federal register - Center for Biological Diversity€¦ · southern Utah, Arizona, New Mexico, western Texas, southwestern Colorado, and extreme northwestern Mexico. Within this region,

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10693

MondayFebruary 27, 1995

Part III

Department of theInteriorFish and Wildlife Service

50 CFR Part 17Endangered and Threatened Species:Southwestern Willow Flycatcher; FinalRule

10694 Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018 AB97

Endangered and Threatened Wildlifeand Plants; Final Rule DeterminingEndangered Status for theSouthwestern Willow Flycatcher

AGENCY: Fish and Wildlife Service,Interior.ACTION: Final rule.

SUMMARY: The Fish and Wildlife Service(Service) determines the southwesternwillow flycatcher (Empidonax trailliiextimus) to be an endangered speciesunder the authority of the EndangeredSpecies Act of 1973, as amended (Act).The breeding range of this bird includessouthern California, southern Nevada,southern Utah, Arizona, New Mexico,western Texas, southwestern Colorado,and extreme northwestern Mexico.Within this region, the species isrestricted to dense riparian associationsof willow, cottonwood, buttonbush, andother deciduous shrubs and trees. Thishabitat was historically rare andsparsely distributed and is currentlymore rare owing to extensivedestruction and modification. Thesouthwestern willow flycatcher isendangered by extensive loss of habitat,brood parasitism, and lack of adequateprotective regulations. This ruleimplements Federal protection providedby the Act for the southwestern willowflycatcher. Designation of critical habitatfor the southwestern willow flycatcheris deferred while the Service gathersfurther comments and reconsiders theprudence of designation and theappropriate boundaries of any area to bedesignated.DATES: The listing of the southwesternwillow flycatcher is effective March 29,1995. Comments on the designation ofcritical habitat may be submitted untilApril 28, 1995.ADDRESSES: The complete file for thisrule is available for inspection, byappointment, during normal business

hours at Ecological Services StateOffice, U.S. Fish and Wildlife Service,2321 West Royal Palm Road, Suite 103,Phoenix, Arizona 85021.FOR FURTHER INFORMATION CONTACT: SamF. Spiller or Robert M. Marshall at theabove address (Telephone 602/640–2720).

SUPPLEMENTARY INFORMATION:

BackgroundThe southwestern willow flycatcher is

a small bird, approximately 15centimeters (cm) (5.75 inches) long. Ithas a grayish-green back and wings,whitish throat, light grey-olive breast,and pale yellowish belly. Two wingbarsare visible; the eye ring is faint orabsent. The upper mandible is dark, thelower is light. The song is a sneezy ‘‘fitz-bew’’ or ‘‘fit-za-bew,’’ the call a repeated‘‘whitt.’’

The southwestern willow flycatcheroccurs in riparian habitats along rivers,streams, or other wetlands, where densegrowths of willows (Salix sp.),Baccharis, arrowweed (Pluchea sp.),buttonbush (Cephalanthus sp.),tamarisk (Tamarix sp.), Russian olive(Eleagnus sp.) or other plants arepresent, often with a scattered overstoryof cottonwood (Populus sp.) (Grinnelland Miller 1944, Phillips 1948, Phillipset al. 1964, Whitmore 1977, Hubbard1987, 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 tobe rare, widely separated, small and/orlinear locales, separated by vastexpanses of arid lands. Thesouthwestern willow flycatcher hasexperienced extensive loss andmodification of this habitat and is alsoendangered by other factors, includingbrood parasitism by the brown-headedcowbird (Molothrus ater) (Unitt 1987,Ehrlich et al. 1992, Sogge et al. 1993,Muiznieks et al. 1994).

The southwestern willow flycatcher(Order Passeriformes; FamilyTyrannidae) is a subspecies of one of theten North American flycatchers in thegenus Empidonax. The willowflycatcher and alder flycatcher (E.

alnorum) were once considered a singlespecies, the Traill’s flycatcher (E.traillii). Some sources [AmericanOrnithologists’ Union (AOU) 1983,McCabe 1991] treat E. traillii and E.alnorum, and all their subspecies as asuperspecies, the ‘‘traillii complex’’.However, the two species aredistinguishable by morphology (Aldrich1951), song type, habitat use, structureand placement of nests (Aldrich 1953),eggs (Walkinshaw 1966), ecologicalseparation (Barlow and McGillivray1983), and genetic distinctness (Seutinand Simon 1988). The breeding range ofthe alder flycatcher generally occursnorth of the willow flycatcher’s range.

The southwestern willow flycatcher isone of five subspecies of the willowflycatcher currently recognized(Hubbard 1987, Unitt 1987, Browning1993) (Figure 1.). The breeding ranges ofthe widely distributed E. t. traillii andE. t. campestris extend across thenorthern United States and southernCanada, from New England and NovaScotia west, through northern Wyomingand Montana, and into BritishColumbia. Hubbard (1987) and Unitt(1987) treated E. t. campestris assynonymous with E. t. traillii, butBrowning (1993) considered themseparate subspecies (Figure 1.). Thesubspecies E. t. adastus breeds fromColorado west of the plains, westthrough the Great Basin States and intothe eastern portions of California,Oregon and Washington. The breedingrange of E. t. brewsteri extends from thecentral California coast north, throughwestern Oregon and Washington toVancouver Island. The breeding range ofthe southwestern willow flycatcher (E. t.extimus) includes southern California,southern Nevada, southern Utah,Arizona, New Mexico, and westernTexas (Hubbard 1987, Unitt 1987,Browning 1993). It may also breed insouthwestern Colorado, but nestingrecords are lacking. Records of probablebreeding E. t. extimus in Mexico are fewand are restricted to extreme northernBaja California del Norte and Sonora(Unitt 1987, Wilbur 1987).BILLING CODE 4310–55–M

10695Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations

BILLING CODE 4310–55–C


The willow flycatcher subspecies aredistinguished primarily by subtledifferences in color and morphology.Unitt (1987) noted that these differences‘‘* * * are minor, but differ little inmagnitude from those distinguishing thespecies E. traillii from E. alnorum. InEmpidonax, small differences inmorphology may mask large differencesin biology.’’

The subspecies E. t. extimus wasdescribed by A.R. Phillips (1948) froma collection by G. Monson from thelower San Pedro River in southeasternArizona. The taxonomy of E. t. extimuswas critically reviewed by Hubbard(1987), Unitt (1987), and Browning(1993). Hubbard (1987) gave a qualifiedendorsement of the validity of E. t.extimus, recommending continuedexamination of the taxonomy. Unitt(1987) found that E. t. extimus wasdistinguishable from other willowflycatchers by color, being paler, andmorphology (primarily wing formula)but not overall size. Browning (1993)also found that E. t. extimus wasdistinguishable as a more pale-coloredsubspecies. The song dialect of E. t.extimus may also be distinguishablefrom other willow flycatchers. Ratherthan the crisp, sneezy ‘‘fitz-bew’’ of thenortherly subspecies, E. t. extimus singsa more protracted, slurred ‘‘fit-za-bew,’’with a burry ‘‘bew’’ syllable (recordingsby M. Sogge and J. Travis). Thesubspecies E. t. extimus is accepted bymost authors (e.g., Aldrich 1951, Behleand Higgins 1959, Phillips et al. 1964,Bailey and Niedrach 1965, Oberholser1974, Monson and Phillips 1981, Harriset al. 1987, Schlorff 1990, Harris 1991).Section 3(15) of the Act and regulationsat 50 CFR 424.02(k) defines the term‘‘species’’ as any subspecies of fish orwildlife or plants, and any distinctpopulation segment of any vertebratespecies which interbreeds when mature.Based on the above information, theService has determined that E. t.extimus is eligible for protection underthe Act.

The southwestern willow flycatchernests in thickets of trees and shrubsapproximately 4–7 meters (m) (13–23feet) or more in height, with densefoliage from approximately 0–4 m (13feet) above ground, and often a highcanopy cover percentage. The diversityof 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 sitevegetation may be even- or uneven-aged,but is usually dense and structurallyhomogeneous (Brown 1988, Whitfield1990, Sogge et al. 1993, Muiznieks et al.1994). Historically, E. t. extimus nested

primarily in willows, buttonbush, andBaccharis, with a scattered overstory ofcottonwood (Grinnell and Miller 1944,Phillips 1948, Whitmore 1977, Unitt1987). Following modern changes inriparian plant communities, E. t.extimus still nests in native vegetationwhere available, but has been known tonest in thickets dominated by tamariskand Russian olive (Hubbard 1987,Brown 1988, Sogge et al. 1993,Muiznieks et al. 1994). Sedgwick andKnopf (1992) found that sites selected assong perches by male willow flycatchers(E. t. traillii/campestris) exhibitedhigher variability in shrub size than didnest sites and often included largecentral shrubs. Habitats not selected foreither nesting or singing were narrowerriparian zones, with greater distancesbetween willow patches and individualwillow plants. Nesting willowflycatchers of all subspecies generallyprefer areas with surface water nearby(Bent 1960, Stafford and Valentine 1985,Harris et al. 1987), but E. t. extimusvirtually always nests near surface wateror saturated soil (Phillips et al. 1964,Muiznieks et al. 1994). At some nestsites surface water may be present earlyin the breeding season but only dampsoil 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 WildlifeBiology, in litt.-1993). Ultimately, awater table close enough to the surfaceto support riparian vegetation isnecessary.

Defining a minimum habitat patchsize required to support a nesting pairof E. t. extimus is difficult. Throughoutits range, determining the capability ofhabitat patches to support southwesternwillow flycatchers is confused by thespecies’ rarity, unstable populations,variations in habitat types, and otherfactors. However, the availableinformation indicates that habitatpatches as small as 0.5 hectare (ha) (1.23acres) can support one or two nestingpairs. Sogge et al. (1993) foundterritorial flycatchers in habitat patchesranging from 0.5 to 1.2 ha (1.23 to 2.96acres). Two habitat patches of 0.5 and0.9 ha (1.23 and 2.2 acres) eachsupported two territories. Muiznieks etal. (1994) also reported groups ofterritorial E. t. extimus in habitatpatches of approximately one to severalhectares.

The nest is a compact cup of fiber,bark, and grass, typically with featherson the rim, lined with a layer of grassor other fine, silky plant material, andoften has plant material dangling fromthe bottom (Harrison 1979). It isconstructed in a fork or on a horizontalbranch, approximately 1–4.5 m (3.2–15

feet) above ground in a medium-sizedbush or small tree, with densevegetation above and around the nest(Brown 1988, Whitfield 1990,Muiznieks et al. 1994).

The southwestern willow flycatcher ispresent and singing on breedingterritories by mid-May, although itspresence and status is often confused bythe migrating individuals of northernsubspecies passing through E. t. extimusbreeding habitat [D. Kreuper, Bureau ofLand Management (BLM), unpubl. data].The southwestern willow flycatcherbuilds nests and lays eggs in late Mayand early June and fledges young inearly to mid-July (Willard 1912, Ligon1961, Brown 1988, Whitfield 1990,Sogge and Tibbitts 1992, Sogge et al.1993, Muiznieks et al. 1994). Somevariation in these dates has beenobserved (Carothers and Johnson 1975,Brown 1988, Muiznieks et al. 1994) andmay be related to altitude, latitude, andrenesting.

The southwestern willow flycatcher isan insectivore. It forages within andabove dense riparian vegetation, takinginsects on the wing or gleaning themfrom foliage (Wheelock 1912, Bent1960). It also forages in areas adjacent tonest sites, which may be more open (M.Sogge, National Biological Survey, pers.comm. 1993). No information isavailable on specific prey species.

The migration routes and winteringgrounds of E. t. extimus are not wellknown. Empidonax flycatchers rarelysing during fall migration, so that ameans of distinguishing subspecies isnot available (Blake 1953, Peterson andChalif 1973). However, willowflycatchers have been reported to singand defend winter territories in Mexicoand Central America (Gorski 1969,McCabe 1991). The southwesternwillow flycatcher most likely winters inMexico, Central America, and perhapsnorthern South America (Phillips 1948,Peterson 1990). However, the habitats ituses on wintering grounds areunknown. Tropical deforestation mayrestrict wintering habitat for this andother neotropical migratory birds (Finch1991, Sherry and Holmes 1993).

Breeding bird survey data for 1965through 1979 combined the willow andalder flycatchers into a ‘‘Traill’sflycatcher superspecies’’, because oftaxonomic uncertainty during the 15-year reporting period. These datashowed fairly stable numbers in centraland eastern North America but strongdeclines in the West, the regionincluding the range of the southwesternwillow flycatcher, and where the alderflycatcher is absent (Robbins et al.1986).


Unitt (1987) reviewed historical andcontemporary records of E. t. extimusthroughout its range, determining that ithad ‘‘declined precipitously,’’ and that‘‘although the data reveal no trend inthe past few years, the population isclearly much smaller now than 50 yearsago, and no change in the factorsresponsible for the decline seem likely.’’Data are now available that indicatecontinued declines, poor reproductiveperformance, and/or continued threatsfor most remaining populations (Brown1991, Whitfield and Laymon, Kern RiverResearch Center, in litt. 1993, Sogge andTibbitts 1992, Sogge et al. 1993,Muiznieks et al. 1994).

Previous Federal ActionsThe Service included the

southwestern willow flycatcher on itsAnimal Notice of Review as a category2 candidate species on January 6, 1989(54 FR 554). A category 2 species is onefor which listing may be appropriate butfor which additional biologicalinformation is needed. After solicitingand reviewing additional information,the Service elevated E. t. extimus tocategory 1 candidate status onNovember 21, 1991 (56 FR 58804). Acategory 1 species is one for which theService has on file substantialinformation to support listing, but forwhich a proposal to list has not beenissued because it is precluded at presentby other listing activity.

On January 25, 1992, a coalition ofconservation organizations (Suckling etal. 1992) petitioned the Service,requesting listing of E. t. extimus as anendangered species under the Act. Thepetitioners also requested emergencylisting and designation of criticalhabitat. On September 1, 1992, theService published a finding (57 FR39664) that the petition presentedsubstantial information indicating thatlisting may be warranted and requestedpublic comments and biological data onthe species. On July 23, 1993, theService published a proposal (58 FR39495) to list E. t. extimus asendangered with critical habitat, andagain requested public comments andbiological data on the southwesternwillow flycatcher.

Summary of Comments andRecommendations

In the July 23, 1993, proposed rule (58FR 39495) and associated notifications,all interested parties were requested tosubmit comments or information thatmight bear on whether to list thesouthwestern willow flycatcher. Thecomment period was originallyscheduled to close October 21, 1993,then was extended to November 30,

1993. Appropriate State agencies,county governments, Federal agencies,scientific organizations, and otherinterested parties were contacted andrequested to comment. Newspapernotices inviting public comment werepublished in the following newspapers;In California, Los Angeles Times, L.A.Watts Times, Kern Valley Sun, and SanDiego Union-Tribune; in Arizona,Arizona Daily Sun, Arizona Republic,Tucson Daily Citizen, White MountainIndependent, and Arizona Daily Star; inNew Mexico, Albuquerque Journal,Albuquerque Tribune, Santa Fe NewMexican, Carlsbad Current-Argus, SilverCity Daily Press; in Nevada, Las VegasSun; in Colorado, Durango Herald; inUtah, Daily Spectrum; and in Texas, ElPaso Times. The inclusive dates ofpublications were August 31 throughSeptember 13, 1993, for the initialcomment period and October 28through November 5, 1993, for thepublic hearings and extension of publiccomment period.

The Service held six public hearings.Because of anticipated interest in theproposed rule, the Service announcedits intention to hold at least three publichearings. In response to requests fromthe public, three additional hearingswere scheduled. A notice of the hearingdates and locations was published inthe Federal Register on October 18,1993 (58 FR 53702). Approximately 424people attended the hearings. About 17people attended the hearing in Tucson,Arizona; 27 in Flagstaff, Arizona; 10 inLas Cruces, New Mexico; 12 inAlbuquerque, New Mexico; 350 in LakeIsabella, California; and 8 in San Diego,California. Transcripts of these hearingsare available for inspection (seeADDRESSES).

A total of 3,102 written commentletters were received at the Service’sEcological Services State Office inArizona: 264 supported the proposedlisting; 2,650 opposed the proposedlisting; and 188 expressed neithersupport nor opposition, but eithercommented on information in theproposed rule, provided additionalinformation, or were non-substantive orirrelevant to the proposed listing.

Oral or written comments werereceived from 62 parties at the hearings:8 supported the proposed listing; 40opposed the proposed listing; and 14expressed neither support noropposition but provided additionalinformation, or were non-substantive orirrelevant to the proposed listing.

In total, oral or written commentswere received from 31 Federal and Stateagencies and officials, 17 local officials,and 3,116 private organizations,companies, and individuals. All

comments received during the commentperiod are addressed in the followingsummary. Comments of a similar natureare grouped into a number of generalissues.

Issue 1: The American Ornithologists’Union (AOU) did not list E. t. extimusin its latest Checklist of North AmericanBirds; Unitt (1987) could not distinguishE. t. extimus by color or morphology;genetic analysis is necessary todistinguish subspecies; significantdisagreement exists among scientistsregarding taxonomy, for example,McCabe (1991) did not recognize E. t.extimus; the willow flycatchersubspecies, in fact the North AmericanEmpidonax flycatcher species are toodifficult to distinguish to make itreasonable to list subspecies of thosespecies; hybridization of the willowflycatcher subspecies occurs; subspeciesare not worth listing; E. t. extimus is asubspecies of a very common species; E.t. extimus is not worth listing becauseit is one of nine common species in thegenus Empidonax; this subspecies andsubspecies in general are of minorecological value; their loss would beunimportant; there is little value inpreserving rare species/subspecies; andhistorical taxonomic questions mayconfuse population trend information.

Service Response: The Service hasdetermined that E. t. extimus is a validtaxon. The Service relies on the mostcurrent and authoritative data availablein making decisions regarding thevalidity of species, subspecies, ordistinct vertebrate population segments.These data include articles published inprofessional journals, agency reports,and other unpublished data provided byresearchers. For the southwesternwillow flycatcher, the Service reviewedthis information and found a majorityopinion that E. t. extimus is a validsubspecies. Authorities who criticallyexamined the taxonomy of E. traillii andrecognized E. t. extimus include Phillips(1948), Aldrich (1951), Hubbard (1987),Unitt (1987), and Browning (1993).Other authorities accepting thesubspecies include Behle and Higgins(1959), Phillips et al. (1964), Bailey andNiedrach (1965), Oberholser (1974),Monson and Phillips (1981), Harris et al.(1987), Schlorff (1990), Whitfield (1990),Brown (1991), Harris (1991), WesternFoundation for Vertebrate Zoology inlitt. 1993, University of California in litt.1993. The AOU (1983) did not listsubspecies of any bird, including thewillow flycatcher, in its 1983 Checklistof North America Birds. However, thisdoes not indicate a lack of recognitionof E. t. extimus, or for the concept ofsubspecies. The preface to the 1983Checklist states ‘‘The Committee


strongly endorses the concept of thesubspecies * * * and we wish to makeit clear that the omission of separatelistings of subspecies in this edition isnot a rejection of the validity or utilityof this systematic category * * *.’’

The Service noted McCabe’s (1991)consideration of the willow and alder(E. alnorum) flycatchers as a singlespecies, and his reluctance to recognizewillow flycatcher subspecies. McCabe(1991) provides a thorough review of thehistory of E. alnorum and E. trailliitaxonomy, and the questions ofecological, morphological, and song-type distinction on which thistaxonomic evaluation has been based.However, the Service agrees withSedgwick’s (1993) comments andMcCabe’s own observation that McCabe(1991) contrasts with the majorityopinion regarding taxonomy of thewillow and alder flycatchers.

After examining 305 study skins,Unitt (1987) found that while foursubspecies (E. t. traillii, E. t. adastus, E.t. brewsteri, and E. t. extimus) could betentatively separated by the ‘‘75 percentrule’’ using overall size (wing and taillengths and their ratios to one another),these criteria were not satisfactorilyconclusive. However, he found that thesubspecies could be satisfactorilydistinguished, under the ‘‘75 percentrule,’’ using color, wing formula(relative lengths of primary wingfeathers), or both. Browning (1993)examined 270 specimens and found thatall four subspecies, and a fifth (E. t.campestris) were distinguishable bycolor.

The Service acknowledges thattaxonomy of E. traillii races continues topose questions and may be revised inthe future. The Service has determinedthat E. t. extimus is a sufficientlydistinct entity to be listed under the Actat the very least as a distinct vertebratepopulation [50 CFR § 424.02(k)].However, the Service accepts themajority opinion that E. t. extimus is avalid subspecies and lists it as such.

The Service considers taxonomicdistinctness in assigning priorities forspecies listings, but not in determiningwhether or not to list species. The Actauthorizes listing of species, subspecies,or distinct population segments, all ofwhich have ecological significance.

Issue 2: The southwestern willowflycatcher is not a riparian obligatespecies. It also occurs in open prairiewoodlots, dry and brushy pastures, andbrushy fields or slopes. No surveys ofdry habitats have been done to proveriparian obligacy. The southwesternwillow flycatcher does not ‘‘invariably’’nest near surface water.

Service Response: The Service isunaware of any study, report, or speciesaccount that describes E. t. extimus asanything but a riparian obligate. Nocommenter provided data, studies, orreports indicating that E. t. extimusnests outside riparian habitats. Severalcommenters cited field guides whichdescribe the willow flycatcher (allsubspecies) as occurring ‘‘* * * indrier situations (than the alderflycatcher) * * *’’ (Peterson 1990),‘‘* * * on brushy slopes * * *’’(Robbins et al. 1983), and ‘‘* * * dry,brushy upland pastures * * *’’(National Geographic Society 1990). TheService believes that field guide speciesaccounts do not constitute the bestavailable scientific information onbiology, ecology or habitatrequirements. Field guide accounts tendto be brief and generalized, and in thiscase represent habitat use of otherwillow flycatcher subspecies, whichoccur in more mesic regions. Similarly,Barlow and McGillivray’s (1983)description of willow flycatchers (E. t.campestris/traillii) selecting ‘‘* * * amore xeric upland habitat * * *’’ inOntario, Canada, is not consideredrelevant to habitat selection of E. t.extimus in the desert Southwest. In thewetter climates of the north, uppermidwest, and northeast, habitatconditions of moist soil or surfacewater, supporting thickets of deciduousshrubs and trees, are not restricted toriparian areas. However, in the aridSouthwest where E. t. extimus occurs,these conditions are limited to riparianareas, usually in profound contrast tothe adjacent and prevailing desertconditions. Various authors (e.g., King1955) have noted that while willowflycatchers may nest away from riparianareas in the north and east, in aridregions (the ranges of E. t. brewsteri andE. t. extimus particularly) the species isrestricted to riparian habitats. Regardingthe presence of surface water during thebreeding season, new information wasprovided indicating that some nest siteshave surface water in close proximityearly in the breeding season, whichrecedes underground by the end of thebreeding season. At these sites, thewater table remains at least high enoughto sustain riparian vegetation. TheService is unaware of any surveysperformed in non-riparian habitatsspecifically to verify the absence ofnesting E. t. extimus. However, theService relied on local, State, andregional species accounts of distributionand habitat use, none of which describeoccurrence outside of riparian habitats.

Issue 3: The loss and modification ofsouthwestern riparian habitat is

overstated, poorly documented, anddoes not constitute a threat to theflycatcher; the statement that 90 percentloss of riparian habitat has occurred isinaccurate and an exaggeration; riparianhabitat has not decreased, but increasedas a result of diversions, irrigation, etc;habitat has increased, not decreased, inlocal area(s) over the past 20 years;riparian regeneration is approaching1,000 percent in southeastern Arizona;Hastings and Turner (1965) show thatcottonwood riparian habitat hasincreased in southeastern Arizona; theupper San Pedro River is recovered, not‘‘unsuitable and unoccupied’’ as theService claimed; because tamarisk hasincreased, and E. t. extimus usestamarisk, tamarisk invasion does notconstitute modification of habitat, butexpansion of habitat; populationdeclines in the past 20 years areconcurrent with improved riparianhabitats, so no correlation existsbetween trends in habitat andpopulations; the proposal fails tosupport claims that urban development,agriculture, and livestock grazing areharmful to the flycatcher.

Service Response: The Service hasdetermined that the documentation ofloss and modification of southwesternriparian habitats, cited in this final rule,is adequate. Regarding the ‘‘90 percentloss and modification’’ statement, theproposed rule stated that ‘‘* * * asmuch as 90 percent * * *’’ (emphasisadded) has been lost or modified. Theactual percentage lost or modified is notexpected to be consistent across theregion, but should vary with elevation,rainfall, geographic area, relative size ofdrainage system, and severity ofimpacts. Loss and modification may belesser at higher elevations, whereprecipitation is greater and evaporationless. In most major lower elevationdesert riparian systems, loss ormodification may in fact be near 100percent, e.g., the lower Colorado, lowerGila, lower Rio Grande, and lower SaltRivers. Because ‘‘modification’’ includesalterations in flow regimes, channelconfinement, changes in water quality,and floristic makeup of ripariansystems, the Service believes it is not amisrepresentation to state that up to 90percent of southwestern riparianecosystems have been lost or modified.

Commenters stating that riparianhabitat has not decreased, but increasedas a result of diversions and irrigation,presented no supporting information.The Service recognizes that somediversions, particularly unmaintainedirrigation ditches, sometimes supportriparian vegetation. However, theService believes diversion and irrigationresult in a net loss of riparian habitat.


Where riparian vegetation becomesestablished along irrigation systems, it isoften cleared away at regular intervals.Where it is not, it is sometimes becausean artificially created riparian/wetlandhabitat is being maintained asmitigation or compensation for loss ofnatural riparian habitat elsewhere.

The Service recognizes that in somelocal areas in recent decades, riparianhabitat has been rehabilitated orincreased, not decreased. However, theService accepts the consensus ofliterature cited in this rule that theoverall trend continues to be one ofhabitat loss.

Hastings and Turner (1965) and Bahre(1991) noted that riparian habitats werealready significantly altered by the turnof the last century. Hastings and Turner(1965) also noted that all majorwatercourses in southern Arizonasuffered entrenchment and becamemore ephemeral in flow inapproximately 1890. Land use practicesthat had already affected riparianhabitats in this Arizona-Mexico borderregion included livestock grazing,woodcutting, and water diversion;climatic changes may also havecontributed. The differences betweenthe historic and more recentphotographs show some riparianrecovery, concurrent with reductions inlivestock stocking levels from theirhighs in the late 1800’s. No data, orelaboration, were presented to supportstatements that riparian regeneration isapproaching 1000 percent insoutheastern Arizona.

As this final rules discusses, E. t.extimus sometimes nests in tamarisk,but does so at lower densities, andapparently at lower success rates than innative vegetation (Hunter et al. 1988,Sogge et al. 1993, Muiznieks et al.1994). Therefore, tamarisk invasionlikely represents replacement of nativehabitat with lower-quality habitat,rather than an increase in habitatavailability. Only in a few uniquesituations does tamarisk truly represent‘‘new’’ habitat. For example, in theGrand Canyon flycatchers nest in a‘‘new’’ riparian habitat, dominated bytamarisk (Carothers and Brown 1991).This new riparian habitat becameestablished in the historic flood-scourzone of the Colorado River, afterconstruction of Glen Canyon Dameliminated annual scouring floods.However, flycatchers nest in this area inlow numbers (Brown 1991, Sogge andTibbitts 1992, Sogge et al. 1993) andhave low nesting success. It isnoteworthy that by forming LakePowell, Glen Canyon Dam alsoinundated habitat in Glen Canyon. Thesouthwestern willow flycatcher was

described as a common nester in GlenCanyon prior to inundation (Behle andHiggins 1959, Behle 1985), indicatingthat this historic habitat was of higherquality than the new habitat in GrandCanyon.

Issue 4: The flycatcher has alwaysbeen a rare bird, so its rarity now is nochange from historical situations;historical specimens are few, indicatingthe bird was always rare; populationdata are insufficient to show decline;population data are suspect, developedby parties with agendas of land control/acquisition; the flycatcher is notdeclining in all areas; historicaltaxonomic questions may confusepopulation trend information; accuracyor existence of population trend data forthe last 50 years is questionable;population sampling techniques werenot discussed; these could bias trendstudies; population data are incomplete;the proposal relies on data reflectingloss of habitat rather thancomprehensive population trendanalysis; there are no recent collectionsof E. t. extimus from southern Arizonariparian areas.

Service Response: The Service agreesthat the flycatcher has probably alwaysbeen sparsely distributed, as a functionof the sparse distribution of its wetlandhabitat in a predominantly xeric region.However, sparse distribution and rarityare not necessarily equivalent. Atindividual locales the flycatcher mayoccur in considerable numbers, asindicated by Herbert Brown’s collectionof 36 nests near Yuma in 1902, and thepersistence of several populations ofconsiderable numbers (30–40 pairs) inrelatively small areas like the Kern RiverPreserve in California (Harris et al.1986, Whitfield 1990). Although E. t.extimus habitat is rare, where it ispresent nesting pairs may occur inrelatively high densities. Thisphenomenon has caused some authorsto describe E. t. extimus as something ofa colonial nester (e.g., Unitt 1987).

Regarding the lack of historic orrecent specimens available from variousparts of the bird’s range, the Servicenotes that specimen collection is largelya function of collecting activity, notsimple presence of the subject.

The Service agrees that, as with manynon-game species, population trend dataare incomplete. No wide scale, and fewlocal studies have been funded orundertaken to track this species throughtime. Comprehensive, long-termpopulation data are not necessarilyrequired for making listingdeterminations. Rather, these decisionsoften rest upon data on loss andmodification of habitat and otherthreats, which are reasonably assumed

to result in population declines. Inmany cases, population declines areinferred from decline in habitatavailability. However, in this and otherlisting determinations, the Service seeksto measure such inference againstwhatever population trend data areavailable. Regarding concerns oversources of these data, the Serviceendeavors to verify accuracy andcredibility of data. The reportspublished by government agencies,academic institutions, and professionaljournals on which this determination isbased are accepted as credible. Tointerpret population trends in the lightof changing taxonomic status, theService considered all information forwillow flycatchers in the current rangeof E. t. extimus to be relevant.

Issue 5: Livestock grazing is not athreat to E. t. extimus or its habitat;Montgomery et al. (1985) found 53singing birds in a grazed area in NewMexico; on Marine Corps Base CampPendleton, E. t. extimus is increasingwhere sheep graze; nest disturbance bycattle is unsubstantiated; southwesternflora evolved with large grazingungulates; the proposed rule lacksexamples of flycatcher status improvingwith reduction in livestock or improvedlivestock management; E. t. extimus isnot improving in areas with no grazing;the proposed rule equates any livestockgrazing with overgrazing, and fails todistinguish between overgrazing andwell-managed grazing; proper livestockmanagement is compatible with healthyriparian habitat; some level of livestockgrazing is compatible with/necessary forhealthy riparian ecosystems; willowsare brush, which cattle don’t eat, butcattle are blamed for both brushencroachment and brush destruction;cattle trample stream banks, whichallows water to escape, creating moreriparian habitat; livestock grazingprevents urbanization of land, whichwould have a greater impact on riparianhabitats.

Service Response: The proposed andfinal rules discuss overuse by livestockas a threat to E. t. extimus, throughimpacts on riparian habitat. The Servicerecognizes that what constitutes‘‘overuse’’ varies with differing riparianecosystems, elevation, type of livestock,seasonality of use, and other factors.The Service believes that some livestockgrazing regimes are likely to be foundcompatible with rehabilitation andmaintenance of E. t. extimus habitat.

Montgomery et al. (1985) did notdetermine whether the willowflycatchers they detected on grazed landwere resident E. t. extimus or migratingindividuals of other subspecies. Further,neither grazing intensity nor nesting


success were quantified, so that nocorrelations can be made. On CampPendleton, increases in E. t. extimuswere concurrent with livestock (sheep)grazing but also with an extensivecowbird trapping program (Griffith andGriffith 1993). Finally, as discussed inthis rule, examples exist of E. t. extimus(and other E. traillii subspecies)numbers and habitat increasing as aresult of grazing reductions or otherimprovements in livestock management.

The Service recognizes thatsouthwestern riparian ecosystemsevolved with native grazing ungulates(e.g., deer and elk). However, domesticlivestock do not forage, herd or move inthe same manner as native species.Further, elk occur at higher elevations ofthe Southwest, and are absent from thelowland river systems that constitutethe majority of E. t. extimus habitat.

Issue 6: Timber harvesting is not athreat to the flycatcher’s riparianhabitat.

Service Response: The proposed rulenoted that the petitioners claimedtimber harvest caused watershedchanges which could result in damageto riparian habitats through increasingintensity and frequency of floods. Thepetitioners presented no specificinformation on this claim. A number ofexperimental treatments onSouthwestern forested watersheds havedemonstrated increased peak and floodflows as a result of timber harvest (Tecle1991). The degree to which timberharvesting has affected riparian habitatsinhabited by the willow flycatcher,however, has not been quantified and isunknown. The Service did not implicatetimber harvesting in the proposed ruleas a major cause of riparian habitat loss.Rather, it pointed to that activity as oneof many factors potentially responsiblefor riparian habitat loss andmodification. Pending new informationdemonstrating otherwise, the Servicestill considers timber harvesting apotential threat to riparian habitatthrough loss and modification.However, the Service does not believethat this threat exists rangewide, nordoes it believe that timber harvestingalone is responsible for riparian habitatloss or the endangered status of thesouthwestern willow flycatcher.

All causal factors will be addressed inthe recovery planning process, andthrough the Act’s section 7 consultationprocess, through which Federal agencieswill be responsible for evaluating theeffects of activities such as timberharvest on the flycatcher’s riparianhabitat.

Issue 7: Water impoundments havebeen beneficial, not detrimental;fluctuating flows below dams are not

detrimental, in fact have increasedriparian habitat (Glen Canyon Damresulted in creation of riparian habitatin Grand Canyon); impoundmentsprotect habitat by preventingcatastrophic floods; the proposal hadinadequate discussion of waterimpoundments as threat.

Service Response: As discussedelsewhere in this final rule, waterimpoundments have a variety of effectson riparian habitats. The Service hasdetermined that, with respect to E. t.extimus, the net effect of theseinfluences is negative. For example,Glen Canyon Dam eliminated massiveannual scouring floods in the GrandCanyon. This resulted in thedevelopment of a new riparian zonedominated by tamarisk (Carothers andBrown 1991). However, flycatchers nestthere in very low numbers and with lownesting success (Brown 1991, Sogge andTibbitts 1992, Sogge et al. 1993). Incontrast, E. t. extimus was described asa common nester in Glen Canyon (Behleand Higgins 1959, Behle 1985), prior toits inundation by Lake Powell.

Issue 8: Comments concerning theecology of cowbirds and cowbirdparasitism included the following:Breeding Bird Survey (BBS) dataindicate that cowbirds have declined,not increased; the claim that cowbirdsare associated with livestock is notsupported; cowbirds are associated withdeer and elk, not cows; the cowbirdthreat is a natural one; there isinconclusive evidence that cowbirdincreases are directly connected withlivestock grazing; cowbird parasitism ofE. t. extimus is known in areas withoutlivestock grazing (e.g., Grand Canyon,Kern River); there is no correlationbetween livestock grazing in riparianareas and cowbird parasitism; Taylor(1986) showed that cowbirds were mostabundant in areas with long-termlivestock exclusion; because flycatchersand cowbirds are positively associated(they tend to occur together), flycatcherscan coexist with cowbirds; there isinconclusive evidence that cowbirdparasitism is responsible for declines innesting success; cowbirds haveincreased as a result of increases in birdfeeders, campgrounds, etc. andincreases in wintering food/habitat; theproposed rule cited no studies thatdocumented cowbird parasitism of E. t.extimus; citations regarding parasitismof other species are irrelevant. Section4(a)(1)(E) of the Act allows listingspecies because of ‘‘* * * natural ormanmade factors affecting its continuedexistence * * *.’’

Service Response: Cowbird numbersappear to be declining only in thenortheastern United States and

southeastern Canada. Through the 27years of the BBS, cowbird populationshave remained fairly stable, with a smallincrease in the 1970’s, small decrease inthe 1980’s, and slight increase in recentyears; however, the West hasexperienced a marked populationincrease over the last five years(Wiedenfeld 1993).

The association of cowbirds withdomestic livestock is detailed in thesources cited in this final rule. TheService has neither found nor beenprovided information indicating thatcowbirds are associated with deer orelk. Other factors, including habitatfragmentation and urban/suburbanfeeding, are likely to have contributed toincreases in cowbirds. These causalfactors will be important to address inthe section 7 consultation process andthe development of recovery actions.However, it is the threat of parasitism,regardless of cause, that in partnecessitates listing.

Where high parasitism rates are foundin E. t. extimus nesting locations inareas with no livestock grazing at thenest site, there have been livestocknearby that provide feeding sites inclose enough proximity to facilitatecowbird parasitism. Cowbirds maydisperse up to 7 kilometers (km) fromtheir daily feeding/roosting sites to areaswith host species (Rothstein et al. 1984).At the Kern River Preserve, the riparianhabitat supporting E. t. extimus is notgrazed, but the immediately adjacentlands are. Similarly, although livestockgrazing does not occur in Grand CanyonNational Park, open range grazing andan introduced bison herd occur onadjacent lands. Further, cowbirdsconcentrate at pack animal corrals atvarious points within the National Park(Johnson and Sogge 1993). Thus,flycatcher habitat may be ungrazed butstill be affected by cowbirds, by havinglivestock concentrations nearby to serveas cowbird feeding sites.

Cowbirds and E. t. extimus arepositively associated because cowbirdsrequire, and therefore associate with,prospective hosts. The Service finds thatextensive information indicates cowbirdparasitism negatively affects thesouthwestern willow flycatcher. Thisinformation includes specific examplesof parasitism of E. t. extimus, cited inthis rule, and examples of the effects ofcowbird parasitism on other rare speciesof limited habitat. Recent informationcontinues to document high parasitismrates for E. t. extimus (Sogge et al. 1993,Muiznieks et al. 1994), and increases inflycatcher reproduction or populations,concurrent with reductions in cowbirdnumbers (Griffith and Griffith 1993, M.Whitfield in litt.—1993).


Issue 9: Tamarisk is not an invaderspecies, but a successional stage,becoming established on recently-scoured areas; livestock do eat tamariskfor its salt content; the Service needs toclarify the positive and negativecharacteristics of tamarisk; tamariskincreases habitat availability, in factprovides high-quality bird habitat.

Service Response: The Service foundno information, and was not providedany information by commenters,indicating that tamarisk is primarily asuccessional stage vegetation type,rather than an invasive exotic. This finalrule presents an updated discussion oftamarisk ecology, supported byadditional literature references. TheService concurs with the consensusamong published authorities thattamarisk is an invasive, usuallydominant exotic plant, not asuccessional species. Commenters thatstated livestock eat tamarisk for its saltcontent provided no supportinginformation. The Service’sunderstanding of the literature is thatcattle prefer native species overtamarisk for forage.

As discussed in this rule, E. t. extimushas been documented nesting intamarisk at elevations aboveapproximately 625 m (2000 feet). Ratherthan attempt to present criteria here forwhen tamarisk eradication presents athreat or a positive recovery action, theService will address this issue on a case-by-case basis through the section 7consultation process with other Federalagencies. This will allow Federalagencies the flexibility to considerindividual cases in the light of thespecific circumstances surroundingeach one.

Although Brown and Trosset (1989)suggested that tamarisk provided an‘‘ecological equivalent’’ to nativevegetation, they qualified this statement.They noted that their study involvedsmall sample sizes, and that theirmethods differed from Whitmore’s(1975, 1977), which was their basis forcomparison with native riparianhabitats. Further, Brown and Trosset(1989) noted that this ‘‘ecologicalequivalent’’ function may be mostsignificant where tamarisk becameestablished where no native riparianvegetation existed previously (e.g., theColorado River in Grand Canyon).

Issue 10: Herbert Brown’s collectionof 36 nests with eggs from the lowerColorado River, in 1900 and 1902,indicates overcollection for science mayhave caused declines.

Service Response: The effects ofBrown’s collections on populations over90 years ago are unknown. These effectsmay have been significant. However,

Brown’s collections themselves maysuggest that populations at that timecould sustain such collecting pressure.The origin of Brown’s collections fromseveral specific locales suggests that E.t. extimus was an abundant nesting birdin the area of the confluence of the Gilaand Colorado rivers. Collection of 36nests would have impactedreproduction alone, only for 1902, whenall but one of the nests was collected.Considering continued habitat loss, andincreasing cowbird populations since1902, the Service does not believe thatBrown’s collection of 36 nests with eggsin 1900 and 1902 significantly affects E.t. extimus populations in 1995.However, the Service believes thatcurrent flycatcher populations areunlikely to be able to sustain collectingpressures like Brown’s activities of1902. In 1993, extensive surveys of theregion of Brown’s collections locatedonly four to five territories (Muizniekset al. 1994).

Issue 11: Drought has impactedhabitat.

Service Response: The Servicerecognizes that extended droughts arelikely to have impacted E. t. extimusthrough habitat reduction. This naturalphenomenon and human-inducedhabitat impacts may exacerbate oneanother’s effects on E. t. extimus habitat.

Issue 12: Predators such as snakes,hawks, ravens, grackles, and domesticcats are threats to E. t. extimus.

Service Response: The Service agreesthat these constitute potential predatorsof songbirds, including E. t. extimus.While predation would not normally beexpected to be a major threat to theflycatcher, its populations may be solow currently that they cannotwithstand normal predation. Further,several of these types of predation maybe facilitated by habitat alteration orother human actions. Therefore, theService will address predation inrecovery planning, and other Federalagencies should consider the effects oftheir actions on some of these forms ofpredation.

Issue 13: Hikers, elk, deer, and beaverare threats to flycatcher nests andhabitat; listing would cause restrictionson fishing and water recreation.

Service Response: No information wasprovided to support statements thathikers constitute a threat to E. t.extimus. This rule briefly discussespossible impacts of recreation on E. t.extimus and its habitat. These impactsare expected to be primarily effects onvegetation through soil compaction,clearing vegetation, and creating trails.Because E. t. extimus is not a timidspecies, disturbance is expected to be animpact only when continuous intrusive

activities take place near habitat, orwhen recreation takes place within oradjacent to the nest stand. Because neststands tend to be very dense, virtuallyimpenetrable thickets, often withswampy conditions, recreationalimpacts are not expected to occur often.

Elk and deer use riparian habitats forforaging, but generally behavedifferently than domestic livestock.They tend not to occur in largeconcentrations and remain in riparianareas for long periods like domesticcattle. The Service is aware that elk canimpact riparian systems when theirnumbers reach high levels. However, elkare lacking from the majority ofsouthwestern willow flycatcher habitats,because these riparian areas occur atlower elevations than elk. Beaver cutand use willow and cottonwood, butmay also be important in creating quiet-water riparian habitats by dammingsmaller and steeper creeks.

Issue 14: The presence of unoccupiedhabitat indicates that E. t. extimus is notcurrently habitat limited.

Service Response: As discussed inthis rule, the Service has determinedthat E. t. extimus has suffered extensivehabitat loss, which is complicated bythe current low number of flycatchers,and reduction of reproductive outputdue to brood parasitism by brown-headed cowbirds. The current existenceof apparently suitable habitat that is notoccupied by E. t. extimus more likelyindicates that its numbers are too low tofill all available habitat. Further, habitatexists in isolated, fragmented patches.With low population numbers andinhibited reproduction, E. t. extimusmay be unable to maintain localpopulations, much less be able todisperse and colonize unoccupiedlocales.

Issue 15: Cowbird parasitism is themain threat to E. t. extimus, not habitatloss; cowbird control is the primaryrecovery need, not habitat protection;cowbird trapping would eliminate theneed for designating critical habitat; theService should implement and fundcowbird control programs instead oflisting.

Service Response: The Service hasdetermined that cowbird parasitism isone of several primary threats to E. t.extimus, which also includes the lossand modification of habitat. Cowbirdparasitism and loss and modification ofhabitat are interrelated. Cowbirdparasitism is a function not just ofcowbird abundance, but also habitatquality. Potential host species indegraded, fragmented habitat are moresusceptible to nest parasitism than thosenesting in larger tracts of dense,contiguous habitat. Cowbird parasitism


will probably remain an imminentthreat until habitat rehabilitation isaccomplished. The Serviceacknowledges that cowbird controlshould be an immediate, high priorityrecovery action. However, cowbirdcontrol is a ‘‘stop-gap’’ action.Rehabilitating riparian habitat to makeE. t. extimus and other riparian birdsless susceptible to cowbird parasitismwill be necessary for a long-termsolution. Ultimately, the ranking ofthreats in order of severity is notrelevant to the listing question. It isbecause a number of ofteninterdependent threats exist that listingE. t. extimus is necessary. Rankingthreats in order of severity andaddressing them accordingly will bepart of the recovery process.

Issue 16: Willow flycatchers nestingin the northern States, Alaska, andCanada are subspecies other than E. t.extimus. The boundaries of the breedingrange of E. t. extimus should beexpanded to include the Santa YnezRiver in California, and the Green andColorado River systems in west-centralUtah; E. t. extimus does not occur inUtah, Colorado, or the Carson NationalForest in northern New Mexico; thewillow flycatcher is common in thenorthern States, Alaska, Canada, most ofthe U.S., Mexico and Panama; cautionshould be exercised in defining rangelimits of the subspecies, includingelevational limits.

Service Response: Two primaryauthorities (Unitt 1987, Browning 1993)provide the range limits of E. t. extimusidentified in this rule (see Figure 1). TheService also considered otherinformation, such as historical nestingrecords, habitat characteristics, andproximity to neighboring populations ofE. t. extimus or other willow flycatchersubspecies. Using this information, theService provisionally defines thenorthwestern limit of the subspecies’range to be the Santa Ynez River inCalifornia. Willow flycatchers nestingalong the Santa Ynez River occupylowland riparian habitat similar to othercoastal California locations of E. t.extimus, and few willow flycatcher (i.e.,E. t. brewsteri) nesting locales areknown in coastal California for aconsiderable distance north of the SantaYnez River.

Browning (1993) found no evidence ofintergrades between E. t. extimus and E.t. adastus in Utah. The northern limit ofE. t. extimus in Utah is believed tocorrespond closely to the areacomprising the following counties:Garfield, Kane, San Juan, Washington,and Wayne. This area takes in stretchesof riverine riparian habitat in southernUtah that have historical records of

flycatchers and that still have potentialwillow flycatcher habitat.

The Service recognizes thattaxonomic questions may ariseconcerning flycatchers occupying somehigh-elevation locales within the rangeof E. t. extimus. Because the geneticrelatedness of willow flycatchersbreeding at some high elevation areas,such as the White Mountains ofArizona, may be substantial, willowflycatchers in those locales should beconsidered E. t. extimus until furtherresearch demonstrates otherwise.Protection of these breeding groupscould be critical for populationrecovery, immigration, and exchange ofgenetic material within a highly-fragmented landscape.

Issue 17: It is inappropriate to usedata from E. t. brewsteri and E. t.adastus to support listing E. t. extimus;information cited on livestock damagingnests comes from other subspecies.

Service Response: The Servicecarefully considered the propriety ofusing information on other willowflycatcher subspecies in evaluating thelisting question for E. t. extimus. Inapplying such information, the Serviceconsidered ecological similarities anddissimilarities between the subspecies.The Service believes that data fromother subspecies are applicable in somecases, but not others. The Service hasidentified which subspecies provideddata sources throughout the proposedand final rules. The phenomenon oflivestock damaging nests and/orcontents through physical contact isknown for willow flycatcher subspeciesother than E. t. extimus. This threat wasnoted to recognize that the potentialexists, where nests occur low enough invegetation or in other vulnerablelocations, that livestock, humans, orother animals may contact them or thenest plant.

Issue 18: Habitat in California was lostto urbanization, not livestock; theproposed rule had inadequatediscussion of urban and suburbandevelopment as a threat; urbandevelopment is not a threat to somepopulations.

Service Response: Loss andmodification of the riparian habitat of E.t. extimus is the result of numerousfactors, discussed in depth in this rule.Not all these factors have affected allriparian habitats, and some rare habitatsremain unaffected. Further, the degreeto which these factors influence riparianhabitat varies across the landscape.Urban and suburban development hascertainly impacted some E. t. extimushabitats. These impacts may result fromdirect encroachment and channelizationof riparian habitats, as in coastal

southern California and central Arizona.Urban and suburban development alsoincrease demands on river systems forwater and hydropower. Thus,expanding urban centers can result indewatering or alteration of ripariansystems tens or hundreds of miles away.For example, the water and powerdemands of Los Angeles, Phoenix andLas Vegas result in effects on theColorado River hundreds of miles fromany of these cities.

Issue 19: The primary threat to E. t.extimus is loss of wintering habitat inCentral and South America, or otherfactors along migration routes; theproposed rule contained insufficientinformation on migration studies;protecting breeding grounds is notlogical, because E. t. extimus spendseight months of the year in migration oron wintering grounds.

Service Response: Although tropicaldeforestation possibly may restrictwintering habitat of the willowflycatcher, the best available currentinformation on the subject suggestsotherwise. The limited data on willowflycatcher wintering habitat indicatesthat this species uses ‘‘* * * brushysavannah edges and second growth’’ inCosta Rica (Stiles and Skutch 1989); inPanama it has been documented in‘‘shrubby areas’’ (Ridgely 1981); and inSouth America it has been documentedin ‘‘* * * shrubby clearings, pastures,and lighter woodland’’ or ‘‘* * * onislands with early successional growth’’(Ridgely and Tudor 1994). Givenexisting land use practices in Centraland South America, which arecharacterized by conversion of old-growth forested habitat to agriculturaland second-growth habitats, few if anyof the winter habitat types in whichwillow flycatchers have beendocumented should currently be injeopardy.

Issue 20: The Service cannot definenesting habitat; habitat requirements arepoorly understood; the proposed rule’sdescription of nesting habitat is flawedand inadequate to direct management;the minimum patch size necessary tosupport a nesting pair of E. t. extimusis 1 to 1.5 hectares.

Service Response: The Servicebelieves the proposed rule and this finalrule accurately compile and summarizethe existing information on E. t. extimusnesting habitat, and that information issufficient to identify, conserve, andrecover the riparian ecosystem of whichE. t. extimus is a part. Habitat patchesoccupied by E. t. extimus varysomewhat in size, floristic composition,vegetation structure, and type ofwetland. Therefore, the Service believesit is inappropriate and inaccurate to


narrowly define suitable habitat interms of plants per unit area, vegetationdensity, specific plant communitycomposition, type and volume ofsurface water, and patch size. TheService has no information to indicateinaccuracy or inadequacy of the habitatdescription presented in this rule.Specifically regarding patch sizes, oneto two E. t. extimus pairs have beenobserved nesting in habitat patches of0.5 ha (Sogge et al. 1993, Sogge et al.unpubl. 1994 data); therefore 1.0 to 1.5ha is not an accurate estimate of theminimum patch size needed to supporta single nesting pair.

Issue 21: Habitats used by nestingpairs differ from those used by single,unmated, wandering, or migrantflycatchers; the latter face minimalthreats and are not essential toconservation of the species.

Service Response: The commentersprovided no data supporting thestatement that habitats used by unpairedE. t. extimus differ from nesting habitat,and the Service found no indication ofthis in the available literature. Unmated,resident E. t. extimus have been foundin habitats identical to nearby habitatsoccupied by nesting pairs (Sogge andTibbitts 1992, Sogge et al. 1993). TheService believes that single, unmated E.t. extimus also face threats of habitatloss, and that conservation of theseindividuals is essential to theconservation of the species, particularlyat the low current numbers offlycatchers.

Issue 22: Listing constitutes single-species management that will damageother species; E. t. extimus habitat isincompatible with habitat needs of otherlisted and sensitive species, particularlythe spikedace and loach minnow.

Service Response: The purposes of theAct are to provide a program for theconservation of threatened andendangered species and to conserve theecosystems upon which threatened andendangered species depend. The Servicebelieves that managing for E. t. extimusand other listed riparian and aquaticspecies accomplishes this purpose, tothe mutual benefit of listed andnonlisted species alike. The intent ofthis listing is to conserve and recover E.t. extimus and the riparian and aquaticecosystems of which it is a part.

The primary constituent elements ofcritical habitat described for thespikedace (59 FR 10906) and loachminnow (59 FR 10898) are not inconflict with the habitat requirementsfor the southwestern willow flycatcher,and are not in conflict with the primaryconstituent elements of its proposedcritical habitat (58 FR 39495). The fishesrequire ‘‘a healthy, intact riparian

community,’’ which will also benefit E.t. extimus and other riparian andaquatic species. The spikedace, loachminnow, and E. t. extimus all requiresurface water and/or a high water table,a low to moderate stream gradient, andperiodic flooding. The fishesspecifically require a ‘‘natural,unregulated hydrograph,’’ which theService believes would also benefit theflycatcher. These fish also requiremoderate to high bank stability;maintenance of the riparian vegetationon which E. t. extimus depends willprovide such bank stability. The Servicedoes not view management for E. t.extimus, spikedace, and loach minnowas mutually exclusive, but as mutuallybeneficial.

Issue 23: Floods regenerate habitat,they do not destroy it; floods destroyhabitat; floods, not livestock, causedmuch of riparian degradation; theproposed rule is confusing andcontradictory on the role of floods as athreat or necessary ecological function.

Service Response: The proposed rulestated that ‘‘Its habitat rarity, and small,isolated populations make theremaining E. t. extimus increasinglysusceptible to local extirpation throughstochastic events such as floods * * *.In early 1993, catastrophic floods insouthern California and Arizonadamaged or destroyed much of theremaining occupied or potentialbreeding habitat. Historically, thesefloods have always destroyed habitatbut were also important events inregenerating cottonwood-willowcommunities.’’

It is important to note that E. t.extimus is threatened by stochasticevents like floods because of its currentrarity and isolated nature ofpopulations. If the species existed athealthy population levels, and if itsriparian habitat were not greatlyreduced, these natural stochastic eventswould not constitute threats. The 1993flood events referred to wereextraordinary in nature, describedregionally as 500-year floods. Therefore,they do not typify flood events in theriver systems involved. Further, whilenatural flood events are expected todestroy some flycatcher habitat, they arealso crucial for regenerating naturalriparian nesting habitat. In a healthysystem where riparian vegetation isabundant and the stream channel is noteroded or destabilized, destruction andregeneration are balanced and habitat isgenerally available. Only when riparianvegetation is severely reduced and thestream channel and watershed aredestabilized are riparian and aquaticspecies threatened by the natural, short-

term habitat losses resulting fromflooding.

Issue 24: To manage for E. t. extimus,the Service will enforce or has proposeda fenced livestock-free corridor.

Service Response: The Service hasneither proposed nor been consultedregarding a fenced, livestock-freecorridor established along riparian areason State, Federal, or private lands.

Issue 25: Beneficial land managementpractices should be recognized anddiscussed; the proposed rule fails toacknowledge that some habitats areprotected from urban development.

Service Response: The Servicerecognizes that some managementpractices are beneficial. Some practiceshave protected or improved habitat,resulted in expanded populations, and/or improved reproduction. The Servicewill look to these beneficial landmanagement practices as importantexamples in the recovery planningprocess. However, in making a listingdetermination the Service must considerthe situation across the species’ entirerange. It is this overall perspective thatdrives the listing decision. Althoughsome nesting groups of E. t. extimusmay be safe, stable, or perhaps evenincreasing, the Service has determinedthat overall the species is endangered.

Issue 26: Existing regulatorymechanisms are adequate, including:the Migratory Bird Treaty Act (MBTA);State listings for Arizona, New Mexico,and California; section 404 of the CleanWater Act; Bureau of Land Managementand Forest Service policies; ExecutiveOrders 11988 and 11990; protection ofriparian habitat due to presence of otherlisted species; private and/orcooperative management plans at localareas.

Service Response: The Serviceconsidered these regulatory mechanismsand management plans, and determinesthat overall existing regulatorymechanisms are insufficient to conserveand recover E. t. extimus in the face ofthe primary threats of loss andmodification of habitat and cowbirdparasitism. A full discussion of Federaland State protection is found in thisdocument under Factor D: ‘‘Inadequacyof existing regulatory mechanisms’’.

The Service recognizes that somelocal management plans benefit andconserve E. t. extimus and its habitat.Examples include management of theBureau of Land Management’s SanPedro Riparian National ConservationArea (SPRNCA) in Arizona, where sixyears of livestock exclusion haveresulted in significant restoration ofriparian habitats and increases in birdsassociated with habitats similar to E. t.extimus (Krueper 1993). Willow


flycatchers have not yet returned totheir historical locations on theSPRNCA but may soon. Habitatprotection and cowbird management atThe Nature Conservancy’s Kern RiverPreserve and on Marine Corps BaseCamp Pendleton in California haveimproved habitat and reduced broodparasitism pressures for resident E. t.extimus (Griffith and Griffith 1993).Wetland management at Bosque delApache National Wildlife Refuge inNew Mexico is apparently sustaining asmall population of flycatchers. Whilethese actions are beneficial, theyprovide for E. t. extimus only at severallocales. Further, long-term continuationof these management actions is notassured.

Provisions of section 404 of the CleanWater Act do not specifically protect E.t. extimus or its habitat, but do providesome protection to the aquatic andriparian ecosystems of which it is a part.Section 404 of the Clean Water Act alsoprovides for mitigation of destruction ofthese habitats, however, allowing eventemporary destruction of riparianhabitat is not consistent with theimmediate conservation needs of E. t.extimus.

Issue 27: The Service did not use thebest available scientific or commercialinformation in making thisdetermination; the Service presentedinsufficient and inconclusiveinformation to support listing; theproposed rule used information whichwas general, incomplete, and originatedwith other flycatcher subspecies; theproposed rule was premature; theService did not adequately solicitinformation and public input; scientific,economic, biological, hydrological andbotanical data must support listing; howdoes the Service know the scientificinformation supporting listing wasright?

Service Response: The Servicecanvassed the published literatureregarding the taxonomy, ecology, andbiology of the southwestern willowflycatcher, and the threats to it and itshabitat. Because numerous and complexphenomena and processes wereinvolved, this information ranged fromgeneral (e.g., wide scale trends inriparian habitat) to very specific (statusof nesting groups). The Service believesit used the best available information,and has determined that thisinformation is adequate to supportlisting. The Service evaluates sourcesbefore using or discounting information.In general, the Service expects thatpublications in peer-reviewed scientificjournals, reports from land and resourcemanagement agencies, and dissertationsor reports from academic or research

institutions have undergone technicalreview. Other information sources areconsidered more anecdotal, and theService seeks to confirm suchinformation before using it.

Issue 28: The Service should complywith the National Environmental PolicyAct (NEPA) by completing anEnvironmental Impact Statement (EIS),and comply with 40 CFR 1506 to reduceduplication between NEPA and Stateand local requirements; the Serviceshould comply with 40 CFR 1508.20 tocompensate for producing substituteresources or environments; the Serviceshould engage in joint planning withlocal governments under NEPAregulations.

Service Response: As noted in thisfinal rule, the Service has determinedthat an Environmental Assessment, asdefined under the authority of NEPA,need not be prepared for listing actions.A notice outlining the Service’s reasonsfor this determination was published inthe Federal Register on October 25,1983 (48 FR 49244). Because of thisdetermination, an EIS also need not beprepared. Also because of thisdetermination, reduction of duplicationbetween the NEPA process and Stateand local agencies, and joint planningbetween those agencies and the NEPAprocess, are rendered moot.

Issue 29: The proposed rule violatesthe Regulatory Flexibility Act; noRegulatory Impact Analysis/Assessmentas required under Executive Orders12291 and 12866 was completed; it alsomay be inconsistent with the mandatesof other agencies.

Service Response: Decisions on listingand reclassification under the Act aremade based on five factors defined insection 4(a)(1) of the Act. These fivefactors are discussed in this rule, as theyrelate to E. t. extimus. The Act requiresthe Service to consider only scientificand commercial information relating tothese five factors in making listingdeterminations, not economicinformation. Economic information isconsidered in designating criticalhabitat, which is not part of this rule.Therefore, compliance with theRegulatory Flexibility Act and ExecutiveOrders 12291 and 12866 is not an issuefor this action, but will be addressed ifa critical habitat designation is made(H.R. Conf. Rep. No. 835, 97th Cong., 2dSess. 20 (1982); accord, S. Rep. No. 418,97th Cong., 2d Sess. 4 (1982)).

Where conservation and recovery ofthreatened and endangered species isinconsistent with other mandates ofFederal agencies, processes undersection 7 of the Act serve to evaluateprojects arising from those mandates,with regard to protection of listed

species. However, section 2(c) of the Actrequires all Federal departments andagencies to conserve listed species andfurther the purposes of the Act.

Issue 30: The Service should completea Takings Implications Assessment priorto listing/designating critical habitat.

Service Response: The Service willcomplete a takings analysis for any finaldesignation of critical habitat incompliance with Executive Order 12630and the Attorney General’ssupplemental guidelines issued June 30,1988. In accordance with thoseguidelines and Interior Departmentpolicy, this analysis will be completedafter listing, not as part of considerationof the listing determination itself.

Issue 31: Requests were received forlocal public hearings.

Service Response: The proposed rulestated that three public hearings wouldbe held. Because of many requests foradditional hearings, a total of six publichearings were held. Regulations at 50CFR 424.16(c)(3) require the Service tohold one public hearing if requested.

Issue 32: The time allowed for publiccomments was inadequate; the proposalshould have been subjected to peerreview.

Service Response: The Service isrequired to accept public comments forat least 60 days regarding proposals tolist and/or designate critical habitat (50CFR 424.16(c)(2)). In this case theService initially announced a 90-daypublic comment period, then extendedthat another 40 days for a total of 130days (July 23, 1993 through November30, 1993). Public comment periods andpublic hearings are the mechanisms bywhich the Service receives input fromall interested parties, includingscientific peer review.

Issue 33: Listing would requireprivate property owners to consult withthe Service on their actions; listing and/or designating critical habitat constitutetake of private property rights; adversemodification of critical habitat would beprohibited on private lands; the Servicefailed to notify the affected public of theconsequences of adverse modification ofcritical habitat; listing and/ordesignating critical habitat may affectcivil rights.

Service Response: Listing does notrequire private property owners toconsult with the Service on actionswhich may affect a listed species.However, section 7 of the Act doesrequire Federal agencies to consult onactions which they fund, permit, orcarry out if those actions may affect alisted species or adversely modifycritical habitat. Any potential take ofprivate property will be analyzed incompliance with Executive Order 12630


(see Issue 30). As discussed later (Issue35), because critical habitat is not beingdesignated with this rule, commentsregarding critical habitat will beaddressed during subsequent actionsregarding critical habitat.

Issue 34: Requests were received to beon a mailing list for all actions relatingto this issue or to be provided personalnotification of a final decision.

Service Response: The Service tries tomaintain mailing lists for specific issueswhenever possible. However, whenlarge numbers of parties request to be onsuch lists, it becomes logistically andfinancially unfeasible to mailinformation to each party. This issue isone of those, and the Service must relyto some degree on mass communicationforums like news releases, publicnotices in newspapers, and publicationsin the Federal Register.

Issue 35: Numerous comments werereceived regarding critical habitat.

Service Response: Critical habitat forE. t. extimus is not being designatedwith this rule; therefore, the aboveissues are not addressed here.Designation of critical habitat is beingdeferred while the Service furtherconsiders the extent to whichdesignation is appropriate. Issuespertaining to this designation will beaddressed when a final decision is madewith regard to the critical habitatproposal.

Issue 36: Numerous comments werereceived regarding recovery of E. t.extimus, including: the Service has norecovery plan for E. t. extimus; theproposed rule failed to identify recoverygoals for habitat, flycatcher numbers,and flycatcher distribution; theproposed rule failed to identify whatactions will be used to achieve recovery;a recovery plan should address controlof cowbird parasitism, nest damage bylivestock, tamarisk eradication,wintering habitat, monitoringpopulations, protection of public andprivate lands from fire; cowbirdparasitism cannot be addressed bylisting and designating critical habitat;cowbirds are not easily controlledwithout sacrificing flycatchers and/orimpacting habitat; the proposed rulecontained no livestock managingstrategy; rotating livestock will allowhabitat enhancement/recovery; thefactors affecting riparian habitats arenumerous and complex; failure toaddress all could be futile or havedamaging effects.

Service Response: Section 4(f) of theAct authorizes the Service to developand implement recovery plans for listedspecies, not species that are proposedfor listing. For E. t. extimus, this processtherefore begins with the effective date

of listing. In accordance with section4(f)(B) of the Act the recovery planprocess will address actions necessaryto achieve conservation and recovery ofE. t. extimus, will identify measurablecriteria by which recovery (i.e., thepoint at which protection under the Actis no longer necessary) can be gauged,and will identify the time and costsrequired to achieve recovery. Thespecific issues identified above will beconsidered in developing a recoveryplan, and that plan will be available forpublic review and comment prior toadoption. Monitoring species isfrequently an element of recovery plans,and is also required by section 4(g) ofthe Act for any species deemed to berecovered.

Issue 37: Several commentersquestioned the motivations of thepetitioners in requesting the listing, andothers apparently believed thepetitioners authored the listingproposal. Several commenters notedthat the petition contained inaccuracies,and therefore no listing proposal shouldhave resulted.

Service Response: The Service cannotspeak for the petitioners’ motivations inrequesting listing of E. t. extimus. TheService judged the petition solely on thescientific information it contained.Inaccuracies were found in the petition,but on the whole the Servicedetermined that it presented substantialinformation indicating that listing maybe warranted. The listing proposal wasauthored by the Service, not thepetitioners. The Service developed itsproposal not from the petition, but frominformation gained from journalpublications, agency reports, and thegeneral public’s responses to severalinformation solicitations. This statusreview process had resulted in theService designating E. t. extimus acategory 1 candidate species prior to thepetition being received. Thatdesignation indicated that the Servicehad sufficient information to support alisting proposal but did not publish aproposal immediately because it wasdealing with listing actions of higherpriority. Information presented by thepetitioners that the Service did notalready possess was checked foraccuracy; information that could not beconfirmed, or was found to beinaccurate, was not used.

Issue 38: The Service is required topurchase interest in land or water forimplementation of the Act; this violatesthe U.S. Constitution.

Service Response: Section 5 of the Actdirects the Secretary to use landacquisition and other authorities of theFish and Wildlife Act of 1956, asamended, the Fish and Wildlife

Coordination Act, as amended, and theMigratory Bird Conservation Act, asappropriate. The Secretary isauthorized, but not required, to acquireinterest in land or water to conservethreatened and endangered species. TheService does not carry out theseauthorities in violation of the U.S.Constitution. The Service does notacquire all lands designated as criticalhabitat for a listed species, and does notdevelop critical habitat designationsbased on land ownership or interest oflandowners in purchasing or sellingproperties. It is the Service’s policy toacquire property only on a voluntarybasis from willing sellers.

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

Service Response: Federal actions thattake place outside occupied habitat orcritical habitat, but that may affect E. t.extimus, will be subject to consultationbetween the action agency and theService in accordance with section 7 ofthe Act. Exclusively private actions areunaffected by listing and/or designationof critical habitat, provided they do notresult in violation of section 9 of the Act(e.g., take of the species).

Issue 40: Listing (regardless of criticalhabitat) will have adverse impacts onlocal economy; economic impacts oflisting were not addressed; the Actrequires the Service to consider impactson other wildlife species and social andeconomic impacts prior to listing.

Service Response: Consideration ofeconomic effects is required fordesignation of critical habitat. The Actrequires that species listing decisions bebased solely on the best scientific andcommercial information available,which precludes consideration of socialor cultural impacts or impacts on otherspecies. (See section 4(b)(1)(A) of theAct). The Service anticipates nosignificant impacts on other nativewildlife species as a result of listing,with the probable exception of thebrown-headed cowbird.

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

Service Response: Reports on studiesdone on the Kern River were publishedby Harris et al. (1986), Harris et al.(1987), Whitfield (1990), and Harris(1991). Specific information on projectparticipants, funding sources, andcooperators can be found in thosesources. The Service understands thatmonitoring and cowbird control arebeing continued by the Kern RiverResearch Center and The NatureConservancy, with funding assistancefrom the State of California and theService.


Issue 42: The Service should performadditional surveys before listing.

Service Response: The Service issupporting continuing surveys to detectadditional E. t. extimus, to monitorknown nest sites, and to evaluate habitatpresence, quality, and distribution. TheService supports these surveys withfunding to States in accordance withsection 6 of the Act, and throughlogistical and technical assistance toother agencies and parties. Extensivesurveys in New Mexico and Arizona in1993 located E. t. extimus in numbersthat do not significantly change the totalpopulation estimates made in theproposed rule. These surveys alsoconfirmed high levels of broodparasitism by cowbirds. With lowestimates of total flycatcher numbersbeing validated by continuing surveys,the Service has determined thatsufficient information exists on thethreats of habitat loss and cowbirdparasitism to justify listing.

Issue 43: The Service failed to consultadequately with private interests, State,Federal, and local agencies prior topublishing the proposed rule.

Service Response: The Servicepublished public requests forinformation on the status of E. t. extimusin the Federal Register when it wasdesignated a category 2 candidatespecies in January 1989, and when itwas designated a category 1 species inNovember 1991. The Servicesupplemented these requests withgeneral mailings soliciting information,and information solicitations inprofessional publications. Beyond thesemechanisms, the Service is constrainedby funding limitations and citizens’suits such as Environmental DefenseCenter, Inc. vs. Babbitt et al. IV 93–1848–R (C.D. Calif.), which was broughtto compel the Service to propose listingand designation of critical habitat forthe species, that preclude individuallycontacting every interested party.

Issue 44: The parties who petitionedfor listing should pay for studiessupporting their request.

Service Response: Regulationsimplementing section 4 of the Act,specifically the petition process [50 CFR424.14], do not require petitioners tofund studies supporting their request.Listing determinations are made ifexisting information is deemedsufficient to make a determination. Thisinformation typically originates from avariety of sources.

Issue 45: The southwestern willowflycatcher is abundant. There is no needto list.

Service Response: The Service hasdetermined that E. t. extimus is rare, notabundant, faces serious threats to its

continued existence, and warrantslisting as endangered. See discussionunder Factor A: The present orthreatened destruction, modification, orcurtailment of its habitat or range.

Issue 46: The ‘‘little’’ willowflycatcher (E. t. brewsteri) is the mostcommon subspecies observed andcollected in the Southwest.

Service Response: The abundance ofcollections of E. t. brewsteri from withinthe breeding range of E. t. extimus isbecause E. t. brewsteri migrates throughthe Southwest between its Pacificcoastal breeding range and winteringgrounds in Central America. E. t.brewsteri passes through riparianhabitats in the breeding range of E. t.extimus in spring and fall, but does notbreed there.

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

Service Response: The Service hasdetermined that E. t. extimus isendangered; local areas where the birdis relatively stable could only beexcluded from listing or classified asthreatened if they constituted distinctpopulation segments [50 CFR 424.02(k)].The Service has not identified anydistinct population segments of E. t.extimus. Further, because the Servicedetermines E. t. extimus to beendangered, all existing habitat andlocal nesting concentrations are deemedto be essential to the conservation andrecovery of the species. Protection oflocales where the bird is doingrelatively well may be especiallyimportant for the conservation andrecovery of E. t. extimus.

Issue 48: Prey availability may be alimiting factor.

Service Response: The Servicerecognizes that food availability isalways a potential limiting factor inwildlife populations. It is possible thatreduction of riparian habitats not onlyreduced vegetation for nesting, butreduced or altered the arthropod faunaassociated with surface water andextensive vegetation. Also, as noted inthis rule, some speculation exists thattamarisk provides a substandard nestinghabitat because it supports asignificantly different insect fauna thannative vegetation. However, noinformation was available to evaluatethis factor directly for E. t. extimus.

Issue 49: Several comments werereceived that pertained to the Service’smanagement of the 90-day petitionfinding, including that the 90-daypetition finding was late; that it is notthe Service’s role to conduct a statusreview if information in a petition islacking; and that a 30-day comment

period on the 90-day petition findingwas insufficient.

Service Response: The Serviceacknowledges that its finding on thelisting petition was published after 90days, however, the Act (section4(b)(3)(A) states that the [Service] shall,to the maximum extent practicable,make a petition finding within 90 days(emphasis added). Because the petitionwas found to present substantialinformation indicating that thepetitioned action may have beenwarranted, the Service continued astatus review after this finding, inaccordance with 50 CFR 424.14(b)(3).There are no requirements for theService to open a formal commentperiod regarding a 90-day petitionfinding. The Service did so in this caseto solicit additional information on E. t.extimus. In reaching its 12-monthpetition finding, the Service consideredall information received within the 30-day period identified, and informationreceived for several months thereafter.

Issue 50: E. t. extimus should be listedas threatened, not endangered.

Service Response: The Servicecarefully evaluated the status of E. t.extimus and has determined that itmeets the definition of an endangeredspecies, not a threatened species. Asstated in the proposed rule, (58 FR39495) threatened status would not beappropriate because the large historichabitat loss already has causedextirpation throughout a significantportion of the species’ range. Populationnumbers are extremely low, and avariety of threats are serious andimminent.

Issue 51: Restrictions on rurallivestock grazing will cause ranching tobecome nonviable, and the land will beconverted by suburban development,which is a greater threat to E. t. extimusthan overgrazing.

Service Response: The conversion oflands from livestock grazing to suburbandevelopment is hypothetical andtherefore cannot drive the Service’sdetermination on this issue. Much of thelivestock grazing that may be affected bythis rule takes place on Federal lands.

Therefore, conversion to suburbandevelopment would require landexchanges or sales. These actions, ifthey were determined to affect E. t.extimus, would require consultationunder section 7 of the Act. Regardless,prioritization of threats should beundertaken in the recovery, rather thanlisting, process.

Issue 52: The proposed rule fails toconsider changing ecological factors:drought, migration patterns, nestinghabits, and climatic changes.


Service Response: The Servicerecognizes that populations of E. t.extimus are likely to fluctuate naturallyin response to various ecological factors.However, the Service believes thatdeclines in habitat availability andincreased exposure to cowbirdparasitism have caused populationreductions beyond the scale of naturalfluctuations. Fluctuations in response tononanthropogenic phenomena are likelyto continue, but the current populationlevels are so low that these naturalphenomena may be sufficient to causelocal extirpations.

Issue 53: Restrictions associated withlisting would be in conflict with KernCounty’s General Plan.

Service Response: Under section 4 ofthe Act, the Service considers onlyscientific and commercial informationrelating to the five listing factorsoutlined in section 4(a)(1) and discussedwith respect to E. t. extimus in this rule.Therefore, conflicts with local planswere not considered in making thisdetermination. However, the Servicestrives to pursue conservation andrecovery of listed species in cooperationwith State and local authorities, andseeks to minimize conflicts.

Issue 54: Listing and critical habitatdesignations will adversely affect floodcontrol measures, some authorized bythe Federal Emergency ManagementAgency and other Federal and Stateregulations; the proposed rule failed toconsider flood accommodation needs,channelization, and clearing vegetation.

Service Response: Flood controlmeasures virtually always involve aFederal agency, through funding,permitting, and/or other action.Therefore, flood control measures thatmay affect E. t. extimus would undergoconsultation under section 7 of the Act.Section 7 and its implementingregulations have provisions foremergency consultations, and foractions within presidentially declareddisaster areas.

Issue 55: Government agencies areresponsible for many impacts to riparianareas; campgrounds, fish hatcheries, andsome district offices are located inriparian areas.

Service Response: The Serviceacknowledges that some Federal actionsare in part responsible for the threatsfacing E. t. extimus. As a result oflisting, those Federal actions will besubject to consultation under section 7of the Act to evaluate and minimize theeffects of those actions.

Issue 56: The Service does notacknowledge receipt of comments onlisting, and probably does not readthem.

Service Response: The Service doesnot routinely acknowledge receipt ofeach letter commenting on listingproposals. The number of letters in thiscase made it logistically and financiallyimpossible to acknowledge each one.However, all letters were read, and theirissues addressed either here orelsewhere in this final rule. Allcomment letters and transcripts ofpublic hearings are retained in thepermanent file on this species and areavailable for public inspection.

Issue 57: Protecting flycatcher habitatmay restrict mosquito control, which isimportant for control of encephalitisand other mosquito-borne diseases.

Service Response: Where such controlinvolves a Federal action, mosquito anddisease control actions may be subject toconsultation under section 7(a)(2) of theAct, which would evaluate but notnecessarily restrict or significantlymodify the project. Ultimately, section7(e) of the Act allows exemptions to therequirements of section 7(a)(2).

Summary of Factors Affecting theSpecies

After a thorough review andconsideration of all informationavailable, the Service has determinedthat the southwestern willow flycatchershould be classified as an endangeredspecies. Procedures found at section4(a)(1) of the Act and regulationsimplementing the listing provisions ofthe Act (50 CFR Part 424) werefollowed. A species may be determinedto be an endangered or threatenedspecies due to one or more of the fivefactors described in section 4(a)(1).These factors and their application tothe southwestern willow flycatcher(Empidonax traillii extimus) are asfollows:

A. The Present or ThreatenedDestruction, Modification, orCurtailment of its Habitat or Range

Large scale losses of southwesternwetlands have occurred, particularly thecottonwood-willow riparian habitats ofthe southwestern willow flycatcher(Phillips et al. 1964, Carothers 1977, Rea1983, Johnson and Haight 1984, Katibah1984, Johnson et al. 1987, Unitt 1987,General Accounting Office (GAO) 1988,Bowler 1989, Szaro 1989, Dahl 1990,State of Arizona 1990, Howe and Knopf1991). Changes in riparian plantcommunities have resulted in thereduction, degradation, and eliminationof nesting habitat for the willowflycatcher, curtailing the ranges,distributions, and numbers of westernsubspecies, including E. t. extimus(Gaines 1974, Serena 1982, Cannon andKnopf 1984, Klebenow and Oakleaf

1984, Taylor 1986, Unitt 1987, Schlorff1990, Ehrlich et al. 1992).

Dahl (1990) reviewed estimated lossesof wetlands between 1780 and the1980’s in the Southwest: California isestimated to have lost 91 percent,Nevada 52 percent, Utah 30 percent,Arizona 36 percent, New Mexico 33percent, and Texas 52 percent. As muchas 90 percent of major lowland riparianhabitat has been lost or modified inArizona (State of Arizona 1990).Franzreb (1987) noted that‘‘[B]ottomland riparian forests are themost highly modified of naturallandscapes in California.’’

Loss and modification ofsouthwestern riparian habitats haveoccurred from urban and agriculturaldevelopment, water diversion andimpoundment, channelization, livestockgrazing, off-road vehicle and otherrecreational uses, and hydrologicalchanges resulting from these and otherland uses. Rosenberg et al. (1991) notedthat ‘‘it is the cottonwood-willow plantcommunity that has declined most withmodern river management.’’ Loss of thecottonwood-willow riparian forests hashad widespread impact on thedistribution and abundance of birdspecies associated with that forest type(Hunter et al. 1987, Hunter et al. 1988,Rosenberg et al. 1991).

Overuse by livestock has been a majorfactor in the degradation andmodification of riparian habitats in thewestern United States. These effectsinclude changes in plant communitystructure and species composition, andrelative abundance of species and plantdensity. These changes are often linkedto more widespread changes inwatershed hydrology (Rea 1983, GeneralAccounting Office 1988) and directlyaffect the habitat characteristics criticalto E. t. extimus. Livestock grazing inriparian habitats typically results inreduction of plant species diversity anddensity, especially of palatablebroadleaf plants like willows andcottonwood saplings, and is one of themost common causes of ripariandegradation (Carothers 1977, USDAForest Service 1979, Rickard andCushing 1982, Cannon and Knopf 1984,Klebenow and Oakleaf 1984, GAO 1988,Clary and Webster 1989, Schultz andLeininger 1990).

Increases in abundance of riparianbird species have followed reduction,modification, or removal of cattlegrazing. Krueper (1993) found thefollowing increases in birds associatedwith cottonwood-willow habitat onArizona’s San Pedro River four yearsafter the removal of livestock: yellowwarbler, 606 percent; common yellow-throat, 2,128 percent; yellow-breasted


chat, 423 percent. Bock et al. (1993)found that 40 percent of the riparianbird species they examined, includingthe willow flycatcher (varioussubspecies), were negatively affected bylivestock grazing. Increases in willowflycatcher numbers (various subspecies)have followed reduction, modification,or removal of cattle grazing. Taylor(1986) found a negative correlationbetween recent cattle grazing andabundance of numerous riparian birds,including the Great Basin willowflycatcher (E. t. adastus). In an areaungrazed since 1940, his bird countswere five to seven times higher thancomparable plots where grazing wasterminated in 1980. Taylor andLittlefield (1986) found higher numbersof Great Basin willow flycatcherscorrelated with minimal or nonexistentlivestock grazing. Klebenow and Oakleaf(1984) listed the Great Basin willowflycatcher among bird species thatdeclined from abundant to absent inriparian habitats degraded in part byovergrazing. Schlorff reported willowflycatchers returning to Modoc County,California, several years after removal oflivestock grazing (pers. comm. cited inValentine et al. 1988). Knopf et al.(1988) found that, during the summer,Great Basin willow flycatchers werepresent on winter-grazed pastures, butwere virtually absent from summer-grazed pastures.

The Service believes thatdocumentation of livestock impacts onother willow flycatcher subspecies isrelevant to E. t. extimus, because linearriparian habitats in the arid range of E.t. extimus are especially vulnerable tofragmentation and destruction bylivestock. As shady, cool, wet areasproviding abundant forage, they aredisproportionately preferred bylivestock over the surrounding xericuplands (Ames 1977, Valentine et al.1988, A. Johnson 1989). Harris et al.(1987) believed that termination ofgrazing along portions of the South Forkof the Kern River in California wasresponsible for increases in riparianvegetation and, consequently, nesting E.t. extimus. Suckling et al. (1992) notedthat most of the areas still known tosupport E. t. extimus have low ornonexistent levels of livestock grazing.More recent surveys (Muiznieks et al.1994) have found E. t. extimus in areaswith livestock grazing; however, theseoccur in widely dispersed, small groupswhose nesting success is largelyunknown, and where livestock grazingintensity and seasonality are alsounknown.

Another likely factor in the loss andmodification of southwestern willowflycatcher habitat is invasion by the

exotic tamarisk. Tamarisk (also calledsaltcedar) was introduced into westernNorth America from the Middle East inthe late 1800’s as an ornamentalwindbreak and for erosion control. Ithas spread rapidly along southwesternwatercourses, typically at the expense ofnative riparian vegetation, especiallycottonwood/willow communities.Although tamarisk is present in nearlyevery southwestern ripariancommunity, its dominance varies. It hasreplaced some communities entirely,but occurs at a low frequency in others.

The spread and persistence oftamarisk has resulted in significantchanges in riparian plant communities.In monotypic tamarisk stands, the moststriking change is the loss of communitystructure. The multilayered communityof herbaceous understory, small shrubs,middle-layer willows, and overstorydeciduous trees is often replaced by onemonotonous layer. Plant speciesdiversity has declined in many areas,and relative species abundance hasshifted in others. Other effects includechanges in percent cover, total biomass,fire cycles, thermal regimes, andperhaps insect fauna (Kerpez and Smith1987, Carothers and Brown 1991,Rosenberg et al. 1991, Busch and Smith1993).

Disturbance regimes imposed by man(e.g., grazing, water diversion, floodcontrol, woodcutting, and vegetationclearing) have facilitated the spread oftamarisk (Behle and Higgins 1959,Kerpez and Smith 1987, Hunter et al.1988, Rosenberg et al. 1991). Cattle findtamarisk unpalatable. However, they eatthe shoots and seedlings of cottonwoodand willow, acting as a selective agentto shift the relative abundance of thesespecies (Kerpez and Smith 1987).Degradation and, in some cases, loss ofnative riparian vegetation lowered thewater table and resulted in the loss ofperennial flows in some streams. Withits deep root system and adaptivereproductive strategy, tamarisk thrivesor persists where surface flow has beenreduced or lost. Further, tamariskestablishment often results in a self-perpetuating regime of periodic fires,which were uncommon in nativeriparian woodlands (Busch and Smith1993).

Manipulation of perennial rivers andstreams has resulted in habitats thattend to allow tamarisk to outcompetenative vegetation. Construction of damscreated impoundments that destroyednative riparian communities. Dams alsoeliminated or changed flood regimes,which were essential in maintainingnative riparian ecosystems. Changing(usually eliminating) flood regimesprovided a competitive edge to

tamarisk. In contrast to nativephreatophytes, tamarisk does not needfloods and is intolerant of submersionwhen young. Diversion of water causedthe lowering of near-surfacegroundwater and reduced the relativesuccess of native species in becomingestablished. Irrigation water containinghigh levels of dissolved salts also favorstamarisk, which is more tolerant of highsalt levels than most native species(Kerpez and Smith 1987, Busch andSmith 1993).

The rapid spread of tamarisk hascoincided with the decline of thesouthwestern willow flycatcher.Although E. t. extimus has beendocumented nesting in tamarisk, it isnot known whether, over the long term,reproductive success of southwesternwillow flycatchers nesting in tamariskhas differed from the success offlycatchers nesting in native vegetation.Studies in Arizona have documentedlow breeding densities and lowreproductive success for southwesternwillow flycatchers nesting in tamarisk(Hunter et al. 1988, Muiznieks et al.1994). These data, coupled with apossible decrease in the arthropod preybase and thermal protection for nestsprovided by tamarisk, suggest thattamarisk may provide poor qualitynesting habitat. However, moreextensive comparative studies areneeded to determine the overall impacton the southwestern willow flycatcherof the conversion of native broadleaf-dominated riparian habitat to tamarisk-dominated habitat.

Other studies of riparian birdcommunities have documented changesin bird species diversity, correspondingwith invasion by tamarisk.

Conversion to tamarisk typicallycoincides with reduction or completeloss of bird species strongly associatedwith cottonwood-willow habitats. Theseinclude the yellow-billed cuckoo(Coccyzus americanus), summer tanager(Piranga rubra), northern oriole (Icterusgalbula), and the southwestern willowflycatcher (Hunter et al. 1987, Hunter etal. 1988, Rosenberg et al. 1991). WhileBrown and Trosset (1989) believedtamarisk may serve as an ‘‘ecologicalequivalent’’ to native vegetation, theynoted that their study occurred where atamarisk community became establishedwhere no native equivalent existedbefore.

Some authors believe tamarisk maynot provide the thermal protection thatnative broadleaf species do (Hunter etal. 1987, Hunter et al. 1988). This couldbe important at lower elevations in theSouthwest, where extreme hightemperatures are common during thebird’s midsummer breeding season. It is


also possible that tamarisk affects E. t.extimus by altering the riparian insectfauna (Carothers and Brown 1991).Some sources also speculated that nestsin tamarisk stands may be more easilylocated by brown-headed cowbirds (seecowbird discussion below). Hunter et al.(1987) reported the willow flycatcher asone of seven midsummer-breedingbuilders of open nests that were foundin tamarisk at higher elevations but notlower elevations. Nesting E. t. extimushave been found in tamarisk at middleelevations (610–1200 m (2000–3500feet)) (Hundertmark 1978, Hubbard1987, Hunter et al. 1987, Brown 1988,Sogge et al. 1993, Muiznieks et al.1994). However, nest success intamarisk at these elevations appears tobe low (Sogge and Tibbitts 1992, Soggeet al. 1993, Muiznieks et al. 1994). Thespecies is essentially absent fromtamarisk-dominated habitats below 610m (2000 feet). On the lower ColoradoRiver (approximately 25 m (80 feet))where tamarisk is widely dominant, theonly territories found in recent decadeswere in relict stands dominated bywillow, cottonwood, and other nativevegetation (Muiznieks et al. 1994). Unitt(1987) speculated that at higherelevations and in the eastern portion ofits range, some E. t. extimus populationsmay be adapting to tamarisk.

Water developments also likelyreduced and modified southwesternwillow flycatcher habitat. The series ofdams along most major southwesternrivers (Colorado, Gila, Salt, Verde, RioGrande, Kern, San Diegito, and Mojave)have altered riparian habitatsdownstream of dams throughhydrological changes, vegetationalchanges, and inundated habitatsupstream. New habitat is sometimescreated along the shoreline of reservoirs,but this habitat (often tamarisk) is oftenunstable because of fluctuating levels ofregulated reservoirs (Grinnell 1914,Phillips et al. 1964, Rosenberg et al.1991). Construction of Glen CanyonDam on the Colorado River allowedestablishment of a tamarisk ripariancommunity downstream in the GrandCanyon, where a small population of E.t. extimus exists, with poorreproduction (Brown 1991, Sogge et al.1993). However, Lake Powell, formedupstream of the dam, inundated whatwas apparently superior habitat, with E.t. extimus considered common (Behleand Higgins 1959).

Diversion and channelization ofnatural watercourses are also likely tohave reduced E. t. extimus habitat.Diversion results in diminished surfaceflows and increased salinity of residualflows. Consequent reductions andcomposition changes in riparian

vegetation are likely. Channelizationoften alters stream banks and fluvialdynamics necessary to maintain nativeriparian vegetation.

Suckling et al. (1992) suggested thatlogging in the upper watersheds ofsouthwestern rivers may constituteanother potential threat to thesouthwestern willow flycatcher. Theystated that logging increases thelikelihood of damaging floods insouthwestern willow flycatcher nestinghabitat.

Finally, the willow flycatcher (allsubspecies) is listed among neotropicalmigratory birds that may be impacted byalteration of wintering habitat, asthrough tropical deforestation (Finch1991, Sherry and Holmes 1993).

Population Trends for Each State AreDiscussed Briefly Below

California. All three residentsubspecies of the willow flycatcher (E.t. extimus, E. t. brewsteri, and E. t.adastus) were once considered widelydistributed and common in California,wherever suitable habitat existed(Wheelock 1912, Willett 1912, Grinnelland Miller 1944). The historic range ofE. t. extimus in California apparentlyincluded all lowland riparian areas ofthe southern third of the State. Unitt(1984, 1987) concluded that it was oncefairly common in the Los Angeles basin,the San Bernardino/Riverside area, andSan Diego County. Willett (1912, 1933)considered the bird to be a commonbreeder in coastal southern California.Nest and egg collections indicate thebird was a common breeder along thelower Colorado River near Yuma in1902 (T. Huels, University of Arizona inlitt., transcripts of H. Brown’s fieldnotes).

All three willow flycatcher subspeciesbreeding in California have declined,with declines most critical in E. t.extimus, which remains only in small,disjunct nesting groups (Unitt 1984 and1987, Gaines 1988, Schlorff 1990,Service unpubl. data). Only two nestinggroups have been stable or increasing inrecent years. One is on private landwhere habitat impacts from livestockgrazing have been virtually eliminated(Harris et al. 1987, Whitfield 1990). Thisgroup on the South Fork of the KernRiver experienced numerical declines in1991 and 1992, but increases in nestingsuccess were realized in 1992 and 1993,attributed to shaking (killing) orremoving cowbird eggs or nestlingsfound in flycatcher nests, and trappingcowbirds (Whitfield and Laymon, KernRiver Research Center, in litt. 1993). Theother apparently stable nesting group isalong the Santa Margarita River onMarine Corps Base Camp Pendleton,

where cowbird numbers have also beenreduced by trapping (Griffith andGriffith 1993). Approximately eightother nesting groups are known insouthern California, all of whichconsisted of six or fewer nesting pairs inrecent years (Unitt 1987, Schlorff 1990,Service, unpubl. data). Using the mostrecent information for all areas,approximately 70 pairs and 8 singlesouthwestern willow flycatchers areknown to exist in California. Whereinformation on population trends sincethe mid-1980’s is available, most areasshow declines. Three recent statusreviews considered extirpation fromCalifornia to be possible, even likely, inthe foreseeable future (Garrett and Dunn1981, Harris et al. 1986, Schlorff 1990).The State of California classifies thewillow flycatcher as endangered[California Department of Fish andGame (CDFG) 1992].

Arizona. Records indicate that theformer range of the southwestern willowflycatcher in Arizona included portionsof all major watersheds (Colorado, Salt,Verde, Gila, Santa Cruz, and San Pedro).Historical records exist from theColorado River near Lee’s Ferry andnear the Little Colorado Riverconfluence (Phillips, pers. comm., citedin Unitt 1987), and along the Arizona-California border (Phillips 1948, Unitt1987), the Santa Cruz River near Tucson(Swarth 1914, Phillips 1948), the VerdeRiver at Camp Verde (Phillips 1948), theGila River at Fort Thomas (W.C. Hunter,pers. comm., cited in Unitt 1987), theWhite River at Whiteriver, the upperand lower San Pedro River (Willard1912, Phillips 1948), and the LittleColorado River headwaters area(Phillips 1948).

The southwestern willow flycatcherhas declined throughout Arizona. Thesubspecies was apparently abundant onthe lower Colorado River in 1902 (T.Huels in litt., transcripts of H. Brown’sfield notes), but only four to fiveterritories were located in 1993(Muiznieks et al. 1994). Elsewhere inthe State, E. t. extimus persists only inseveral small, widely scatteredlocations. In the Grand Canyon, severalgroups of nesting birds have fluctuatedfrom a high of 11 singing males in 1986(Brown 1988) to two pairs and threesingle birds in 1992 (Sogge and Tibbitts1992). Grand Canyon surveys in 1993located 13 birds; six unpairedindividuals, two pairs, and whatappeared to be one male with twofemales. No nesting attempts weresuccessful (Sogge et al. 1993). AlthoughBrown (et al. 1987) noted E. t. extimusas nesting in Havasu Canyon, in 1993none were located there and cowbirdswere abundant (Sogge et al. 1993). A


location on the lower San Pedro Riverapparently supported relatively largenumbers of E. t. extimus in the 1940’s(G. Monson, private individual, in litt.1993 and pers. comm. 1993), but only asingle pair in 1978 and 1979, and nonein 1986 (Unitt 1987). Following habitatimprovements at this locale, six to sevensinging males were present in 1993, anda total of 11 singing males were locatedat two other locations on the lower SanPedro in 1993 (Muiznieks et al. 1994).

Historically occupied habitat on theupper San Pedro River is in the processof rehabilitation, but remainsunoccupied by nesting E. t. extimus(Krueper and Corman 1988, D. Krueperunpubl. data). Two small groups at highelevations in the White Mountains,comprising approximately five singingmales each, have remained relativelystable numerically from 1985 to 1993(Muiznieks et al. 1994, Arizona Gameand Fish Department (AGFD), unpubl.data). At a site on the Verde River incentral Arizona where R. Ohmart(unpubl. data) observed four nestingpairs in 1992, one pair and one singlemale were present in 1993. The singlenest produced only a cowbird young. Of13 river reaches in Arizona studied byHunter et al. (1987), nesting E. t.extimus were extirpated from eight,declining in two, and present in stablenumbers in three.

Statewide surveys in 1993 locatedbetween 42 and 56 territorial males, andall nest sites were considered vulnerableto habitat loss and cowbird parasitism(Muiznieks et al. 1994). Preliminarydata from 1994 surveys indicate thatapproximately 70 to 80 breeding pairswere found at a total of 12 locations inthe State. This included the discovery ofa group of flycatchers at one locationconsisting of approximately 15 breedingpairs. Brood parasitism by cowbirds wasdocumented at at least six (50%) ofthose 12 sites. Brown-headed cowbirdswere documented at all 12 breedinglocations (Arizona Game and FishDepartment, in prep.).

Where information on populationtrends since the mid-1980’s is available,most areas show declines and/or highrates of cowbird parasitism. In early1993, catastrophic flooding on theVerde, Gila, and San Pedro Riverstemporarily damaged many sitesinhabited since the mid-1980’s, andmuch potential habitat. Unitt (1987)concluded that ‘‘Probably the steepestdecline in the population levels of E. t.extimus has occurred in Arizona * * *E. t. extimus has been extirpated frommuch of the area from which it wasoriginally described, the riparianwoodlands of southern Arizona.’’ The

State of Arizona classifies the willowflycatcher as endangered (AGFD 1988).

New Mexico. Bailey (1928) classifiedbreeding willow flycatchers in NewMexico as E. t. brewsteri, according toOberholser’s (1918) taxonomy of thattime. Because of few records at thattime, she believed that either the birdwas rare or was overlooked by mostobservers and collectors. More recently,Hubbard (1987) reviewed andsummarized the flycatcher’s status inNew Mexico. He classified breedingbirds in the State as E. t. extimus andreported breeding locations that weregenerally confined to the regions west ofthe Rio Grande, with records from theRio Grande, Chama, Zuni, SanFrancisco, and Gila drainages (See alsoHubbard 1982). However, heprovisionally assigned all willowflycatchers nesting in New Mexico to E.t. extimus, noting records from thePecos River and Penasco Creek in thesoutheast and from near Las Vegas inthe northeast.

Both Hubbard (1987) and Unitt (1987)believed that the overall range of E. t.extimus had not been reduced in NewMexico, but that habitat and numbershad declined. Unitt (1987) believed themajority of all remaining nesting birdsmay occur in New Mexico. Areas with19 and 53 singing flycatchers, notdistinguished as nesting or migrants,were found on the upper Gila River(Montgomery et al. 1985, cited inSuckling et al. 1992). Preliminary datafrom 1994 surveys indicate that thisbreeding group is still present. However,the breeding status of flycatchers andtrend over time have not beendetermined (S.O. Williams, New MexicoDepartment of Game and Fish—pers.comm.)

Hubbard (1987) noted that data werelacking for trends of most nesting areas.However, where data were available,they indicated loss of a group of 15breeding pairs by the rising waters ofElephant Butte Reservoir. The willowflycatcher was considered fairlycommon in this area on the middle RioGrande in the late 1970’s (Hundertmark1978). Hubbard hypothesized that someof these birds could have movedupstream, to new shoreline habitatcreated by the impoundment. Between1987 and 1990, bird surveys along theRio Grande Valley State Park inAlbuquerque found a single singingwillow flycatcher during the breedingseason (Hoffman 1990). Current trendsin New Mexico are not beingextensively monitored. However, in1992, 71 transects along the Rio Grandewere surveyed for breeding birds, butnot specifically targeting willowflycatcher habitat. A single willow

flycatcher was located near Espanola(Leal, Meyer and Thompson, unpubl.data). In 1993, surveys of 52 locationsfound 31 pairs or singing males at 15 ofthose locations (S.O. Williams III, NewMexico Department of Game and Fish(NMDGF), in litt. 1993). Hubbard (1987)estimated that the State population maytotal 100 pairs; that estimate has notbeen revised. Hubbard (1987) found that‘‘the conclusion is virtually inescapable* * * a decrease has occurred in thepopulation of breeding willowflycatchers in New Mexico over historictime,’’ resulting from habitat loss. TheState of New Mexico classifies thewillow flycatcher as endangered(NMDGF 1988).

Texas. The eastern limit of thesouthwestern willow flycatcher’sbreeding range is in western Texas(Unitt 1987). Collections have beenmade at Fort Hancock on the Rio Grande(Phillips 1948), in the GuadalupeMountains (Phillips, pers. comm., citedin Unitt 1987), the Davis Mountains(Oberholser 1974), and from unspecifiedlocales in Brewster County (Wolfe1956). Wauer (1973 and 1985)considered E. t. extimus a rare summerresident in Big Bend National Park. Dataare lacking on current population levelsand trends in Texas. Loss andmodification of habitat may havereduced populations on the Rio Grandeand Pecos Rivers.

Utah. The north-central limit ofbreeding southwestern willowflycatchers is in southern Utah. Behle(1985) and Unitt (1987) believed a clinalgradation between E. t. extimus and E.t. adastus existed, but Browning (1993)disagreed, identifying a range boundaryat approximately the 38th north parallel.Southern Utah is characterized byextreme topographic relief. In thisregion, subspecific separation may be afunction of elevation, with E. t. extimusat lower elevations (e.g., Virgin andColorado Rivers) and E. t. adastushigher (e.g., Sevier River, wet meadowsof 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, andalong the San Juan and Colorado Rivers(Behle et al. 1958, cited in Unitt 1987;Behle and Higgins 1959, Behle 1985; seealso Browning 1993). Other reportsdocument the subspecies being presentalong the Virgin, Colorado, San Juan,and perhaps Paria Rivers (BLM, unpubl.data). Although Behle believed E. t.extimus was always rare in southernUtah overall (pers. comm. cited in Unitt1987), he considered it a locallycommon breeding resident wherehabitat existed along the Colorado River


and its tributaries in southeastern Utah(Behle and Higgins 1959).

Few data are available on populationtrends in southern Utah. However, lossand modification of habitat is likely tohave reduced populations on the Virgin,Colorado, and San Juan Rivers. Theselosses have been due to suburbanexpansion and habitat changes along theVirgin River, inundation by Lake Powellon the Colorado and San Juan Rivers,and encroachment of tamariskthroughout the region (Unitt 1987, BLMunpublished data).

Nevada. Unitt (1987) reported onlythree records for Nevada, all madebefore 1962. Unitt (1987), Hubbard(1987), and Browning (1993) allconsidered southern Nevada(approximately south of 38° northparallel) to be within the range of E. t.extimus. However, no recent data areavailable on population levels or trends.Habitat may remain along the lowerVirgin River and at the inflow of theVirgin River into Lake Mead. However,loss and modification of habitat is likelyto have reduced populations on theVirgin and Colorado Rivers.

Colorado. Whether or not thesouthwestern willow flycatcher breedsin Colorado is unclear. Hubbard (1987)believed the subspecies ranged intoextreme southwestern Colorado,Browning (1993) was noncommittal,and Unitt (1987) tentatively used theNew Mexico-Colorado border as theboundary between E. t. extimus and E.t. adastus. Several specimens taken inlate summer have been identified as E.t. extimus, but nesting was notconfirmed (Bailey and Niedrach 1965).Phillips (1948) cautioned that willowflycatchers in this region displayedconsiderable individual variation andmay represent intergrades between E. t.extimus and E. t. adastus. No recentdata are available on occurrence,population levels, or trends in this area.

Mexico. Six specimens from BajaCalifornia del Norte and two fromSonora were discussed by Unitt (1987).He and Phillips (pers. comm., cited inUnitt 1987) believed E. t. extimus wasnot common in northwestern Mexico.Wilbur (1987) was skeptical of itspresence as a breeder in Baja California.In the more general treatments of fieldguides, the willow flycatcher isdescribed as breeding in extremenorthwestern Mexico, includingnorthern Baja California del Norte(Blake 1953, Peterson 1973). No recentdata are available on current populationlevels or trends.

Using the most recent censuses andestimates for all areas, the estimatedtotal of all southwestern willowflycatchers is approximately 300 to 500

nesting pairs. Unitt (1987) believed thetotal was ‘‘well under’’ 1000 pairs, morelikely 500. The regional estimates andinformation on which these totalestimates are based generally date fromthe late 1980’s to 1993 (e.g., Hubbard1987, T. Johnson 1989). Virtually allnesting groups monitored since thattime have continued to decline(Whitfield 1990, Brown 1991, Sogge etal. 1993, Whitfield and Laymon,unpubl. data).

B. Overutilization for Commercial,Recreational, Scientific, or EducationalPurposes

The Service is unaware of threatsresulting from overutilization.

C. Disease or PredationThe Service is unaware of any disease

that constitutes a significant threat to E.t. extimus. Boland et al. (1989) foundonly one case of larval parasites inwillow flycatcher nestlings inCalifornia.

Predation of southwestern willowflycatchers may constitute a significantthreat and may be increasing withhabitat fragmentation. Where E. t.extimus has been extirpated in the lowerColorado River valley, Rosenberg et al.(1991) found increases in the great-tailed grackle (Quiscalus mexicanus),which preys on the eggs and young ofother birds (Bent 1965). Whitfield (1990)found predation on E. t. extimus neststo be significant. Predation increasedwith decreasing distance from nests tothicket edges, suggesting that habitatfragmentation may increase the threat ofpredation.

D. The Inadequacy of ExistingRegulatory Mechanisms

The Migratory Bird Treaty Act(MBTA)(16 U.S.C. § 703–712) is the onlycurrent Federal protection provided forthe southwestern willow flycatcher. TheMBTA prohibits ‘‘take’’ of any migratorybird, which is defined as: ‘‘* * * topursue, hunt, shoot, wound, kill, trap,capture, or collect, or attempt to pursue,hunt, shoot, wound, kill, trap, capture,or collect * * *’’ However, unlike theAct, there are no provisions in theMBTA preventing habitat destructionunless direct mortality or destruction ofactive nests occurs.

The majority of the southwesternwillow flycatcher’s range lies withinCalifornia, Arizona, and New Mexico(Phillips 1948, Hubbard 1987, Unitt1987). All of those States classify thewillow flycatcher as endangered (AGFD1988, NMDGF 1988, CDFG 1992). TheState listings in New Mexico andArizona do not convey habitatprotection or protection of individuals

beyond existing regulations on capture,handling, transportation, and take ofnative wildlife. The CaliforniaEndangered Species Act (CESA)prohibits unpermitted possession,purchase, sale, or take of listed species.However, the CESA definition of takedoes not include harm, which under theAct can include destruction of habitatthat actually kills or injures wildlife bysignificantly impairing essentialbehavioral patterns (50 CFR 17.3).However, CESA requires consultationbetween the CDFG and other Stateagencies to ensure that activities of Stateagencies will not jeopardize thecontinued existence of State-listedspecies (E. Toffoli, State of California, inlitt. 1992). The Service believes that thisand other regulatory mechanisms areinadequate to ensure the continuedexistence of the southwestern willowflycatcher.

E. Other Natural or Manmade FactorsAffecting Its Continued Existence

The riparian habitat of thesouthwestern willow flycatcher hasalways been rare and has become moreso. Its habitat rarity and small, isolatedpopulations make the remaining E. t.extimus increasingly susceptible to localextirpation through stochastic eventssuch as floods, fire, brood parasitism,predation, depredation, and landdevelopment. In early 1993,catastrophic floods in southernCalifornia and Arizona impacted muchof the remaining occupied or potentialbreeding habitat. Historically, thesefloods have always destroyed habitatbut were also important events inregenerating cottonwood-willowcommunities. However, with littlesouthwestern willow flycatcher habitatremaining, widespread events like thoseof 1993 could destroy virtually allremaining habitat throughout all or asignificant portion of the subspecies’range. Further, regeneration withnatural vegetation after floods may beinhibited if the area is subjected toovergrazing by domestic livestock.

The disjunct nature of habitats andsmall breeding populations impede theflow of genetic material and reduce thechance of demographic rescue frommigration from adjacent populations.The resulting constraints on the genepool intensify the external threats to thespecies.

Brood parasitism by the brown-headed cowbird also threatens thesouthwestern willow flycatcher.Cowbirds lay their eggs in the nests ofother, usually smaller, songbirds. Thecowbird often removes a number of thehost’s eggs and replaces them with anequal number of cowbird eggs. The host


species then incubates the cowbird eggs,which typically hatch prior to the host’sown eggs. Cowbird eggs require arelatively short incubation period of 10to 12 days. Thus, the young cowbirdshave several advantages over the host’syoung; they hatch earlier, they arelarger, and they are also more aggressivethan the host’s young. Cowbirdnestlings typically outcompete those ofthe host species for parental care, and,as a result, the host species’ ownreproduction is reduced or eliminated(Bent 1965, McGeen 1972, Mayfield1977a, Harrison 1979, Brittingham andTemple 1983).

The brown-headed cowbirdcommonly preys on insects stirred upby grazing ungulates, and was originallyrestricted to the Great Plains, where itwas strongly associated with Americanbison (Bison bison). As North Americawas settled, cowbirds became associatedwith livestock and human agriculturebecause of the food sources theyprovided (Bent 1965, Flett and Sanders1987, Valentine et al. 1988). Theexpansion of agriculture, livestockgrazing, and wide scale human activitiesin general caused opening andfragmenting of forest and woodlandhabitats. Habitat fragmentation andagriculture are strongly correlated withincreased rates of brood parasitism bybrown-headed cowbirds (Rothstein et al.1980, Brittingham and Temple 1983,Airola 1986, Robinson et al. 1993).Some species are likely to have adaptedto parasitism over time, particularlyprairie nesters in the original range ofthe cowbird. However, the cowbird’srapid expansion now brings it intocontact with forest and woodlandspecies not adapted to deal with broodparasitism, significantly impacting thosespecies (Hill 1976, Mayfield 1977a,Robinson et al. 1993).

The brown-headed cowbird wasapparently an uncommon bird withinthe range of E. t. extimus, until the late1800’s. Since then, the species hasgreatly expanded in numbers anddistribution throughout the region(Laymon 1987, Rothstein in prep.).Increases in cowbirds in the SanBernardino Valley between 1918 and1928 caused Hanna (1928)‘‘considerable alarm.’’ AlthoughFriedmann et al. (1977) reportedrelatively low rates of parasitism ofwillow flycatchers in the westernUnited States, this was apparentlyowing to their data (egg sets) beingcollected prior to the major incursionsof cowbirds into Pacific coast riparianhabitats (L. Kiff, Western Foundation forVertebrate Zoology, in litt. 1993). Broodparasitism of several subspecies of thewillow flycatcher, including E. t.

extimus, by brown-headed cowbirds iswell documented (Hanna 1928, Rowley1930, Willett 1933, Hicks 1934, King1954, Holcomb 1972, Friedmann et al.1977, Garret and Dunn 1981, Harris etal. 1987, Brown 1988, 1991, Sedgewickand Knopf 1988, Whitfield 1990, Harris1991, Sogge et al. 1993, Muiznieks et al.1994).

The increases in cowbirds in theSouthwest and parasitism of E. t.extimus and other birds are generallyattributed to the following scenario: Theintroduction of modern humansettlements, livestock grazing, and otheragricultural developments resulted inhabitat fragmentation. Simultaneously,livestock grazing and other agriculturaldevelopments served as vectors forcowbirds by providing feeding areasnear host species’ nesting habitats(Hanna 1928, Gaines 1974, Mayfield1977a). Cowbirds may travel almost 7kilometers (4.2 miles) from feeding siteswhere livestock congregate to areaswhere host species are parasitized(Rothstein et al. 1984). These factorsincreased both the vulnerability of E. t.extimus and the likelihood ofencounters with cowbirds. Finally, thehigh edge-to-interior ratio of linearriparian habitats like those used by E. t.extimus renders birds nesting thereparticularly vulnerable to parasitism(Airola 1986, Laymon 1987, Harris1991). Linear riparian habitats are alsoespecially vulnerable to fragmentationby grazing, which further increases boththe edge-to-interior ratio and the threatof parasitism.

The effects of parasitism by brown-headed cowbirds on willow flycatchersinclude reducing nest success rate andegg-to-fledging rate, and delayingsuccessful fledging (because of renestingattempts) (Harris 1991). A commonresponse to parasitism is abandonmentof the nest (Holcomb 1972). Willowflycatchers may also respond toparasitism by ejecting cowbird eggs, byburying them with nesting material andrenesting on top of them, or by renestingin another nest (Harris et al. 1991).However, the success rate of renesting isoften reduced, because these attemptsproduce fledglings several weeks laterthan normal, which may not allow themadequate time to prepare for migration(Harris 1991). Renesting also usuallyconsists of smaller clutches, furtherreducing overall reproductive potential(Holcomb 1974).

McCabe (1991) downplayed thesignificance of cowbird parasitism as athreat to any species except Kirtland’swarbler (Dendroica kirtlandii).McCabe’s monograph focussed on thecombined ‘‘Traill’s flycatcher’’superspecies, comprised of E. t. traillii

and E. alnorum in marshy habitats inthe upper Midwest, where parasitismrates ranged from 3 percent to 19percent. However, perhaps reflecting hisregional perspective, he characterizedthe high parasitism rates on willowflycatchers reported by Trautman (1940,cited in McCabe 1991) and Sedgwickand Knopf (1988) as aberrant (56percent and 41 percent, respectively).McCabe considered the high rates theresult of the ‘‘* * * linear configurationof the habitat * * * [c]owbirds lay eggsin songbird nests closest to cover edge.’’The vast majority of southwesternwillow flycatcher habitat is very linearand may experience higher rates ofparasitism than other willow flycatchersubspecies.

Brittingham and Temple (1983)considered ‘‘high’’ parasitism rates(percent of nests parasitized) to be 24percent, with some as high as 72percent. Mayfield (1977a) thought aspecies (or population) might be able tosurvive a 24 percent parasitism rate, butthat losses much higher than that‘‘would be alarming.’’ Parasitism rates of72 percent to 83 percent on Kirtland’swarbler (Mayfield 1977b) resulted in aprecipitous population decline. Whereparasitism rates are known for E. t.extimus, they are comparable to rates forKirtland’s warbler and are capable ofcausing similar declines. In California,parasitism rates ranged from 50 percentto 80 percent between 1987 and 1992,when an estimated population sizedecreased from 44 to 28 nesting pairs(Whitfield 1990, Harris et al. 1991,Whitfield and Laymon, unpubl. data).These parasitism rates were consideredminimum measures, because severalnests were abandoned each year due tounknown causes, which could havebeen parasitism. Brown (1988) reportedan average 50 percent parasitism rate inthe Grand Canyon between 1982 and1987. Although his estimatedpopulation increased from two pairs to11 during that period, it has sincedecreased back as low as two nestingpairs (Brown 1991, Sogge and Tibbitts1992). In 1993, parasitism reached 100percent in the Grand Canyon, and no E.t. extimus were fledged (Sogge et al.1993). Harris et al. (1991) believed thatthe parasitism rates observed on theKern River in 1987 (68 percent of allnests, 88 percent of all nest territories)were high enough to prevent E. t.extimus from recolonizing lowlandriparian habitat, even if it were restored.

Rothstein et al. (1980), Stafford andValentine (1985), and Harris (1991)believed parasitism may be correlatedwith elevation, being more severe atlower elevations. Coupled with greaterloss of lowland (desert) riparian habitat,


the effects of habitat loss and parasitismare compounded. However, cowbirdsnow appear to be increasing at higherelevations (Hanka 1985).

In addition to causing habitatdegradation and facilitating broodparasitism, livestock grazing in and nearriparian areas may also threaten E. t.extimus through direct mortality.Livestock in riparian habitats sometimesmake physical contact with nests orsupporting branches, resulting indestruction of nests and spillage of eggsor nestlings. All known documentationof this threat involves E. t. brewsteri,perhaps because virtually all knownremaining populations of E. t. extimusare in ungrazed habitats (Serena 1982,Harris et al. 1987, Whitfield andLaymon, unpubl. data). Valentine et al.(1988) studied willow flycatchers inCalifornia from 1983 through 1987,when 11 of their 20 recorded nestingattempts failed. They found that ‘‘Priorto reduction of grazing intensity in1987, livestock accounted for 36 percentof the failed nests or 20 percent of allnesting attempts. In addition, livestockdestroyed four successful nests shortlyafter the young had fledged.’’ Staffordand Valentine (1985) reported that threeof eight (37.5 percent) willow flycatchernests in their study site were probablydestroyed by cattle. Flett and Sanders(1987) documented no nest upsets dueto livestock but noted the vulnerabilityof nests to upset, due to their placementlow in willow clumps (see also Serena1982). Livestock grazing may affect E. t.extimus similarly.

The southwestern willow flycatcher’spreference for, and former abundancein, floodplain areas that are now largelyagricultural may indicate a potentialthreat from pesticides. Where flycatcherpopulations remain, they are sometimesin proximity to agricultural areas, withthe associated pesticides and herbicides.Without appropriate precautions, theseagents may potentially affect thesouthwestern willow flycatcher throughdirect toxicity or effects on their insectfood base. No quantitative data on thispotential threat are known at this time.

Recreation that is focused on riparianareas, particularly during warm summerbreeding months, may also constitute athreat to E. t. extimus. Taylor (1986)found a possible correlation betweenrecreational activities and decreasedriparian bird abundance. Blakesley andReese (1988) reported the willowflycatcher (probably E. t. adastus) as oneof seven species negatively associatedwith campgrounds in riparian areas innorthern Utah. It is unknown whetherthese possible effects involve impacts tohabitat or disturbance of nesting birds.

The Service has carefully assessed thebest scientific and commercialinformation available regarding the past,present, and future threats faced by thisspecies in determining to make this rulefinal. Based on this evaluation, thepreferred action is to list thesouthwestern willow flycatcher asendangered. A decision regardingdesignation of critical habitat for thisspecies is being deferred, and a finaldecision regarding the designation willbe made by July 23, 1995. Criticalhabitat for this species is not nowdeterminable.

Critical HabitatCritical Habitat is defined in section

3 of the Act as (i) the specific areaswithin the area occupied by a species,at the time it is listed in accordancewith the Act, on which are found thosephysical or biological features (I)essential to the conservation of thespecies and (II) that may require specialmanagement considerations orprotection and; (ii) specific areasoutside the geographical area occupiedby a species at the time it is listed, upona determination that such areas areessential for the conservation of thespecies. ‘‘Conservation’’ means the useof all methods and procedures neededto bring the species to a point at whichlisting under the Act is no longernecessary.

Section 4(a)(3) of the Act andimplementing regulations (50 CFR424.12) require that, to the maximumextent prudent and determinable, theSecretary designate critical habitat at thetime a species is determined to beendangered or threatened. Criticalhabitat was proposed to be designatedfor the flycatcher at the time it wasproposed for listing as endangered toencompass approximately 640 miles(1000 km) of riparian zones in the Statesof California, Arizona, and New Mexico.

After reviewing comments submittedduring the public comment period theService is deferring the designation ofcritical habitat for this endangeredspecies. The Service received numerouscomments on the proposed rule,including many recommendations foradditions and deletions to proposedcritical habitat. The Service is reviewingthese comments as well as survey datacollected in 1994. These sourcesincluded more complete information onthe primary constituent elements offlycatcher habitat and on thedistribution of that habitat across thebird’s range. Substantial disagreementhas also been found among scientistsknowledgeable about the speciesregarding the proposed designations.Further, written comments submitted by

State agencies recommended substantialchanges in proposed critical habitatareas.

The Service is presently reconsideringthe prudence of critical habitatdesignation for this species, the need forspecial management considerations orprotection of habitat within the species’range, and the proper boundaries of anyareas that might be designated as criticalhabitat. Issues raised in publiccomments, new information, and thelack of the economic informationnecessary to perform the requiredeconomic analysis cause the Service toconclude that critical habitat is not nowdeterminable and to invoke anextension until July 23, 1995, pursuantto 16 U.S.C. § 1533(b)(6)(C) for reachinga final decision on the proposal ofcritical habitat for the flycatcher. TheService has determined that this is incompliance with provisions of 50 CFR424.12(a) and § 424.17, regardingdelaying final rules on proposed criticalhabitat designations, and withprovisions for addressing State agenciesthat disagree in whole or part with aproposed rule (50 CFR 424.18(c)). Inorder to assist in its deliberation, theService is reopening comment on theproposal to designate critical habitat fora period of 60 days. Comments areparticularly sought on the followingtopics:

1. The need for special managementof areas within the range of theflycatcher, including those proposed ascritical habitat as well as other areas,

2. The net benefit to the flycatcher inaddition to the protection provided byits listing as endangered likely to accruefrom a designation of critical habitat,and

3. Any indication that areas should beadded to or excluded from thoseproposed for designation.

Comments already received thataddress the above topics will beconsidered in reaching a final decisionregarding critical habitat designation,and need not be resubmitted.

Available Conservation MeasuresConservation measures provided to

species listed as endangered orthreatened under the Act includerecognition, recovery actions,requirements for Federal protection, andprohibitions against certain practices.Recognition through listing encouragesand results in conservation actions byFederal, State, and local agencies,private organizations, and individuals.The Act provides for possible landacquisition and cooperation with theStates and requires that recovery actionsbe carried out for all listed species. Theprotection required of Federal agencies


and the prohibitions against taking andharm are discussed, in part, below.

Section 7(a) of the Act, as amended,requires Federal agencies to evaluatetheir actions with respect to any speciesthat is proposed or listed as endangeredor threatened and with respect to itscritical habitat, if any is beingdesignated. Regulations implementingthis interagency cooperation provisionof the Act are codified at 50 CFR Part402. Section 7(a)(4) requires Federalagencies to confer informally with theService on any action that is likely tojeopardize the continued existence of aproposed species or result indestruction or adverse modification ofproposed critical habitat. If a species islisted subsequently, Section 7(a)(2)requires Federal agencies to ensure thatactivities they authorize, fund, or carryout are not likely to jeopardize thecontinued existence of such a species ordestroy or adversely modify its criticalhabitat. If a Federal action may affect alisted species or its critical habitat, theresponsible Federal agency must enterinto consultation with the Service.

No conservation plans or habitatrestoration projects specific to thesouthwestern willow flycatcher exist onlands managed by the U.S. ForestService (USFS), BLM, U.S. Bureau ofReclamation (Reclamation), IndianNations, State agencies, or the Service.The USFS and BLM have focussed someattention on modifying livestock grazingpractices in recent years, particularly asthey affect riparian ecosystems. Asmitigation for other projects impactingriparian habitats, Reclamation isengaged in riparian habitat restorationprojects in several areas in the range ofE. t. extimus, including some historicalnesting locations. The BLM currentlymanages approximately 40 miles of theupper San Pedro River in Arizona(including historic nest sites), as aRiparian National Conservation Area.Riparian habitat rehabilitation is alsounderway at several National WildlifeRefuges in the breeding range of E. t.extimus, which are managed by theService. The Nature Conservancymanages one of the largest remainingflycatcher populations, as well asseveral other areas with high recoverypotential. The U.S. Marines havemaintained a cowbird control programnear the Santa Margarita River to benefitthe least Bell’s vireo. This program hasbenefitted nesting southwestern willowflycatchers there. Grand CanyonNational Park has instituted a seasonalrecreation closure at the remaining sitewith nesting willow flycatchers in theGrand Canyon, and has begun a cowbirdmonitoring program.

The Act and implementingregulations found at 50 CFR 17.21 setforth a series of general prohibitions andexceptions that apply to all endangeredwildlife. These prohibitions, in part,make it illegal for any person subject tothe jurisdiction of the United States totake (includes harass, harm, pursue,hunt, shoot, wound, kill, trap, or collect;or to attempt any of these), import orexport, ship in interstate commerce inthe course of commercial activity, or sellor offer for sale in interstate or foreigncommerce any listed species. It also isillegal to possess, sell, deliver, carry,transport, or ship any such wildlife thathas been taken illegally. Certainexceptions apply to agents of theService and State conservation agencies.

Permits may be issued to carry outotherwise prohibited activitiesinvolving endangered wildlife speciesunder certain circumstances.Regulations governing permits are at 50CFR 17.22 and 17.23. Such permits areavailable for scientific purposes, toenhance the propagation or survival ofthe species, and/or for incidental take inconnection with otherwise lawfulactivities.

It is the policy of the Service (59 FR34272) to identify to the maximumextent practicable at the time a speciesis listed those activities that would orwould not constitute a violation ofsection 9 of the Act. The intent of thispolicy is to increase public awareness ofthe effect of a listing on proposed andongoing activities within a species’range. The Service believes that, basedon the best available information, thefollowing are examples of actions thatwill not result in a violation of section9:

(1) Dispersed recreational activitiesnear willow flycatcher breeding areasthat do not disrupt normal flycatcherbreeding activities and behavior, attractavian and mammalian predators, norresult in the trampling or destruction ofriparian breeding habitat;

(2) Federally-approved projects thatinvolve activities such as discharge offill material, draining, ditching, tiling,pond construction, streamchannelization or diversion, ordiversion or alteration of surface orground water flow into or out of thewetland (i.e., due to roads,impoundments, discharge pipes,stormwater detention basins, etc.)—when such activity is conducted inaccordance with any reasonable andprudent measures given by the Servicein accordance with section 7 of the Act;and

(3) Livestock grazing that does notattract the brood parasitic brown-headedcowbird or result in the destruction of

riparian habitat or the disturbance ofbreeding flycatchers.

Activities that the Service believescould potentially harm thesouthwestern willow flycatcher andresult in ‘‘take,’’ include, but are notlimited to:

(1) Unauthorized handling orcollecting of the species;

(2) Destruction/alteration of thespecies’ habitat by discharge of fillmaterial, draining, ditching, tiling, pondconstruction, stream channelization ordiversion, or diversion or alteration ofsurface or ground water flow into or outof the wetland (i.e., due to roads,impoundments, discharge pipes,stormwater detention basins, etc.);

(3) Livestock grazing that results indirect or indirect destruction of riparianhabitat;

(4) Activities such as continuedpresence of cattle and fragmentation offlycatcher habitat that facilitate broodparasitism by the brown-headedcowbird; and

(5) Pesticide applications in violationof label restrictions.

Questions as to whether specificactivities will constitute a violation ofsection 9 should be directed to Sam F.Spiller or Robert M. Marshall at theService’s Ecological Services StateOffice, 2321 West Royal Palm Road,Suite 103, Phoenix, Arizona 85021(Telephone 602/640–2720)

National Environmental Policy ActThe Fish and Wildlife Service has

determined that an EnvironmentalAssessment and Environmental ImpactStatements, as defined under theauthority of the National EnvironmentalPolicy Act of 1969, need not beprepared in connection with regulationsadopted pursuant to Section 4(a) of theAct. A notice outlining the Service’sreasons for this determination waspublished in the Federal Register onOctober 25, 1983 (48 FR 49244).

References CitedA complete list of all references cited

herein, as well as others, is availableupon request from the Supervisor,Ecological Services State Office inArizona (see ADDRESSES above).

AuthorThe primary author of this rule is

Robert M. Marshall, Ecological ServicesState Office in Arizona (see ADDRESSESabove).

List of Subjects in 50 CFR Part 17Endangered and threatened species,

Exports, Imports, Reporting and recordkeeping requirements, andTransportation.


Regulation Promulgation

Accordingly, part 17, subchapter B ofchapter I, title 50 of the Code of FederalRegulations, is amended as set forthbelow:

PART 17—[AMENDED]

1. The authority citation for Part 17continues 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 byadding the following, in alphabetical

order under Birds, to the List ofEndangered and Threatened Wildlife toread as follows:

§ 17.11 Endangered and threatenedwildlife.

* * * * *(h) * * *

SpeciesHistoric range

Vertebrate popu-lation where endan-gered or threatened

Status When listed Criticalhabitat

SpecialrulesCommon name Scientific name

* * * * * * *BIRDS

* * * * * * *Flycatcher, south-

western willow.Empidonax traillii,

extimus.U.S.A. (AZ, CA, CO,

NM, NV, TX, UT).Entire ..................... E 577 NA NA

* * * * * * *

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

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federal register - Center for Biological Diversity€¦ · southern Utah, Arizona, New Mexico, western Texas, southwestern Colorado, and extreme northwestern Mexico. Within this region,