williams III, New Mexico Department of Game and

Fish (NMDGF), in litt. 1993). Hubbard (1987) estimated that the State

population may total 100 pairs; that estimate has not been revised.

Hubbard (1987) found that ``the conclusion is virtually inescapable * *

* a decrease has occurred in the population of breeding willow

flycatchers in New Mexico over historic time,'' resulting from habitat

loss. The State of New Mexico classifies the willow flycatcher as

endangered (NMDGF 1988).

Texas. The eastern limit of the southwestern willow flycatcher's

breeding range is in western Texas (Unitt 1987). Collections have been

made at Fort Hancock on the Rio Grande (Phillips 1948), in the

Guadalupe Mountains (Phillips, pers. comm., cited in Unitt 1987), the

Davis Mountains (Oberholser 1974), and from unspecified locales in

Brewster County (Wolfe 1956). Wauer (1973 and 1985) considered E. t.

extimus a rare summer resident in Big Bend National Park. Data are

lacking on current population levels and trends in Texas. Loss and

modification of habitat may have reduced populations on the Rio Grande

and Pecos Rivers.

Utah. The north-central limit of breeding southwestern willow

flycatchers is in southern Utah. Behle (1985) and Unitt (1987) believed

a clinal gradation between E. t. extimus and E. t. adastus existed, but

Browning (1993) disagreed, identifying a range boundary at

approximately the 38th north parallel. Southern Utah is characterized

by extreme topographic relief. In this region, subspecific separation

may be a function of elevation, with E. t. extimus at lower elevations

(e.g., Virgin and Colorado Rivers) and E. t. adastus higher (e.g.,

Sevier River, wet meadows of mountains and high plateaus). Records that

are likely to represent E. t. extimus are from the Virgin River

(Phillips 1948, Wauer and Carter 1965, Whitmore 1975), Kanab Creek, and

along the San Juan and Colorado Rivers (Behle et al. 1958, cited in

Unitt 1987; Behle and Higgins 1959, Behle 1985; see also Browning

1993). Other reports document the subspecies being present along the

Virgin, Colorado, San Juan, and perhaps Paria Rivers (BLM, unpubl.

data). Although Behle believed E. t. extimus was always rare in

southern Utah overall (pers. comm. cited in Unitt 1987), he considered

it a locally common breeding resident where habitat existed along the

Colorado River [[Page 10711]] and its tributaries in southeastern Utah

(Behle and Higgins 1959).

Few data are available on population trends in southern Utah.

However, loss and modification of habitat is likely to have reduced

populations on the Virgin, Colorado, and San Juan Rivers. These losses

have been due to suburban expansion and habitat changes along the

Virgin River, inundation by Lake Powell on the Colorado and San Juan

Rivers, and encroachment of tamarisk throughout the region (Unitt 1987,

BLM unpublished data).

Nevada. Unitt (1987) reported only three records for Nevada, all

made before 1962. Unitt (1987), Hubbard (1987), and Browning (1993) all

considered southern Nevada (approximately south of 38 deg. north

parallel) to be within the range of E. t. extimus. However, no recent

data are available on population levels or trends. Habitat may remain

along the lower Virgin River and at the inflow of the Virgin River into

Lake Mead. However, loss and modification of habitat is likely to have

reduced populations on the Virgin and Colorado Rivers.

Colorado. Whether or not the southwestern willow flycatcher breeds

in Colorado is unclear. Hubbard (1987) believed the subspecies ranged

into extreme southwestern Colorado, Browning (1993) was noncommittal,

and Unitt (1987) tentatively used the New Mexico-Colorado border as the

boundary between E. t. extimus and E. t. adastus. Several specimens

taken in late summer have been identified as E. t. extimus, but nesting

was not confirmed (Bailey and Niedrach 1965). Phillips (1948) cautioned

that willow flycatchers in this region displayed considerable

individual variation and may represent intergrades between E. t.

extimus and E. t. adastus. No recent data are available on occurrence,

population levels, or trends in this area.

Mexico. Six specimens from Baja California del Norte and two from

Sonora were discussed by Unitt (1987). He and Phillips (pers. comm.,

cited in Unitt 1987) believed E. t. extimus was not common in

northwestern Mexico. Wilbur (1987) was skeptical of its presence as a

breeder in Baja California. In the more general treatments of field

guides, the willow flycatcher is described as breeding in extreme

northwestern Mexico, including northern Baja California del Norte

(Blake 1953, Peterson 1973). No recent data are available on current

population levels or trends.

Using the most recent censuses and estimates for all areas, the

estimated total of all southwestern willow flycatchers is approximately

300 to 500 nesting pairs. Unitt (1987) believed the total was ``well

under'' 1000 pairs, more likely 500. The regional estimates and

information on which these total estimates are based generally date

from the late 1980's to 1993 (e.g., Hubbard 1987, T. Johnson 1989).

Virtually all nesting groups monitored since that time have continued

to decline (Whitfield 1990, Brown 1991, Sogge et al. 1993, Whitfield

and Laymon, unpubl. data).

B. Overutilization for Commercial, Recreational, Scientific, or

Educational Purposes

The Service is unaware of threats resulting from overutilization.

C. Disease or Predation

The Service is unaware of any disease that constitutes a

significant threat to E. t. extimus. Boland et al. (1989) found only

one case of larval parasites in willow flycatcher nestlings in

California.

Predation of southwestern willow flycatchers may constitute a

significant threat and may be increasing with habitat fragmentation.

Where E. t. extimus has been extirpated in the lower Colorado River

valley, Rosenberg et al. (1991) found increases in the great-tailed

grackle (Quiscalus mexicanus), which preys on the eggs and young of

other birds (Bent 1965). Whitfield (1990) found predation on E. t.

extimus nests to be significant. Predation increased with decreasing

distance from nests to thicket edges, suggesting that habitat

fragmentation may increase the threat of predation.

D. The Inadequacy of Existing Regulatory Mechanisms

The Migratory Bird Treaty Act (MBTA)(16 U.S.C. Sec. 703-712) is the

only current Federal protection provided for the southwestern willow

flycatcher. The MBTA prohibits ``take'' of any migratory bird, which is

defined as: ``* * * to pursue, hunt, shoot, wound, kill, trap, capture,

or collect, or attempt to pursue, hunt, shoot, wound, kill, trap,

capture, or collect * * *'' However, unlike the Act, there are no

provisions in the MBTA preventing habitat destruction unless direct

mortality or destruction of active nests occurs.

The majority of the southwestern willow flycatcher's range lies

within California, Arizona, and New Mexico (Phillips 1948, Hubbard

1987, Unitt 1987). All of those States classify the willow flycatcher

as endangered (AGFD 1988, NMDGF 1988, CDFG 1992). The State listings in

New Mexico and Arizona do not convey habitat protection or protection

of individuals beyond existing regulations on capture, handling,

transportation, and take of native wildlife. The California Endangered

Species Act (CESA) prohibits unpermitted possession, purchase, sale, or

take of listed species. However, the CESA definition of take does not

include harm, which under the Act can include destruction of habitat

that actually kills or injures wildlife by significantly impairing

essential behavioral patterns (50 CFR 17.3). However, CESA requires

consultation between the CDFG and other State agencies to ensure that

activities of State agencies will not jeopardize the continued

existence of State-listed species (E. Toffoli, State of California, in

litt. 1992). The Service believes that this and other regulatory

mechanisms are inadequate to ensure the continued existence of the

southwestern willow flycatcher.

E. Other Natural or Manmade Factors Affecting Its Continued Existence

The riparian habitat of the southwestern willow flycatcher has

always been rare and has become more so. Its habitat rarity and small,

isolated populations make the remaining E. t. extimus increasingly

susceptible to local extirpation through stochastic events such as

floods, fire, brood parasitism, predation, depredation, and land

development. In early 1993, catastrophic floods in southern California

and Arizona impacted much of the remaining occupied or potential

breeding habitat. Historically, these floods have always destroyed

habitat but were also important events in regenerating cottonwood-

willow communities. However, with little southwestern willow flycatcher

habitat remaining, widespread events like those of 1993 could destroy

virtually all remaining habitat throughout all or a significant portion

of the subspecies' range. Further, regeneration with natural vegetation

after floods may be inhibited if the area is subjected to overgrazing

by domestic livestock.

The disjunct nature of habitats and small breeding populations

impede the flow of genetic material and reduce the chance of

demographic rescue from migration from adjacent populations. The

resulting constraints on the gene pool intensify the external threats

to the species.

Brood parasitism by the brown-headed cowbird also threatens the

southwestern willow flycatcher. Cowbirds lay their eggs in the nests of

other, usually smaller, songbirds. The cowbird often removes a number

of the host's eggs and replaces them with an equal number of cowbird

eggs. The host [[Page 10712]] species then incubates the cowbird eggs,

which typically hatch prior to the host's own eggs. Cowbird eggs

require a relatively short incubation period of 10 to 12 days. Thus,

the young cowbirds have several advantages over the host's young; they

hatch earlier, they are larger, and they are also more aggressive than

the host's young. Cowbird nestlings typically outcompete those of the

host species for parental care, and, as a result, the host species' own

reproduction is reduced or eliminated (Bent 1965, McGeen 1972, Mayfield

1977a, Harrison 1979, Brittingham and Temple 1983).

The brown-headed cowbird commonly preys on insects stirred up by

grazing ungulates, and was originally restricted to the Great Plains,

where it was strongly associated with American bison (Bison bison). As

North America was settled, cowbirds became associated with livestock

and human agriculture because of the food sources they provided (Bent

1965, Flett and Sanders 1987, Valentine et al. 1988). The expansion of

agriculture, livestock grazing, and wide scale human activities in

general caused opening and fragmenting of forest and woodland habitats.

Habitat fragmentation and agriculture are strongly correlated with

increased rates of brood parasitism by brown-headed cowbirds (Rothstein

et al. 1980, Brittingham and Temple 1983, Airola 1986, Robinson et al.

1993). Some species are likely to have adapted to parasitism over time,

particularly prairie nesters in the original range of the cowbird.

However, the cowbird's rapid expansion now brings it into contact with

forest and woodland species not adapted to deal with brood parasitism,

significantly impacting those species (Hill 1976, Mayfield 1977a,

Robinson et al. 1993).

The brown-headed cowbird was apparently an uncommon bird within the

range of E. t. extimus, until the late 1800's. Since then, the species

has greatly expanded in numbers and distribution throughout the region

(Laymon 1987, Rothstein in prep.). Increases in cowbirds in the San

Bernardino Valley between 1918 and 1928 caused Hanna (1928)

``considerable alarm.'' Although Friedmann et al. (1977) reported

relatively low rates of parasitism of willow flycatchers in the western

United States, this was apparently owing to their data (egg sets) being

collected prior to the major incursions of cowbirds into Pacific coast

riparian habitats (L. Kiff, Western Foundation for Vertebrate Zoology,

in litt. 1993). Brood parasitism of several subspecies of the willow

flycatcher, including E. t. extimus, by brown-headed cowbirds is well

documented (Hanna 1928, Rowley 1930, Willett 1933, Hicks 1934, King

1954, Holcomb 1972, Friedmann et al. 1977, Garret and Dunn 1981, Harris

et al. 1987, Brown 1988, 1991, Sedgewick and Knopf 1988, Whitfield

1990, Harris 1991, Sogge et al. 1993, Muiznieks et al. 1994).

The increases in cowbirds in the Southwest and parasitism of E. t.

extimus and other birds are generally attributed to the following

scenario: The introduction of modern human settlements, livestock

grazing, and other agricultural developments resulted in habitat

fragmentation. Simultaneously, livestock grazing and other agricultural

developments served as vectors for cowbirds by providing feeding areas

near host species' nesting habitats (Hanna 1928, Gaines 1974, Mayfield

1977a). Cowbirds may travel almost 7 kilometers (4.2 miles) from

feeding sites where livestock congregate to areas where host species

are parasitized (Rothstein et al. 1984). These factors increased both

the vulnerability of E. t. extimus and the likelihood of encounters

with cowbirds. Finally, the high edge-to-interior ratio of linear

riparian habitats like those used by E. t. extimus renders birds

nesting there particularly vulnerable to parasitism (Airola 1986,

Laymon 1987, Harris 1991). Linear riparian habitats are also especially

vulnerable to fragmentation by grazing, which further increases both

the edge-to-interior ratio and the threat of parasitism.

The effects of parasitism by brown-headed cowbirds on willow

flycatchers include reducing nest success rate and egg-to-fledging

rate, and delaying successful fledging (because of renesting attempts)

(Harris 1991). A common response to parasitism is abandonment of the

nest (Holcomb 1972). Willow flycatchers may also respond to parasitism

by ejecting cowbird eggs, by burying them with nesting material and

renesting on top of them, or by renesting in another nest (Harris et

al. 1991). However, the success rate of renesting is often reduced,

because these attempts produce fledglings several weeks later than

normal, which may not allow them adequate time to prepare for migration

(Harris 1991). Renesting also usually consists of smaller clutches,

further reducing overall reproductive potential (Holcomb 1974).

McCabe (1991) downplayed the significance of cowbird parasitism as

a threat to any species except Kirtland's warbler (Dendroica

kirtlandii). McCabe's monograph focussed on the combined ``Traill's

flycatcher'' superspecies, comprised of E. t. traillii and E. alnorum

in marshy habitats in the upper Midwest, where parasitism rates ranged

from 3 percent to 19 percent. However, perhaps reflecting his regional

perspective, he characterized the high parasitism rates on willow

flycatchers reported by Trautman (1940, cited in McCabe 1991) and

Sedgwick and Knopf (1988) as aberrant (56 percent and 41 percent,

respectively). McCabe considered the high rates the result of the ``* *

* linear configuration of the habitat * * * [c]owbirds lay eggs in

songbird nests closest to cover edge.'' The vast majority of

southwestern willow flycatcher habitat is very linear and may

experience higher rates of parasitism than other willow flycatcher

subspecies.

Brittingham and Temple (1983) considered ``high'' parasitism rates

(percent of nests parasitized) to be 24 percent, with some as high as

72 percent. Mayfield (1977a) thought a species (or population) might be

able to survive a 24 percent parasitism rate, but that losses much

higher than that ``would be alarming.'' Parasitism rates of 72 percent

to 83 percent on Kirtland's warbler (Mayfield 1977b) resulted in a

precipitous population decline. Where parasitism rates are known for E.

t. extimus, they are comparable to rates for Kirtland's warbler and are

capable of causing similar declines. In California, parasitism rates

ranged from 50 percent to 80 percent between 1987 and 1992, when an

estimated population size decreased from 44 to 28 nesting pairs

(Whitfield 1990, Harris et al. 1991, Whitfield and Laymon, unpubl.

data). These parasitism rates were considered minimum measures, because

several nests were abandoned each year due to unknown causes, which

could have been parasitism. Brown (1988) reported an average 50 percent

parasitism rate in the Grand Canyon between 1982 and 1987. Although his

estimated population increased from two pairs to 11 during that period,

it has since decreased back as low as two nesting pairs (Brown 1991,

Sogge and Tibbitts 1992). In 1993, parasitism reached 100 percent in

the Grand Canyon, and no E. t. extimus were fledged (Sogge et al.

1993). Harris et al. (1991) believed that the parasitism rates observed

on the Kern River in 1987 (68 percent of all nests, 88 percent of all

nest territories) were high enough to prevent E. t. extimus from

recolonizing lowland riparian habitat, even if it were restored.

Rothstein et al. (1980), Stafford and Valentine (1985), and Harris

(1991) believed parasitism may be correlated with elevation, being more

severe at lower elevations. Coupled with greater loss of lowland

(desert) riparian habitat, [[Page 10713]] the effects of habitat loss

and parasitism are compounded. However, cowbirds now appear to be

increasing at higher elevations (Hanka 1985).

In addition to causing habitat degradation and facilitating brood

parasitism, livestock grazing in and near riparian areas may also

threaten E. t. extimus through direct mortality. Livestock in riparian

habitats sometimes make physical contact with nests or supporting

branches, resulting in destruction of nests and spillage of eggs or

nestlings. All known documentation of this threat involves E. t.

brewsteri, perhaps because virtually all known remaining populations of

E. t. extimus are in ungrazed habitats (Serena 1982, Harris et al.

1987, Whitfield and Laymon, unpubl. data). Valentine et al. (1988)

studied willow flycatchers in California from 1983 through 1987, when

11 of their 20 recorded nesting attempts failed. They found that

``Prior to reduction of grazing intensity in 1987, livestock accounted

for 36 percent of the failed nests or 20 percent of all nesting

attempts. In addition, livestock destroyed four successful nests

shortly after the young had fledged.'' Stafford and Valentine (1985)

reported that three of eight (37.5 percent) willow flycatcher nests in

their study site were probably destroyed by cattle. Flett and Sanders

(1987) documented no nest upsets due to livestock but noted the

vulnerability of nests to upset, due to their placement low in willow

clumps (see also Serena 1982). Livestock grazing may affect E. t.

extimus similarly.

The southwestern willow flycatcher's preference for, and former

abundance in, floodplain areas that are now largely agricultural may

indicate a potential threat from pesticides. Where flycatcher

populations remain, they are sometimes in proximity to agricultural

areas, with the associated pesticides and herbicides. Without

appropriate precautions, these agents may potentially affect the

southwestern willow flycatcher through direct toxicity or effects on

their insect food base. No quantitative data on this potential threat

are known at this time.

Recreation that is focused on riparian areas, particularly during

warm summer breeding months, may also constitute a threat to E. t.

extimus. Taylor (1986) found a possible correlation between

recreational activities and decreased riparian bird abundance.

Blakesley and Reese (1988) reported the willow flycatcher (probably E.

t. adastus) as one of seven species negatively associated with

campgrounds in riparian areas in northern Utah. It is unknown whether

these possible effects involve impacts to habitat or disturbance of

nesting birds.

The Service has carefully assessed the best scientific and

commercial information available regarding the past, present, and

future threats faced by this species in determining to make this rule

final. Based on this evaluation, the preferred action is to list the

southwestern willow flycatcher as endangered. A decision regarding

designation of critical habitat for this species is being deferred, and

a final decision regarding the designation will be made by July 23,

1995. Critical habitat for this species is not now determinable.

Critical Habitat

Critical Habitat is defined in section 3 of the Act as (i) the

specific areas within the area occupied by a species, at the time it is

listed in accordance with the Act, on which are found those physical or

biological features (I) essential to the conservation of the species

and (II) that may require special management considerations or

protection and; (ii) specific areas outside the geographical area

occupied by a species at the time it is listed, upon a determination

that such areas are essential for the conservation of the species.

``Conservation'' means the use of all methods and procedures needed to

bring the species to a point at which listing under the Act is no

longer necessary.

Section 4(a)(3) of the Act and implementing regulations (50 CFR

424.12) require that, to the maximum extent prudent and determinable,

the Secretary designate critical habitat at the time a species is

determined to be endangered or threatened. Critical habitat was

proposed to be designated for the flycatcher at the time it was

proposed for listing as endangered to encompass approximately 640 miles

(1000 km) of riparian zones in the States of California, Arizona, and

New Mexico.

After reviewing comments submitted during the public comment period

the Service is deferring the designation of critical habitat for this

endangered species. The Service received numerous comments on the

proposed rule, including many recommendations for additions and

deletions to proposed critical habitat. The Service is reviewing these

comments as well as survey data collected in 1994. These sources

included more complete information on the primary constituent elements

of flycatcher habitat and on the distribution of that habitat across

the bird's range. Substantial disagreement has also been found among

scientists knowledgeable about the species regarding the proposed

designations. Further, written comments submitted by State agencies

recommended substantial changes in proposed critical habitat areas.

The Service is presently reconsidering the prudence of critical

habitat designation for this species, the need for special management

considerations or protection of habitat within the species' range, and

the proper boundaries of any areas that might be designated as critical

habitat. Issues raised in public comments, new information, and the

lack of the economic information necessary to perform the required

economic analysis cause the Service to conclude that critical habitat

is not now determinable and to invoke an extension until July 23, 1995,

pursuant to 16 U.S.C. Sec. 1533(b)(6)(C) for reaching a final decision

on the proposal of critical habitat for the flycatcher. The Service has

determined that this is in compliance with provisions of 50 CFR

424.12(a) and Sec. 424.17, regarding delaying final rules on proposed

critical habitat designations, and with provisions for addressing State

agencies that disagree in whole or part with a proposed rule (50 CFR

424.18(c)). In order to assist in its deliberation, the Service is

reopening comment on the proposal to designate critical habitat for a

period of 60 days. Comments are particularly sought on the following

topics:

1. The need for special management of areas within the range of the

flycatcher, including those proposed as critical habitat as well as

other areas,

2. The net benefit to the flycatcher in addition to the protection

provided by its listing as endangered likely to accrue from a

designation of critical habitat, and

3. Any indication that areas should be added to or excluded from

those proposed for designation.

Comments already received that address the above topics will be

considered in reaching a final decision regarding critical habitat

designation, and need not be resubmitted.

Available Conservation Measures

Conservation measures provided to species listed as endangered or

threatened under the Act include recognition, recovery actions,

requirements for Federal protection, and prohibitions against certain

practices. Recognition through listing encourages and results in

conservation actions by Federal, State, and local agencies, private

organizations, and individuals. The Act provides for possible land

acquisition and cooperation with the States and requires that recovery

actions be carried out for all listed species. The protection required

of Federal agencies [[Page 10714]] and the prohibitions against taking

and harm are discussed, in part, below.

Section 7(a) of the Act, as amended, requires Federal agencies to

evaluate their actions with respect to any species that is proposed or

listed as endangered or threatened and with respect to its critical

habitat, if any is being designated. Regulations implementing this

interagency cooperation provision of the Act are codified at 50 CFR

Part 402. Section 7(a)(4) requires Federal agencies to confer

informally with the Service on any action that is likely to jeopardize

the continued existence of a proposed species or result in destruction

or adverse modification of proposed critical habitat. If a species is

listed subsequently, Section 7(a)(2) requires Federal agencies to

ensure that activities they authorize, fund, or carry out are not

likely to jeopardize the continued existence of such a species or

destroy or adversely modify its critical habitat. If a Federal action

may affect a listed species or its critical habitat, the responsible

Federal agency must enter into consultation with the Service.

No conservation plans or habitat restoration projects specific to

the southwestern willow flycatcher exist on lands managed by the U.S.

Forest Service (USFS), BLM, U.S. Bureau of Reclamation (Reclamation),

Indian Nations, State agencies, or the Service. The USFS and BLM have

focussed some attention on modifying livestock grazing practices in

recent years, particularly as they affect riparian ecosystems. As

mitigation for other projects impacting riparian habitats, Reclamation

is engaged in riparian habitat restoration projects in several areas in

the range of E. t. extimus, including some historical nesting

locations. The BLM currently manages approximately 40 miles of the

upper San Pedro River in Arizona (including historic nest sites), as a

Riparian National Conservation Area. Riparian habitat rehabilitation is

also underway at several National Wildlife Refuges in the breeding

range of E. t. extimus, which are managed by the Service. The Nature

Conservancy manages one of the largest remaining flycatcher

populations, as well as several other areas with high recovery

potential. The U.S. Marines have maintained a cowbird control program

near the Santa Margarita River to benefit the least Bell's vireo. This

program has benefitted nesting southwestern willow flycatchers there.

Grand Canyon National Park has instituted a seasonal recreation closure

at the remaining site with nesting willow flycatchers in the Grand

Canyon, and has begun a cowbird monitoring program.

The Act and implementing regulations found at 50 CFR 17.21 set

forth a series of general prohibitions and exceptions that apply to all

endangered wildlife. These prohibitions, in part, make it illegal for

any person subject to the jurisdiction of the United States to take

(includes harass, harm, pursue, hunt, shoot, wound, kill, trap, or

collect; or to attempt any of these), import or export, ship in

interstate commerce in the course of commercial activity, or sell or

offer for sale in interstate or foreign commerce any listed species. It

also is illegal to possess, sell, deliver, carry, transport, or ship

any such wildlife that has been taken illegally. Certain exceptions

apply to agents of the Service and State conservation agencies.

Permits may be issued to carry out otherwise prohibited activities

involving endangered wildlife species under certain circumstances.

Regulations governing permits are at 50 CFR 17.22 and 17.23. Such

permits are available for scientific purposes, to enhance the

propagation or survival of the species, and/or for incidental take in

connection with otherwise lawful activities.

It is the policy of the Service (59 FR 34272) to identify to the

maximum extent practicable at the time a species is listed those

activities that would or would not constitute a violation of section 9

of the Act. The intent of this policy is to increase public awareness

of the effect of a listing on proposed and ongoing activities within a

species' range. The Service believes that, based on the best available

information, the following are examples of actions that will not result

in a violation of section 9:

(1) Dispersed recreational activities near willow flycatcher

breeding areas that do not disrupt normal flycatcher breeding

activities and behavior, attract avian and mammalian predators, nor

result in the trampling or destruction of riparian breeding habitat;

(2) Federally-approved projects that involve activities such as

discharge of fill material, draining, ditching, tiling, pond

construction, stream channelization or diversion, or diversion or

alteration of surface or ground water flow into or out of the wetland

(i.e., due to roads, impoundments, discharge pipes, stormwater

detention basins, etc.)--when such activity is conducted in accordance

with any reasonable and prudent measures given by the Service in

accordance with section 7 of the Act; and

(3) Livestock grazing that does not attract the brood parasitic

brown-headed cowbird or result in the destruction of riparian habitat

or the disturbance of breeding flycatchers.

Activities that the Service believes could potentially harm the

southwestern willow flycatcher and result in ``take,'' include, but are

not limited to:

(1) Unauthorized handling or collecting of the species;

(2) Destruction/alteration of the species' habitat by discharge of

fill material, draining, ditching, tiling, pond construction, stream

channelization or diversion, or diversion or alteration of surface or

ground water flow into or out of the wetland (i.e., due to roads,

impoundments, discharge pipes, stormwater detention basins, etc.);

(3) Livestock grazing that results in direct or indirect

destruction of riparian habitat;

(4) Activities such as continued presence of cattle and

fragmentation of flycatcher habitat that facilitate brood parasitism by

the brown-headed cowbird; and

(5) Pesticide applications in violation of label restrictions.

Questions as to whether specific activities will constitute a

violation of section 9 should be directed to Sam F. Spiller or Robert

M. Marshall at the Service's Ecological Services State Office, 2321

West Royal Palm Road, Suite 103, Phoenix, Arizona 85021 (Telephone 602/

640-2720)

National Environmental Policy Act

The Fish and Wildlife Service has determined that an Environmental

Assessment and Environmental Impact Statements, as defined under the

authority of the National Environmental Policy Act of 1969, need not be

prepared in connection with regulations adopted pursuant to Section

4(a) of the Act. A notice outlining the Service's reasons for this

determination was published in the Federal Register on October 25, 1983

(48 FR 49244).

References Cited

A complete list of all references cited herein, as well as others,

is available upon request from the Supervisor, Ecological Services

State Office in Arizona (see ADDRESSES above).

Author

The primary author of this rule is Robert M. Marshall, Ecological

Services State Office in Arizona (see ADDRESSES above).

List of Subjects in 50 CFR Part 17

Endangered and threatened species, Exports, Imports, Reporting and

record keeping requirements, and Transportation. [[Page 10715]]

Regulation Promulgation

Accordingly, part 17, subchapter B of chapter I, title 50 of the

Code of Federal Regulations, is amended as set forth below:

PART 17--[AMENDED]

1. The authority citation for Part 17 continues to read as follows:

Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C.

4201-4245; Pub. L. 99-625, 100 Stat. 3500; unless otherwise noted.

2. Section 17.11(h) is amended by adding the following, in

alphabetical order under Birds, to the List of Endangered and

Threatened Wildlife to read as follows:

Sec. 17.11 Endangered and threatened wildlife.

* * * * *

(h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------

Species Vertebrate population

--------------------------------------------------- Historic range where endangered or Status When listed Critical Special

Common name Scientific name threatened habitat rules

--------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * * * *

Birds

* * * * * * *

Flycatcher, southwestern Empidonax traillii, U.S.A. (AZ, CA, CO, NM, Entire................. E 577 NA NA

willow. extimus. NV, TX, UT).

* * * * * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------

Dated: February 16, 1995.

Mollie H. Beattie,

Director, Fish and Wildlife Service.

[FR Doc. 95-4531 Filed 2-24-95; 8:45 am]

BILLING CODE 4310-55-P