federal register February 27,1995 Monday Rule Southwestern WillowFlycatcher;Final Endangered andThreatenedSpecies: 50 CFRPart17 Fish andWildlifeService Interior Department ofthe Part III 10693 10694 Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations

DEPARTMENT OF THE INTERIOR hours at Ecological Services State alnorum) were once considered a single Office, U.S. Fish and Wildlife Service, species, the Traill’s flycatcher (E. Fish and Wildlife Service 2321 West Royal Palm Road, Suite 103, traillii). Some sources [American Phoenix, Arizona 85021. Ornithologists’ Union (AOU) 1983, 50 CFR Part 17 FOR FURTHER INFORMATION CONTACT: Sam McCabe 1991] treat E. traillii and E. RIN 1018 AB97 F. Spiller or Robert M. Marshall at the alnorum, and all their subspecies as a above address (Telephone 602/640– superspecies, the ‘‘traillii complex’’. Endangered and Threatened Wildlife 2720). However, the two species are and Plants; Final Rule Determining distinguishable by morphology (Aldrich SUPPLEMENTARY INFORMATION: Endangered Status for the 1951), song type, habitat use, structure Southwestern Flycatcher Background and placement of nests (Aldrich 1953), eggs (Walkinshaw 1966), ecological AGENCY: Fish and Wildlife Service, The southwestern willow flycatcher is Interior. a small , approximately 15 separation (Barlow and McGillivray centimeters (cm) (5.75 inches) long. It 1983), and genetic distinctness (Seutin ACTION: Final rule. has a grayish-green back and wings, and Simon 1988). The breeding range of SUMMARY: The Fish and Wildlife Service whitish throat, light grey-olive breast, the flycatcher generally occurs (Service) determines the southwestern and pale yellowish belly. Two wingbars north of the willow flycatcher’s range. willow flycatcher ( traillii are visible; the eye ring is faint or The southwestern willow flycatcher is extimus) to be an endangered species absent. The upper mandible is dark, the one of five subspecies of the willow under the authority of the Endangered lower is light. The song is a sneezy ‘‘fitz- flycatcher currently recognized Species Act of 1973, as amended (Act). bew’’ or ‘‘fit-za-bew,’’ the call a repeated (Hubbard 1987, Unitt 1987, Browning The breeding range of this bird includes ‘‘whitt.’’ 1993) (Figure 1.). The breeding ranges of The southwestern willow flycatcher southern California, southern Nevada, the widely distributed E. t. traillii and occurs in riparian habitats along rivers, southern Utah, Arizona, New , E. t. campestris extend across the streams, or other wetlands, where dense western Texas, southwestern Colorado, northern United States and southern growths of (Salix sp.), and extreme northwestern Mexico. Canada, from New England and Nova Baccharis, arrowweed (Pluchea sp.), Within this region, the species is Scotia west, through northern Wyoming restricted to dense riparian associations buttonbush (Cephalanthus sp.), tamarisk (Tamarix sp.), Russian olive and Montana, and into British of willow, cottonwood, buttonbush, and Columbia. Hubbard (1987) and Unitt other deciduous shrubs and trees. This (Eleagnus sp.) or other plants are present, often with a scattered overstory (1987) treated E. t. campestris as habitat was historically rare and of cottonwood (Populus sp.) (Grinnell synonymous with E. t. traillii, but sparsely distributed and is currently and Miller 1944, Phillips 1948, Phillips Browning (1993) considered them more rare owing to extensive et al. 1964, Whitmore 1977, Hubbard separate subspecies (Figure 1.). The destruction and modification. The 1987, Unitt 1987, Whitfield 1990, subspecies E. t. adastus breeds from southwestern willow flycatcher is Brown and Trosset 1989, Brown 1991, Colorado west of the plains, west endangered by extensive loss of habitat, Sogge et al. 1993, Muiznieks et al. through the Great Basin States and into brood parasitism, and lack of adequate 1994). Throughout the range of E. t. the eastern portions of California, protective regulations. This rule extimus, these riparian habitats tend to Oregon and Washington. The breeding implements Federal protection provided be rare, widely separated, small and/or range of E. t. brewsteri extends from the by the Act for the southwestern willow linear locales, separated by vast central California coast north, through flycatcher. Designation of critical habitat expanses of arid lands. The western Oregon and Washington to for the southwestern willow flycatcher southwestern willow flycatcher has Vancouver Island. The breeding range of is deferred while the Service gathers experienced extensive loss and the southwestern willow flycatcher (E. t. further comments and reconsiders the modification of this habitat and is also extimus) includes southern California, prudence of designation and the endangered by other factors, including southern Nevada, southern Utah, appropriate boundaries of any area to be brood parasitism by the brown-headed Arizona, New Mexico, and western designated. cowbird (Molothrus ater) (Unitt 1987, Texas (Hubbard 1987, Unitt 1987, DATES: The listing of the southwestern Ehrlich et al. 1992, Sogge et al. 1993, Browning 1993). It may also breed in willow flycatcher is effective March 29, Muiznieks et al. 1994). southwestern Colorado, but nesting 1995. Comments on the designation of The southwestern willow flycatcher records are lacking. Records of probable critical habitat may be submitted until (Order Passeriformes; Family breeding E. t. extimus in Mexico are few April 28, 1995. Tyrannidae) is a subspecies of one of the and are restricted to extreme northern ADDRESSES: The complete file for this ten North American flycatchers in the Baja California del Norte and Sonora rule is available for inspection, by genus Empidonax. The willow (Unitt 1987, Wilbur 1987). appointment, during normal business flycatcher and alder flycatcher (E. BILLING CODE 4310±55±M Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations 10695

BILLING CODE 4310±55±C 10696 Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations

The willow flycatcher subspecies are primarily in willows, buttonbush, and feet) above ground in a medium-sized distinguished primarily by subtle Baccharis, with a scattered overstory of bush or small tree, with dense differences in color and morphology. cottonwood (Grinnell and Miller 1944, vegetation above and around the nest Unitt (1987) noted that these differences Phillips 1948, Whitmore 1977, Unitt (Brown 1988, Whitfield 1990, ‘‘* * * are minor, but differ little in 1987). Following modern changes in Muiznieks et al. 1994). magnitude from those distinguishing the riparian plant communities, E. t. The southwestern willow flycatcher is species E. traillii from E. alnorum. In extimus still nests in native vegetation present and singing on breeding Empidonax, small differences in where available, but has been known to territories by mid-May, although its morphology may mask large differences nest in thickets dominated by tamarisk presence and status is often confused by in biology.’’ and Russian olive (Hubbard 1987, the migrating individuals of northern The subspecies E. t. extimus was Brown 1988, Sogge et al. 1993, subspecies passing through E. t. extimus described by A.R. Phillips (1948) from Muiznieks et al. 1994). Sedgwick and breeding habitat [D. Kreuper, Bureau of a collection by G. Monson from the Knopf (1992) found that sites selected as Land Management (BLM), unpubl. data]. lower San Pedro River in southeastern song perches by male willow flycatchers The southwestern willow flycatcher Arizona. The of E. t. extimus (E. t. traillii/campestris) exhibited builds nests and lays eggs in late May was critically reviewed by Hubbard higher variability in shrub size than did and early June and fledges young in (1987), Unitt (1987), and Browning nest sites and often included large early to mid-July (Willard 1912, Ligon (1993). Hubbard (1987) gave a qualified central shrubs. Habitats not selected for 1961, Brown 1988, Whitfield 1990, endorsement of the validity of E. t. either nesting or singing were narrower Sogge and Tibbitts 1992, Sogge et al. extimus, recommending continued riparian zones, with greater distances 1993, Muiznieks et al. 1994). Some examination of the taxonomy. Unitt between willow patches and individual variation in these dates has been (1987) found that E. t. extimus was willow plants. Nesting willow observed (Carothers and Johnson 1975, distinguishable from other willow flycatchers of all subspecies generally Brown 1988, Muiznieks et al. 1994) and flycatchers by color, being paler, and prefer areas with surface water nearby may be related to altitude, latitude, and morphology (primarily wing formula) (Bent 1960, Stafford and Valentine 1985, renesting. but not overall size. Browning (1993) Harris et al. 1987), but E. t. extimus The southwestern willow flycatcher is also found that E. t. extimus was virtually always nests near surface water an insectivore. It forages within and distinguishable as a more pale-colored or saturated soil (Phillips et al. 1964, above dense riparian vegetation, taking subspecies. The song dialect of E. t. Muiznieks et al. 1994). At some nest on the wing or gleaning them extimus may also be distinguishable sites surface water may be present early from foliage (Wheelock 1912, Bent from other willow flycatchers. Rather in the breeding season but only damp 1960). It also forages in areas adjacent to than the crisp, sneezy ‘‘fitz-bew’’ of the soil is present by late June or early July nest sites, which may be more open (M. northerly subspecies, E. t. extimus sings (Muiznieks et al. 1994, M. Whitfield, Sogge, National Biological Survey, pers. a more protracted, slurred ‘‘fit-za-bew,’’ Kern River Research Center, in litt.- comm. 1993). No information is with a burry ‘‘bew’’ syllable (recordings 1993, J. and J. Griffith, Griffith Wildlife available on specific prey species. by M. Sogge and J. Travis). The Biology, in litt.-1993). Ultimately, a The migration routes and wintering subspecies E. t. extimus is accepted by water table close enough to the surface grounds of E. t. extimus are not well most authors (e.g., Aldrich 1951, Behle to support riparian vegetation is known. Empidonax flycatchers rarely and Higgins 1959, Phillips et al. 1964, necessary. Bailey and Niedrach 1965, Oberholser Defining a minimum habitat patch sing during fall migration, so that a 1974, Monson and Phillips 1981, Harris size required to support a nesting pair means of distinguishing subspecies is et al. 1987, Schlorff 1990, Harris 1991). of E. t. extimus is difficult. Throughout not available (Blake 1953, Peterson and Section 3(15) of the Act and regulations its range, determining the capability of Chalif 1973). However, willow at 50 CFR 424.02(k) defines the term habitat patches to support southwestern flycatchers have been reported to sing ‘‘species’’ as any subspecies of fish or willow flycatchers is confused by the and defend winter territories in Mexico wildlife or plants, and any distinct species’ rarity, unstable populations, and (Gorski 1969, population segment of any vertebrate variations in habitat types, and other McCabe 1991). The southwestern species which interbreeds when mature. factors. However, the available willow flycatcher most likely winters in Based on the above information, the information indicates that habitat Mexico, Central America, and perhaps Service has determined that E. t. patches as small as 0.5 hectare (ha) (1.23 northern (Phillips 1948, extimus is eligible for protection under acres) can support one or two nesting Peterson 1990). However, the habitats it the Act. pairs. Sogge et al. (1993) found uses on wintering grounds are The southwestern willow flycatcher territorial flycatchers in habitat patches unknown. Tropical deforestation may nests in thickets of trees and shrubs ranging from 0.5 to 1.2 ha (1.23 to 2.96 restrict wintering habitat for this and approximately 4–7 meters (m) (13–23 acres). Two habitat patches of 0.5 and other neotropical migratory (Finch feet) or more in height, with dense 0.9 ha (1.23 and 2.2 acres) each 1991, Sherry and Holmes 1993). foliage from approximately 0–4 m (13 supported two territories. Muiznieks et Breeding bird survey data for 1965 feet) above ground, and often a high al. (1994) also reported groups of through 1979 combined the willow and canopy cover percentage. The diversity territorial E. t. extimus in habitat alder flycatchers into a ‘‘Traill’s of nest site plant species may be low patches of approximately one to several flycatcher superspecies’’, because of (e.g., willows) or comparatively high hectares. taxonomic uncertainty during the 15- (e.g., mixtures of willow, buttonbush, The nest is a compact cup of fiber, year reporting period. These data cottonwood, boxelder, Russian olive, bark, and grass, typically with feathers showed fairly stable numbers in central Baccharis, and tamarisk). Nest site on the rim, lined with a layer of grass and eastern North America but strong vegetation may be even- or uneven-aged, or other fine, silky plant material, and declines in the West, the region but is usually dense and structurally often has plant material dangling from including the range of the southwestern homogeneous (Brown 1988, Whitfield the bottom (Harrison 1979). It is willow flycatcher, and where the alder 1990, Sogge et al. 1993, Muiznieks et al. constructed in a fork or on a horizontal flycatcher is absent (Robbins et al. 1994). Historically, E. t. extimus nested branch, approximately 1–4.5 m (3.2–15 1986). Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations 10697

Unitt (1987) reviewed historical and 1993. Appropriate State agencies, comments received during the comment contemporary records of E. t. extimus county governments, Federal agencies, period are addressed in the following throughout its range, determining that it scientific organizations, and other summary. Comments of a similar nature had ‘‘declined precipitously,’’ and that interested parties were contacted and are grouped into a number of general ‘‘although the data reveal no trend in requested to comment. Newspaper issues. the past few years, the population is notices inviting public comment were Issue 1: The American Ornithologists’ clearly much smaller now than 50 years published in the following newspapers; Union (AOU) did not list E. t. extimus ago, and no change in the factors In California, Los Angeles Times, L.A. in its latest Checklist of North American responsible for the decline seem likely.’’ Watts Times, Kern Valley Sun, and San Birds; Unitt (1987) could not distinguish Data are now available that indicate Diego Union-Tribune; in Arizona, E. t. extimus by color or morphology; continued declines, poor reproductive Arizona Daily Sun, Arizona Republic, genetic analysis is necessary to performance, and/or continued threats Tucson Daily Citizen, White Mountain distinguish subspecies; significant for most remaining populations (Brown Independent, and Arizona Daily Star; in disagreement exists among scientists 1991, Whitfield and Laymon, Kern River New Mexico, Albuquerque Journal, regarding taxonomy, for example, Research Center, in litt. 1993, Sogge and Albuquerque Tribune, Santa Fe New McCabe (1991) did not recognize E. t. Tibbitts 1992, Sogge et al. 1993, Mexican, Carlsbad Current-Argus, Silver extimus; the willow flycatcher Muiznieks et al. 1994). City Daily Press; in Nevada, Las Vegas subspecies, in fact the North American Sun; in Colorado, Durango Herald; in Empidonax flycatcher species are too Previous Federal Actions Utah, Daily Spectrum; and in Texas, El difficult to distinguish to make it The Service included the Paso Times. The inclusive dates of reasonable to list subspecies of those southwestern willow flycatcher on its publications were August 31 through species; hybridization of the willow Notice of Review as a category September 13, 1993, for the initial flycatcher subspecies occurs; subspecies 2 candidate species on January 6, 1989 comment period and October 28 are not worth listing; E. t. extimus is a (54 FR 554). A category 2 species is one through November 5, 1993, for the subspecies of a very common species; E. for which listing may be appropriate but public hearings and extension of public t. extimus is not worth listing because for which additional biological comment period. it is one of nine common species in the information is needed. After soliciting The Service held six public hearings. genus Empidonax; this subspecies and and reviewing additional information, Because of anticipated interest in the subspecies in general are of minor the Service elevated E. t. extimus to proposed rule, the Service announced ecological value; their loss would be category 1 candidate status on its intention to hold at least three public unimportant; there is little value in November 21, 1991 (56 FR 58804). A hearings. In response to requests from preserving rare species/subspecies; and category 1 species is one for which the the public, three additional hearings historical taxonomic questions may Service has on file substantial were scheduled. A notice of the hearing confuse population trend information. information to support listing, but for dates and locations was published in Service Response: The Service has which a proposal to list has not been the Federal Register on October 18, determined that E. t. extimus is a valid issued because it is precluded at present 1993 (58 FR 53702). Approximately 424 taxon. The Service relies on the most by other listing activity. people attended the hearings. About 17 current and authoritative data available On January 25, 1992, a coalition of people attended the hearing in Tucson, in making decisions regarding the conservation organizations (Suckling et Arizona; 27 in Flagstaff, Arizona; 10 in validity of species, subspecies, or al. 1992) petitioned the Service, Las Cruces, New Mexico; 12 in distinct vertebrate population segments. requesting listing of E. t. extimus as an Albuquerque, New Mexico; 350 in Lake These data include articles published in endangered species under the Act. The Isabella, California; and 8 in San Diego, professional journals, agency reports, petitioners also requested emergency California. Transcripts of these hearings and other unpublished data provided by listing and designation of critical are available for inspection (see researchers. For the southwestern habitat. On September 1, 1992, the ADDRESSES). willow flycatcher, the Service reviewed Service published a finding (57 FR A total of 3,102 written comment this information and found a majority 39664) that the petition presented letters were received at the Service’s opinion that E. t. extimus is a valid substantial information indicating that Ecological Services State Office in subspecies. Authorities who critically listing may be warranted and requested Arizona: 264 supported the proposed examined the taxonomy of E. traillii and public comments and biological data on listing; 2,650 opposed the proposed recognized E. t. extimus include Phillips the species. On July 23, 1993, the listing; and 188 expressed neither (1948), Aldrich (1951), Hubbard (1987), Service published a proposal (58 FR support nor opposition, but either Unitt (1987), and Browning (1993). 39495) to list E. t. extimus as commented on information in the Other authorities accepting the endangered with critical habitat, and proposed rule, provided additional subspecies include Behle and Higgins again requested public comments and information, or were non-substantive or (1959), Phillips et al. (1964), Bailey and biological data on the southwestern irrelevant to the proposed listing. Niedrach (1965), Oberholser (1974), willow flycatcher. Oral or written comments were Monson and Phillips (1981), Harris et al. received from 62 parties at the hearings: (1987), Schlorff (1990), Whitfield (1990), Summary of Comments and 8 supported the proposed listing; 40 Brown (1991), Harris (1991), Western Recommendations opposed the proposed listing; and 14 Foundation for Vertebrate Zoology in In the July 23, 1993, proposed rule (58 expressed neither support nor litt. 1993, University of California in litt. FR 39495) and associated notifications, opposition but provided additional 1993. The AOU (1983) did not list all interested parties were requested to information, or were non-substantive or subspecies of any bird, including the submit comments or information that irrelevant to the proposed listing. willow flycatcher, in its 1983 Checklist might bear on whether to list the In total, oral or written comments of North America Birds. However, this southwestern willow flycatcher. The were received from 31 Federal and State does not indicate a lack of recognition comment period was originally agencies and officials, 17 local officials, of E. t. extimus, or for the concept of scheduled to close October 21, 1993, and 3,116 private organizations, subspecies. The preface to the 1983 then was extended to November 30, companies, and individuals. All Checklist states ‘‘The Committee 10698 Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations strongly endorses the concept of the Service Response: The Service is overstated, poorly documented, and subspecies * * * and we wish to make unaware of any study, report, or species does not constitute a threat to the it clear that the omission of separate account that describes E. t. extimus as flycatcher; the statement that 90 percent listings of subspecies in this edition is anything but a riparian obligate. No loss of riparian habitat has occurred is not a rejection of the validity or utility commenter provided data, studies, or inaccurate and an exaggeration; riparian of this systematic category * * *.’’ reports indicating that E. t. extimus habitat has not decreased, but increased The Service noted McCabe’s (1991) nests outside riparian habitats. Several as a result of diversions, irrigation, etc; consideration of the willow and alder commenters cited field guides which habitat has increased, not decreased, in (E. alnorum) flycatchers as a single describe the willow flycatcher (all local area(s) over the past 20 years; species, and his reluctance to recognize subspecies) as occurring ‘‘* * * in riparian regeneration is approaching willow flycatcher subspecies. McCabe drier situations (than the alder 1,000 percent in southeastern Arizona; (1991) provides a thorough review of the flycatcher) * * *’’ (Peterson 1990), Hastings and Turner (1965) show that history of E. alnorum and E. traillii ‘‘* * * on brushy slopes * * *’’ cottonwood riparian habitat has taxonomy, and the questions of (Robbins et al. 1983), and ‘‘* * * dry, increased in southeastern Arizona; the ecological, morphological, and song- brushy upland pastures * * *’’ upper San Pedro River is recovered, not type distinction on which this (National Geographic Society 1990). The ‘‘unsuitable and unoccupied’’ as the taxonomic evaluation has been based. Service believes that field guide species Service claimed; because tamarisk has However, the Service agrees with accounts do not constitute the best increased, and E. t. extimus uses Sedgwick’s (1993) comments and available scientific information on tamarisk, tamarisk invasion does not McCabe’s own observation that McCabe biology, ecology or habitat constitute modification of habitat, but (1991) contrasts with the majority requirements. Field guide accounts tend expansion of habitat; population opinion regarding taxonomy of the to be brief and generalized, and in this declines in the past 20 years are willow and alder flycatchers. case represent habitat use of other concurrent with improved riparian After examining 305 study skins, willow flycatcher subspecies, which habitats, so no correlation exists Unitt (1987) found that while four occur in more mesic regions. Similarly, between trends in habitat and subspecies (E. t. traillii, E. t. adastus, E. Barlow and McGillivray’s (1983) populations; the proposal fails to t. brewsteri, and E. t. extimus) could be description of willow flycatchers (E. t. support claims that urban development, tentatively separated by the ‘‘75 percent campestris/traillii) selecting ‘‘* * * a agriculture, and livestock grazing are rule’’ using overall size (wing and tail more xeric upland habitat * * *’’ in harmful to the flycatcher. lengths and their ratios to one another), Ontario, Canada, is not considered Service Response: The Service has determined that the documentation of these criteria were not satisfactorily relevant to habitat selection of E. t. loss and modification of southwestern conclusive. However, he found that the extimus in the desert Southwest. In the riparian habitats, cited in this final rule, subspecies could be satisfactorily wetter climates of the north, upper is adequate. Regarding the ‘‘90 percent distinguished, under the ‘‘75 percent midwest, and northeast, habitat loss and modification’’ statement, the rule,’’ using color, wing formula conditions of moist soil or surface proposed rule stated that ‘‘* * * as (relative lengths of primary wing water, supporting thickets of deciduous much as 90 percent * * *’’ (emphasis feathers), or both. Browning (1993) shrubs and trees, are not restricted to added) has been lost or modified. The examined 270 specimens and found that riparian areas. However, in the arid actual percentage lost or modified is not all four subspecies, and a fifth (E. t. Southwest where E. t. extimus occurs, expected to be consistent across the these conditions are limited to riparian campestris) were distinguishable by region, but should vary with elevation, areas, usually in profound contrast to color. rainfall, geographic area, relative size of the adjacent and prevailing desert The Service acknowledges that drainage system, and severity of conditions. Various authors (e.g., King taxonomy of E. traillii races continues to impacts. Loss and modification may be 1955) have noted that while willow pose questions and may be revised in lesser at higher elevations, where flycatchers may nest away from riparian the future. The Service has determined precipitation is greater and evaporation areas in the north and east, in arid that E. t. extimus is a sufficiently less. In most major lower elevation regions (the ranges of E. t. brewsteri and distinct entity to be listed under the Act desert riparian systems, loss or at the very least as a distinct vertebrate E. t. extimus particularly) the species is modification may in fact be near 100 population [50 CFR § 424.02(k)]. restricted to riparian habitats. Regarding percent, e.g., the lower Colorado, lower However, the Service accepts the the presence of surface water during the Gila, lower Rio Grande, and lower Salt majority opinion that E. t. extimus is a breeding season, new information was Rivers. Because ‘‘modification’’ includes valid subspecies and lists it as such. provided indicating that some nest sites alterations in flow regimes, channel The Service considers taxonomic have surface water in close proximity confinement, changes in water quality, distinctness in assigning priorities for early in the breeding season, which and floristic makeup of riparian species listings, but not in determining recedes underground by the end of the systems, the Service believes it is not a whether or not to list species. The Act breeding season. At these sites, the misrepresentation to state that up to 90 authorizes listing of species, subspecies, water table remains at least high enough percent of southwestern riparian or distinct population segments, all of to sustain riparian vegetation. The ecosystems have been lost or modified. which have ecological significance. Service is unaware of any surveys Commenters stating that riparian Issue 2: The southwestern willow performed in non-riparian habitats habitat has not decreased, but increased flycatcher is not a riparian obligate specifically to verify the absence of as a result of diversions and irrigation, species. It also occurs in open prairie nesting E. t. extimus. However, the presented no supporting information. woodlots, dry and brushy pastures, and Service relied on local, State, and The Service recognizes that some brushy fields or slopes. No surveys of regional species accounts of distribution diversions, particularly unmaintained dry habitats have been done to prove and habitat use, none of which describe irrigation ditches, sometimes support riparian obligacy. The southwestern occurrence outside of riparian habitats. riparian vegetation. However, the willow flycatcher does not ‘‘invariably’’ Issue 3: The loss and modification of Service believes diversion and irrigation nest near surface water. southwestern riparian habitat is result in a net loss of riparian habitat. Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations 10699

Where riparian vegetation becomes described as a common nester in Glen to result in population declines. In established along irrigation systems, it is Canyon prior to inundation (Behle and many cases, population declines are often cleared away at regular intervals. Higgins 1959, Behle 1985), indicating inferred from decline in habitat Where it is not, it is sometimes because that this historic habitat was of higher availability. However, in this and other an artificially created riparian/wetland quality than the new habitat in Grand listing determinations, the Service seeks habitat is being maintained as Canyon. to measure such inference against mitigation or compensation for loss of Issue 4: The flycatcher has always whatever population trend data are natural riparian habitat elsewhere. been a rare bird, so its rarity now is no available. Regarding concerns over The Service recognizes that in some change from historical situations; sources of these data, the Service local areas in recent decades, riparian historical specimens are few, indicating endeavors to verify accuracy and habitat has been rehabilitated or the bird was always rare; population credibility of data. The reports increased, not decreased. However, the data are insufficient to show decline; published by government agencies, Service accepts the consensus of population data are suspect, developed academic institutions, and professional literature cited in this rule that the by parties with agendas of land control/ journals on which this determination is overall trend continues to be one of acquisition; the flycatcher is not based are accepted as credible. To habitat loss. declining in all areas; historical interpret population trends in the light Hastings and Turner (1965) and Bahre taxonomic questions may confuse of changing taxonomic status, the (1991) noted that riparian habitats were population trend information; accuracy Service considered all information for already significantly altered by the turn or existence of population trend data for willow flycatchers in the current range of the last century. Hastings and Turner the last 50 years is questionable; of E. t. extimus to be relevant. (1965) also noted that all major population sampling techniques were Issue 5: Livestock grazing is not a watercourses in southern Arizona not discussed; these could bias trend threat to E. t. extimus or its habitat; suffered entrenchment and became studies; population data are incomplete; Montgomery et al. (1985) found 53 more ephemeral in flow in the proposal relies on data reflecting singing birds in a grazed area in New approximately 1890. Land use practices loss of habitat rather than Mexico; on Marine Corps Base Camp that had already affected riparian comprehensive population trend Pendleton, E. t. extimus is increasing habitats in this Arizona-Mexico border analysis; there are no recent collections where sheep graze; nest disturbance by region included livestock grazing, of E. t. extimus from southern Arizona cattle is unsubstantiated; southwestern woodcutting, and water diversion; riparian areas. flora evolved with large grazing climatic changes may also have Service Response: The Service agrees ungulates; the proposed rule lacks contributed. The differences between that the flycatcher has probably always examples of flycatcher status improving the historic and more recent been sparsely distributed, as a function with reduction in livestock or improved photographs show some riparian of the sparse distribution of its wetland livestock management; E. t. extimus is recovery, concurrent with reductions in habitat in a predominantly xeric region. not improving in areas with no grazing; livestock stocking levels from their However, sparse distribution and rarity the proposed rule equates any livestock highs in the late 1800’s. No data, or are not necessarily equivalent. At grazing with overgrazing, and fails to elaboration, were presented to support individual locales the flycatcher may distinguish between overgrazing and statements that riparian regeneration is occur in considerable numbers, as well-managed grazing; proper livestock approaching 1000 percent in indicated by Herbert Brown’s collection management is compatible with healthy southeastern Arizona. of 36 nests near Yuma in 1902, and the riparian habitat; some level of livestock As this final rules discusses, E. t. persistence of several populations of grazing is compatible with/necessary for extimus sometimes nests in tamarisk, considerable numbers (30–40 pairs) in healthy riparian ecosystems; willows but does so at lower densities, and relatively small areas like the Kern River are brush, which cattle don’t eat, but apparently at lower success rates than in Preserve in California (Harris et al. cattle are blamed for both brush native vegetation (Hunter et al. 1988, 1986, Whitfield 1990). Although E. t. encroachment and brush destruction; Sogge et al. 1993, Muiznieks et al. extimus habitat is rare, where it is cattle trample stream banks, which 1994). Therefore, tamarisk invasion present nesting pairs may occur in allows water to escape, creating more likely represents replacement of native relatively high densities. This riparian habitat; livestock grazing habitat with lower-quality habitat, phenomenon has caused some authors prevents urbanization of land, which rather than an increase in habitat to describe E. t. extimus as something of would have a greater impact on riparian availability. Only in a few unique a colonial nester (e.g., Unitt 1987). habitats. situations does tamarisk truly represent Regarding the lack of historic or Service Response: The proposed and ‘‘new’’ habitat. For example, in the recent specimens available from various final rules discuss overuse by livestock Grand Canyon flycatchers nest in a parts of the bird’s range, the Service as a threat to E. t. extimus, through ‘‘new’’ riparian habitat, dominated by notes that specimen collection is largely impacts on riparian habitat. The Service tamarisk (Carothers and Brown 1991). a function of collecting activity, not recognizes that what constitutes This new riparian habitat became simple presence of the subject. ‘‘overuse’’ varies with differing riparian established in the historic flood-scour The Service agrees that, as with many ecosystems, elevation, type of livestock, zone of the , after non-game species, population trend data seasonality of use, and other factors. construction of Glen Canyon Dam are incomplete. No wide scale, and few The Service believes that some livestock eliminated annual scouring floods. local studies have been funded or grazing regimes are likely to be found However, flycatchers nest in this area in undertaken to track this species through compatible with rehabilitation and low numbers (Brown 1991, Sogge and time. Comprehensive, long-term maintenance of E. t. extimus habitat. Tibbitts 1992, Sogge et al. 1993) and population data are not necessarily Montgomery et al. (1985) did not have low nesting success. It is required for making listing determine whether the willow noteworthy that by forming Lake determinations. Rather, these decisions flycatchers they detected on grazed land Powell, Glen Canyon Dam also often rest upon data on loss and were resident E. t. extimus or migrating inundated habitat in Glen Canyon. The modification of habitat and other individuals of other subspecies. Further, southwestern willow flycatcher was threats, which are reasonably assumed neither grazing intensity nor nesting 10700 Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations success were quantified, so that no detrimental, in fact have increased southeastern Canada. Through the 27 correlations can be made. On Camp riparian habitat (Glen Canyon Dam years of the BBS, cowbird populations Pendleton, increases in E. t. extimus resulted in creation of riparian habitat have remained fairly stable, with a small were concurrent with livestock (sheep) in Grand Canyon); impoundments increase in the 1970’s, small decrease in grazing but also with an extensive protect habitat by preventing the 1980’s, and slight increase in recent cowbird trapping program (Griffith and catastrophic floods; the proposal had years; however, the West has Griffith 1993). Finally, as discussed in inadequate discussion of water experienced a marked population this rule, examples exist of E. t. extimus impoundments as threat. increase over the last five years (and other E. traillii subspecies) Service Response: As discussed (Wiedenfeld 1993). numbers and habitat increasing as a elsewhere in this final rule, water The association of cowbirds with result of grazing reductions or other impoundments have a variety of effects domestic livestock is detailed in the improvements in livestock management. on riparian habitats. The Service has sources cited in this final rule. The The Service recognizes that determined that, with respect to E. t. Service has neither found nor been southwestern riparian ecosystems extimus, the net effect of these provided information indicating that evolved with native grazing ungulates influences is negative. For example, cowbirds are associated with deer or (e.g., deer and elk). However, domestic Glen Canyon Dam eliminated massive elk. Other factors, including habitat livestock do not forage, herd or move in annual scouring floods in the Grand fragmentation and urban/suburban the same manner as native species. Canyon. This resulted in the feeding, are likely to have contributed to Further, elk occur at higher elevations of development of a new riparian zone increases in cowbirds. These causal the Southwest, and are absent from the dominated by tamarisk (Carothers and factors will be important to address in lowland river systems that constitute Brown 1991). However, flycatchers nest the section 7 consultation process and the majority of E. t. extimus habitat. there in very low numbers and with low the development of recovery actions. Issue 6: Timber harvesting is not a nesting success (Brown 1991, Sogge and However, it is the threat of parasitism, threat to the flycatcher’s riparian Tibbitts 1992, Sogge et al. 1993). In regardless of cause, that in part habitat. contrast, E. t. extimus was described as necessitates listing. Service Response: The proposed rule a common nester in Glen Canyon (Behle Where high parasitism rates are found noted that the petitioners claimed and Higgins 1959, Behle 1985), prior to in E. t. extimus nesting locations in timber harvest caused watershed its inundation by Lake Powell. areas with no livestock grazing at the changes which could result in damage Issue 8: Comments concerning the nest site, there have been livestock to riparian habitats through increasing ecology of cowbirds and cowbird nearby that provide feeding sites in intensity and frequency of floods. The parasitism included the following: close enough proximity to facilitate petitioners presented no specific Breeding Bird Survey (BBS) data cowbird parasitism. Cowbirds may information on this claim. A number of indicate that cowbirds have declined, disperse up to 7 kilometers (km) from experimental treatments on not increased; the claim that cowbirds their daily feeding/roosting sites to areas Southwestern forested watersheds have are associated with livestock is not with host species (Rothstein et al. 1984). demonstrated increased peak and flood supported; cowbirds are associated with At the Kern River Preserve, the riparian flows as a result of timber harvest (Tecle deer and elk, not cows; the cowbird habitat supporting E. t. extimus is not 1991). The degree to which timber threat is a natural one; there is grazed, but the immediately adjacent harvesting has affected riparian habitats inconclusive evidence that cowbird lands are. Similarly, although livestock inhabited by the willow flycatcher, increases are directly connected with grazing does not occur in Grand Canyon however, has not been quantified and is livestock grazing; cowbird parasitism of National Park, open range grazing and unknown. The Service did not implicate E. t. extimus is known in areas without an introduced bison herd occur on timber harvesting in the proposed rule livestock grazing (e.g., Grand Canyon, adjacent lands. Further, cowbirds as a major cause of riparian habitat loss. Kern River); there is no correlation concentrate at pack animal corrals at Rather, it pointed to that activity as one between livestock grazing in riparian various points within the National Park of many factors potentially responsible areas and cowbird parasitism; Taylor (Johnson and Sogge 1993). Thus, for riparian habitat loss and (1986) showed that cowbirds were most flycatcher habitat may be ungrazed but modification. Pending new information abundant in areas with long-term still be affected by cowbirds, by having demonstrating otherwise, the Service livestock exclusion; because flycatchers livestock concentrations nearby to serve still considers timber harvesting a and cowbirds are positively associated as cowbird feeding sites. potential threat to riparian habitat (they tend to occur together), flycatchers Cowbirds and E. t. extimus are through loss and modification. can coexist with cowbirds; there is positively associated because cowbirds However, the Service does not believe inconclusive evidence that cowbird require, and therefore associate with, that this threat exists rangewide, nor parasitism is responsible for declines in prospective hosts. The Service finds that does it believe that timber harvesting nesting success; cowbirds have extensive information indicates cowbird alone is responsible for riparian habitat increased as a result of increases in bird parasitism negatively affects the loss or the endangered status of the feeders, campgrounds, etc. and southwestern willow flycatcher. This southwestern willow flycatcher. increases in wintering food/habitat; the information includes specific examples All causal factors will be addressed in proposed rule cited no studies that of parasitism of E. t. extimus, cited in the recovery planning process, and documented cowbird parasitism of E. t. this rule, and examples of the effects of through the Act’s section 7 consultation extimus; citations regarding parasitism cowbird parasitism on other rare species process, through which Federal agencies of other species are irrelevant. Section of limited habitat. Recent information will be responsible for evaluating the 4(a)(1)(E) of the Act allows listing continues to document high parasitism effects of activities such as timber species because of ‘‘* * * natural or rates for E. t. extimus (Sogge et al. 1993, harvest on the flycatcher’s riparian manmade factors affecting its continued Muiznieks et al. 1994), and increases in habitat. existence * * *.’’ flycatcher reproduction or populations, Issue 7: Water impoundments have Service Response: Cowbird numbers concurrent with reductions in cowbird been beneficial, not detrimental; appear to be declining only in the numbers (Griffith and Griffith 1993, M. fluctuating flows below dams are not northeastern United States and Whitfield in litt.—1993). Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations 10701

Issue 9: Tamarisk is not an invader Brown’s collections themselves may activities take place near habitat, or species, but a successional stage, suggest that populations at that time when recreation takes place within or becoming established on recently- could sustain such collecting pressure. adjacent to the nest stand. Because nest scoured areas; livestock do eat tamarisk The origin of Brown’s collections from stands tend to be very dense, virtually for its salt content; the Service needs to several specific locales suggests that E. impenetrable thickets, often with clarify the positive and negative t. extimus was an abundant nesting bird swampy conditions, recreational characteristics of tamarisk; tamarisk in the area of the confluence of the Gila impacts are not expected to occur often. increases habitat availability, in fact and Colorado rivers. Collection of 36 Elk and deer use riparian habitats for provides high-quality bird habitat. nests would have impacted foraging, but generally behave Service Response: The Service found reproduction alone, only for 1902, when differently than domestic livestock. no information, and was not provided all but one of the nests was collected. They tend not to occur in large any information by commenters, Considering continued habitat loss, and concentrations and remain in riparian indicating that tamarisk is primarily a increasing cowbird populations since areas for long periods like domestic successional stage vegetation type, 1902, the Service does not believe that cattle. The Service is aware that elk can rather than an invasive exotic. This final Brown’s collection of 36 nests with eggs impact riparian systems when their rule presents an updated discussion of in 1900 and 1902 significantly affects E. numbers reach high levels. However, elk tamarisk ecology, supported by t. extimus populations in 1995. are lacking from the majority of additional literature references. The However, the Service believes that southwestern willow flycatcher habitats, Service concurs with the consensus current flycatcher populations are because these riparian areas occur at among published authorities that unlikely to be able to sustain collecting lower elevations than elk. Beaver cut tamarisk is an invasive, usually pressures like Brown’s activities of and use willow and cottonwood, but dominant exotic plant, not a 1902. In 1993, extensive surveys of the may also be important in creating quiet- successional species. Commenters that region of Brown’s collections located water riparian habitats by damming stated livestock eat tamarisk for its salt only four to five territories (Muiznieks smaller and steeper creeks. content provided no supporting et al. 1994). Issue 14: The presence of unoccupied information. The Service’s Issue 11: Drought has impacted habitat indicates that E. t. extimus is not understanding of the literature is that habitat. currently habitat limited. cattle prefer native species over Service Response: The Service Service Response: As discussed in tamarisk for forage. recognizes that extended droughts are this rule, the Service has determined As discussed in this rule, E. t. extimus likely to have impacted E. t. extimus that E. t. extimus has suffered extensive has been documented nesting in through habitat reduction. This natural habitat loss, which is complicated by tamarisk at elevations above phenomenon and human-induced the current low number of flycatchers, approximately 625 m (2000 feet). Rather habitat impacts may exacerbate one and reduction of reproductive output than attempt to present criteria here for another’s effects on E. t. extimus habitat. due to brood parasitism by brown- when tamarisk eradication presents a Issue 12: Predators such as snakes, headed cowbirds. The current existence threat or a positive recovery action, the hawks, ravens, grackles, and domestic of apparently suitable habitat that is not Service will address this issue on a case- cats are threats to E. t. extimus. occupied by E. t. extimus more likely by-case basis through the section 7 Service Response: The Service agrees indicates that its numbers are too low to consultation process with other Federal that these constitute potential predators fill all available habitat. Further, habitat agencies. This will allow Federal of songbirds, including E. t. extimus. exists in isolated, fragmented patches. agencies the flexibility to consider While predation would not normally be With low population numbers and individual cases in the light of the expected to be a major threat to the inhibited reproduction, E. t. extimus specific circumstances surrounding flycatcher, its populations may be so may be unable to maintain local each one. low currently that they cannot populations, much less be able to Although Brown and Trosset (1989) withstand normal predation. Further, disperse and colonize unoccupied suggested that tamarisk provided an several of these types of predation may locales. ‘‘ecological equivalent’’ to native be facilitated by habitat alteration or Issue 15: Cowbird parasitism is the vegetation, they qualified this statement. other human actions. Therefore, the main threat to E. t. extimus, not habitat They noted that their study involved Service will address predation in loss; cowbird control is the primary small sample sizes, and that their recovery planning, and other Federal recovery need, not habitat protection; methods differed from Whitmore’s agencies should consider the effects of cowbird trapping would eliminate the (1975, 1977), which was their basis for their actions on some of these forms of need for designating critical habitat; the comparison with native riparian predation. Service should implement and fund habitats. Further, Brown and Trosset Issue 13: Hikers, elk, deer, and beaver cowbird control programs instead of (1989) noted that this ‘‘ecological are threats to flycatcher nests and listing. equivalent’’ function may be most habitat; listing would cause restrictions Service Response: The Service has significant where tamarisk became on fishing and water recreation. determined that cowbird parasitism is established where no native riparian Service Response: No information was one of several primary threats to E. t. vegetation existed previously (e.g., the provided to support statements that extimus, which also includes the loss Colorado River in Grand Canyon). hikers constitute a threat to E. t. and modification of habitat. Cowbird Issue 10: Herbert Brown’s collection extimus. This rule briefly discusses parasitism and loss and modification of of 36 nests with eggs from the lower possible impacts of recreation on E. t. habitat are interrelated. Cowbird Colorado River, in 1900 and 1902, extimus and its habitat. These impacts parasitism is a function not just of indicates overcollection for science may are expected to be primarily effects on cowbird abundance, but also habitat have caused declines. vegetation through soil compaction, quality. Potential host species in Service Response: The effects of clearing vegetation, and creating trails. degraded, fragmented habitat are more Brown’s collections on populations over Because E. t. extimus is not a timid susceptible to nest parasitism than those 90 years ago are unknown. These effects species, disturbance is expected to be an nesting in larger tracts of dense, may have been significant. However, impact only when continuous intrusive contiguous habitat. Cowbird parasitism 10702 Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations will probably remain an imminent flycatchers and that still have potential southern California and central Arizona. threat until habitat rehabilitation is willow flycatcher habitat. Urban and suburban development also accomplished. The Service The Service recognizes that increase demands on river systems for acknowledges that cowbird control taxonomic questions may arise water and hydropower. Thus, should be an immediate, high priority concerning flycatchers occupying some expanding urban centers can result in recovery action. However, cowbird high-elevation locales within the range dewatering or alteration of riparian control is a ‘‘stop-gap’’ action. of E. t. extimus. Because the genetic systems tens or hundreds of miles away. Rehabilitating riparian habitat to make relatedness of willow flycatchers For example, the water and power E. t. extimus and other riparian birds breeding at some high elevation areas, demands of Los Angeles, Phoenix and less susceptible to cowbird parasitism such as the White Mountains of Las Vegas result in effects on the will be necessary for a long-term Arizona, may be substantial, willow Colorado River hundreds of miles from solution. Ultimately, the ranking of flycatchers in those locales should be any of these cities. threats in order of severity is not considered E. t. extimus until further Issue 19: The primary threat to E. t. relevant to the listing question. It is research demonstrates otherwise. extimus is loss of wintering habitat in because a number of often Protection of these breeding groups Central and South America, or other interdependent threats exist that listing could be critical for population factors along migration routes; the E. t. extimus is necessary. Ranking recovery, immigration, and exchange of proposed rule contained insufficient threats in order of severity and genetic material within a highly- information on migration studies; addressing them accordingly will be fragmented landscape. protecting breeding grounds is not part of the recovery process. Issue 17: It is inappropriate to use logical, because E. t. extimus spends Issue 16: Willow flycatchers nesting data from E. t. brewsteri and E. t. eight months of the year in migration or in the northern States, Alaska, and adastus to support listing E. t. extimus; on wintering grounds. Canada are subspecies other than E. t. information cited on livestock damaging Service Response: Although tropical extimus. The boundaries of the breeding nests comes from other subspecies. deforestation possibly may restrict range of E. t. extimus should be Service Response: The Service wintering habitat of the willow expanded to include the Santa Ynez carefully considered the propriety of flycatcher, the best available current River in California, and the Green and using information on other willow information on the subject suggests Colorado River systems in west-central flycatcher subspecies in evaluating the otherwise. The limited data on willow Utah; E. t. extimus does not occur in listing question for E. t. extimus. In flycatcher wintering habitat indicates Utah, Colorado, or the Carson National applying such information, the Service that this species uses ‘‘* * * brushy Forest in northern New Mexico; the considered ecological similarities and savannah edges and second growth’’ in willow flycatcher is common in the dissimilarities between the subspecies. Costa Rica (Stiles and Skutch 1989); in northern States, Alaska, Canada, most of The Service believes that data from Panama it has been documented in the U.S., Mexico and Panama; caution other subspecies are applicable in some ‘‘shrubby areas’’ (Ridgely 1981); and in should be exercised in defining range cases, but not others. The Service has South America it has been documented limits of the subspecies, including identified which subspecies provided in ‘‘* * * shrubby clearings, pastures, elevational limits. data sources throughout the proposed and lighter woodland’’ or ‘‘* * * on Service Response: Two primary and final rules. The phenomenon of islands with early successional growth’’ authorities (Unitt 1987, Browning 1993) livestock damaging nests and/or (Ridgely and Tudor 1994). Given provide the range limits of E. t. extimus contents through physical contact is existing land use practices in Central identified in this rule (see Figure 1). The known for willow flycatcher subspecies and South America, which are Service also considered other other than E. t. extimus. This threat was characterized by conversion of old- information, such as historical nesting noted to recognize that the potential growth forested habitat to agricultural records, habitat characteristics, and exists, where nests occur low enough in and second-growth habitats, few if any proximity to neighboring populations of vegetation or in other vulnerable of the winter habitat types in which E. t. extimus or other willow flycatcher locations, that livestock, humans, or willow flycatchers have been subspecies. Using this information, the other may contact them or the documented should currently be in Service provisionally defines the nest plant. jeopardy. northwestern limit of the subspecies’ Issue 18: Habitat in California was lost Issue 20: The Service cannot define range to be the Santa Ynez River in to urbanization, not livestock; the nesting habitat; habitat requirements are California. Willow flycatchers nesting proposed rule had inadequate poorly understood; the proposed rule’s along the Santa Ynez River occupy discussion of urban and suburban description of nesting habitat is flawed lowland riparian habitat similar to other development as a threat; urban and inadequate to direct management; coastal California locations of E. t. development is not a threat to some the minimum patch size necessary to extimus, and few willow flycatcher (i.e., populations. support a nesting pair of E. t. extimus E. t. brewsteri) nesting locales are Service Response: Loss and is 1 to 1.5 hectares. known in coastal California for a modification of the riparian habitat of E. Service Response: The Service considerable distance north of the Santa t. extimus is the result of numerous believes the proposed rule and this final Ynez River. factors, discussed in depth in this rule. rule accurately compile and summarize Browning (1993) found no evidence of Not all these factors have affected all the existing information on E. t. extimus intergrades between E. t. extimus and E. riparian habitats, and some rare habitats nesting habitat, and that information is t. adastus in Utah. The northern limit of remain unaffected. Further, the degree sufficient to identify, conserve, and E. t. extimus in Utah is believed to to which these factors influence riparian recover the riparian ecosystem of which correspond closely to the area habitat varies across the landscape. E. t. extimus is a part. Habitat patches comprising the following counties: Urban and suburban development has occupied by E. t. extimus vary Garfield, Kane, San Juan, Washington, certainly impacted some E. t. extimus somewhat in size, floristic composition, and Wayne. This area takes in stretches habitats. These impacts may result from vegetation structure, and type of of riverine riparian habitat in southern direct encroachment and channelization wetland. Therefore, the Service believes Utah that have historical records of of riparian habitats, as in coastal it is inappropriate and inaccurate to Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations 10703 narrowly define suitable habitat in community,’’ which will also benefit E. term habitat losses resulting from terms of plants per unit area, vegetation t. extimus and other riparian and flooding. density, specific plant community aquatic species. The spikedace, loach Issue 24: To manage for E. t. extimus, composition, type and volume of minnow, and E. t. extimus all require the Service will enforce or has proposed surface water, and patch size. The surface water and/or a high water table, a fenced livestock-free corridor. Service has no information to indicate a low to moderate stream gradient, and Service Response: The Service has inaccuracy or inadequacy of the habitat periodic flooding. The fishes neither proposed nor been consulted description presented in this rule. specifically require a ‘‘natural, regarding a fenced, livestock-free Specifically regarding patch sizes, one unregulated hydrograph,’’ which the corridor established along riparian areas to two E. t. extimus pairs have been Service believes would also benefit the on State, Federal, or private lands. observed nesting in habitat patches of flycatcher. These fish also require Issue 25: Beneficial land management 0.5 ha (Sogge et al. 1993, Sogge et al. moderate to high bank stability; practices should be recognized and unpubl. 1994 data); therefore 1.0 to 1.5 maintenance of the riparian vegetation discussed; the proposed rule fails to ha is not an accurate estimate of the on which E. t. extimus depends will acknowledge that some habitats are minimum patch size needed to support provide such bank stability. The Service protected from urban development. a single nesting pair. does not view management for E. t. Service Response: The Service Issue 21: Habitats used by nesting extimus, spikedace, and loach minnow recognizes that some management practices are beneficial. Some practices pairs differ from those used by single, as mutually exclusive, but as mutually have protected or improved habitat, unmated, wandering, or migrant beneficial. flycatchers; the latter face minimal resulted in expanded populations, and/ Issue 23: Floods regenerate habitat, or improved reproduction. The Service threats and are not essential to they do not destroy it; floods destroy conservation of the species. will look to these beneficial land habitat; floods, not livestock, caused management practices as important Service Response: The commenters much of riparian degradation; the provided no data supporting the examples in the recovery planning proposed rule is confusing and process. However, in making a listing statement that habitats used by unpaired contradictory on the role of floods as a E. t. extimus differ from nesting habitat, determination the Service must consider threat or necessary ecological function. and the Service found no indication of the situation across the species’ entire Service Response: The proposed rule this in the available literature. Unmated, range. It is this overall perspective that resident E. t. extimus have been found stated that ‘‘Its habitat rarity, and small, drives the listing decision. Although in habitats identical to nearby habitats isolated populations make the some nesting groups of E. t. extimus occupied by nesting pairs (Sogge and remaining E. t. extimus increasingly may be safe, stable, or perhaps even Tibbitts 1992, Sogge et al. 1993). The susceptible to local extirpation through increasing, the Service has determined Service believes that single, unmated E. stochastic events such as floods * * *. that overall the species is endangered. t. extimus also face threats of habitat In early 1993, catastrophic floods in Issue 26: Existing regulatory loss, and that conservation of these southern California and Arizona mechanisms are adequate, including: individuals is essential to the damaged or destroyed much of the the Migratory Bird Treaty Act (MBTA); conservation of the species, particularly remaining occupied or potential State listings for Arizona, New Mexico, at the low current numbers of breeding habitat. Historically, these and California; section 404 of the Clean flycatchers. floods have always destroyed habitat Water Act; Bureau of Land Management Issue 22: Listing constitutes single- but were also important events in and Forest Service policies; Executive species management that will damage regenerating cottonwood-willow Orders 11988 and 11990; protection of other species; E. t. extimus habitat is communities.’’ riparian habitat due to presence of other incompatible with habitat needs of other It is important to note that E. t. listed species; private and/or listed and sensitive species, particularly extimus is threatened by stochastic cooperative management plans at local the spikedace and loach minnow. events like floods because of its current areas. Service Response: The purposes of the rarity and isolated nature of Service Response: The Service Act are to provide a program for the populations. If the species existed at considered these regulatory mechanisms conservation of threatened and healthy population levels, and if its and management plans, and determines endangered species and to conserve the riparian habitat were not greatly that overall existing regulatory ecosystems upon which threatened and reduced, these natural stochastic events mechanisms are insufficient to conserve endangered species depend. The Service would not constitute threats. The 1993 and recover E. t. extimus in the face of believes that managing for E. t. extimus flood events referred to were the primary threats of loss and and other listed riparian and aquatic extraordinary in nature, described modification of habitat and cowbird species accomplishes this purpose, to regionally as 500-year floods. Therefore, parasitism. A full discussion of Federal the mutual benefit of listed and they do not typify flood events in the and State protection is found in this nonlisted species alike. The intent of river systems involved. Further, while document under Factor D: ‘‘Inadequacy this listing is to conserve and recover E. natural flood events are expected to of existing regulatory mechanisms’’. t. extimus and the riparian and aquatic destroy some flycatcher habitat, they are The Service recognizes that some ecosystems of which it is a part. also crucial for regenerating natural local management plans benefit and The primary constituent elements of riparian nesting habitat. In a healthy conserve E. t. extimus and its habitat. critical habitat described for the system where riparian vegetation is Examples include management of the spikedace (59 FR 10906) and loach abundant and the stream channel is not Bureau of Land Management’s San minnow (59 FR 10898) are not in eroded or destabilized, destruction and Pedro Riparian National Conservation conflict with the habitat requirements regeneration are balanced and habitat is Area (SPRNCA) in Arizona, where six for the southwestern willow flycatcher, generally available. Only when riparian years of livestock exclusion have and are not in conflict with the primary vegetation is severely reduced and the resulted in significant restoration of constituent elements of its proposed stream channel and watershed are riparian habitats and increases in birds critical habitat (58 FR 39495). The fishes destabilized are riparian and aquatic associated with habitats similar to E. t. require ‘‘a healthy, intact riparian species threatened by the natural, short- extimus (Krueper 1993). Willow 10704 Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations flycatchers have not yet returned to institutions have undergone technical species. However, section 2(c) of the Act their historical locations on the review. Other information sources are requires all Federal departments and SPRNCA but may soon. Habitat considered more anecdotal, and the agencies to conserve listed species and protection and cowbird management at Service seeks to confirm such further the purposes of the Act. The Nature Conservancy’s Kern River information before using it. Issue 30: The Service should complete Preserve and on Marine Corps Base Issue 28: The Service should comply a Takings Implications Assessment prior Camp Pendleton in California have with the National Environmental Policy to listing/designating critical habitat. improved habitat and reduced brood Act (NEPA) by completing an Service Response: The Service will parasitism pressures for resident E. t. Environmental Impact Statement (EIS), complete a takings analysis for any final extimus (Griffith and Griffith 1993). and comply with 40 CFR 1506 to reduce designation of critical habitat in Wetland management at Bosque del duplication between NEPA and State compliance with Executive Order 12630 Apache National Wildlife Refuge in and local requirements; the Service and the Attorney General’s New Mexico is apparently sustaining a should comply with 40 CFR 1508.20 to supplemental guidelines issued June 30, small population of flycatchers. While compensate for producing substitute 1988. In accordance with those these actions are beneficial, they resources or environments; the Service guidelines and Interior Department provide for E. t. extimus only at several should engage in joint planning with policy, this analysis will be completed locales. Further, long-term continuation local governments under NEPA after listing, not as part of consideration of these management actions is not regulations. of the listing determination itself. assured. Service Response: As noted in this Issue 31: Requests were received for Provisions of section 404 of the Clean final rule, the Service has determined local public hearings. Water Act do not specifically protect E. that an Environmental Assessment, as Service Response: The proposed rule t. extimus or its habitat, but do provide defined under the authority of NEPA, stated that three public hearings would some protection to the aquatic and need not be prepared for listing actions. be held. Because of many requests for riparian ecosystems of which it is a part. A notice outlining the Service’s reasons additional hearings, a total of six public Section 404 of the Clean Water Act also for this determination was published in hearings were held. Regulations at 50 provides for mitigation of destruction of the Federal Register on October 25, CFR 424.16(c)(3) require the Service to these habitats, however, allowing even 1983 (48 FR 49244). Because of this hold one public hearing if requested. temporary destruction of riparian determination, an EIS also need not be Issue 32: The time allowed for public habitat is not consistent with the prepared. Also because of this comments was inadequate; the proposal immediate conservation needs of E. t. determination, reduction of duplication should have been subjected to peer extimus. between the NEPA process and State review. Issue 27: The Service did not use the and local agencies, and joint planning Service Response: The Service is best available scientific or commercial between those agencies and the NEPA required to accept public comments for information in making this process, are rendered moot. at least 60 days regarding proposals to determination; the Service presented Issue 29: The proposed rule violates list and/or designate critical habitat (50 insufficient and inconclusive the Regulatory Flexibility Act; no CFR 424.16(c)(2)). In this case the information to support listing; the Regulatory Impact Analysis/Assessment Service initially announced a 90-day proposed rule used information which as required under Executive Orders public comment period, then extended was general, incomplete, and originated 12291 and 12866 was completed; it also that another 40 days for a total of 130 with other flycatcher subspecies; the may be inconsistent with the mandates days (July 23, 1993 through November proposed rule was premature; the of other agencies. 30, 1993). Public comment periods and Service did not adequately solicit Service Response: Decisions on listing public hearings are the mechanisms by information and public input; scientific, and reclassification under the Act are which the Service receives input from economic, biological, hydrological and made based on five factors defined in all interested parties, including botanical data must support listing; how section 4(a)(1) of the Act. These five scientific peer review. does the Service know the scientific factors are discussed in this rule, as they Issue 33: Listing would require information supporting listing was relate to E. t. extimus. The Act requires private property owners to consult with right? the Service to consider only scientific the Service on their actions; listing and/ Service Response: The Service and commercial information relating to or designating critical habitat constitute canvassed the published literature these five factors in making listing take of private property rights; adverse regarding the taxonomy, ecology, and determinations, not economic modification of critical habitat would be biology of the southwestern willow information. Economic information is prohibited on private lands; the Service flycatcher, and the threats to it and its considered in designating critical failed to notify the affected public of the habitat. Because numerous and complex habitat, which is not part of this rule. consequences of adverse modification of phenomena and processes were Therefore, compliance with the critical habitat; listing and/or involved, this information ranged from Regulatory Flexibility Act and Executive designating critical habitat may affect general (e.g., wide scale trends in Orders 12291 and 12866 is not an issue civil rights. riparian habitat) to very specific (status for this action, but will be addressed if Service Response: Listing does not of nesting groups). The Service believes a critical habitat designation is made require private property owners to it used the best available information, (H.R. Conf. Rep. No. 835, 97th Cong., 2d consult with the Service on actions and has determined that this Sess. 20 (1982); accord, S. Rep. No. 418, which may affect a listed species. information is adequate to support 97th Cong., 2d Sess. 4 (1982)). However, section 7 of the Act does listing. The Service evaluates sources Where conservation and recovery of require Federal agencies to consult on before using or discounting information. threatened and endangered species is actions which they fund, permit, or In general, the Service expects that inconsistent with other mandates of carry out if those actions may affect a publications in peer-reviewed scientific Federal agencies, processes under listed species or adversely modify journals, reports from land and resource section 7 of the Act serve to evaluate critical habitat. Any potential take of management agencies, and dissertations projects arising from those mandates, private property will be analyzed in or reports from academic or research with regard to protection of listed compliance with Executive Order 12630 Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations 10705

(see Issue 30). As discussed later (Issue of listing. In accordance with section Coordination Act, as amended, and the 35), because critical habitat is not being 4(f)(B) of the Act the recovery plan Migratory Bird Conservation Act, as designated with this rule, comments process will address actions necessary appropriate. The Secretary is regarding critical habitat will be to achieve conservation and recovery of authorized, but not required, to acquire addressed during subsequent actions E. t. extimus, will identify measurable interest in land or water to conserve regarding critical habitat. criteria by which recovery (i.e., the threatened and endangered species. The Issue 34: Requests were received to be point at which protection under the Act Service does not carry out these on a mailing list for all actions relating is no longer necessary) can be gauged, authorities in violation of the U.S. to this issue or to be provided personal and will identify the time and costs Constitution. The Service does not notification of a final decision. required to achieve recovery. The acquire all lands designated as critical Service Response: The Service tries to specific issues identified above will be habitat for a listed species, and does not maintain mailing lists for specific issues considered in developing a recovery develop critical habitat designations whenever possible. However, when plan, and that plan will be available for based on land ownership or interest of large numbers of parties request to be on public review and comment prior to landowners in purchasing or selling such lists, it becomes logistically and adoption. Monitoring species is properties. It is the Service’s policy to financially unfeasible to mail frequently an element of recovery plans, acquire property only on a voluntary information to each party. This issue is and is also required by section 4(g) of basis from willing sellers. one of those, and the Service must rely the Act for any species deemed to be Issue 39: Land use outside occupied/ to some degree on mass communication recovered. critical habitat will be adversely forums like news releases, public Issue 37: Several commenters impacted. notices in newspapers, and publications questioned the motivations of the Service Response: Federal actions that in the Federal Register. petitioners in requesting the listing, and take place outside occupied habitat or Issue 35: Numerous comments were others apparently believed the critical habitat, but that may affect E. t. received regarding critical habitat. petitioners authored the listing extimus, will be subject to consultation Service Response: Critical habitat for proposal. Several commenters noted between the action agency and the E. t. extimus is not being designated that the petition contained inaccuracies, Service in accordance with section 7 of with this rule; therefore, the above and therefore no listing proposal should the Act. Exclusively private actions are issues are not addressed here. have resulted. unaffected by listing and/or designation Designation of critical habitat is being Service Response: The Service cannot of critical habitat, provided they do not deferred while the Service further speak for the petitioners’ motivations in result in violation of section 9 of the Act considers the extent to which requesting listing of E. t. extimus. The (e.g., take of the species). designation is appropriate. Issues Service judged the petition solely on the Issue 40: Listing (regardless of critical pertaining to this designation will be scientific information it contained. habitat) will have adverse impacts on addressed when a final decision is made Inaccuracies were found in the petition, local economy; economic impacts of with regard to the critical habitat but on the whole the Service listing were not addressed; the Act proposal. determined that it presented substantial requires the Service to consider impacts Issue 36: Numerous comments were information indicating that listing may on other wildlife species and social and received regarding recovery of E. t. be warranted. The listing proposal was economic impacts prior to listing. extimus, including: the Service has no authored by the Service, not the Service Response: Consideration of recovery plan for E. t. extimus; the petitioners. The Service developed its economic effects is required for proposed rule failed to identify recovery proposal not from the petition, but from designation of critical habitat. The Act goals for habitat, flycatcher numbers, information gained from journal requires that species listing decisions be and flycatcher distribution; the publications, agency reports, and the based solely on the best scientific and proposed rule failed to identify what general public’s responses to several commercial information available, actions will be used to achieve recovery; information solicitations. This status which precludes consideration of social a recovery plan should address control review process had resulted in the or cultural impacts or impacts on other of cowbird parasitism, nest damage by Service designating E. t. extimus a species. (See section 4(b)(1)(A) of the livestock, tamarisk eradication, category 1 candidate species prior to the Act). The Service anticipates no wintering habitat, monitoring petition being received. That significant impacts on other native populations, protection of public and designation indicated that the Service wildlife species as a result of listing, private lands from fire; cowbird had sufficient information to support a with the probable exception of the parasitism cannot be addressed by listing proposal but did not publish a brown-headed cowbird. listing and designating critical habitat; proposal immediately because it was Issue 41: Who initiated, performed, cowbirds are not easily controlled dealing with listing actions of higher and paid for studies along the Kern without sacrificing flycatchers and/or priority. Information presented by the River? impacting habitat; the proposed rule petitioners that the Service did not Service Response: Reports on studies contained no livestock managing already possess was checked for done on the Kern River were published strategy; rotating livestock will allow accuracy; information that could not be by Harris et al. (1986), Harris et al. habitat enhancement/recovery; the confirmed, or was found to be (1987), Whitfield (1990), and Harris factors affecting riparian habitats are inaccurate, was not used. (1991). Specific information on project numerous and complex; failure to Issue 38: The Service is required to participants, funding sources, and address all could be futile or have purchase interest in land or water for cooperators can be found in those damaging effects. implementation of the Act; this violates sources. The Service understands that Service Response: Section 4(f) of the the U.S. Constitution. monitoring and cowbird control are Act authorizes the Service to develop Service Response: Section 5 of the Act being continued by the Kern River and implement recovery plans for listed directs the Secretary to use land Research Center and The Nature species, not species that are proposed acquisition and other authorities of the Conservancy, with funding assistance for listing. For E. t. extimus, this process Fish and Wildlife Act of 1956, as from the State of California and the therefore begins with the effective date amended, the Fish and Wildlife Service. 10706 Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations

Issue 42: The Service should perform continued existence, and warrants period on the 90-day petition finding additional surveys before listing. listing as endangered. See discussion was insufficient. Service Response: The Service is under Factor A: The present or Service Response: The Service supporting continuing surveys to detect threatened destruction, modification, or acknowledges that its finding on the additional E. t. extimus, to monitor curtailment of its habitat or range. listing petition was published after 90 known nest sites, and to evaluate habitat Issue 46: The ‘‘little’’ willow days, however, the Act (section presence, quality, and distribution. The flycatcher (E. t. brewsteri) is the most 4(b)(3)(A) states that the [Service] shall, Service supports these surveys with common subspecies observed and to the maximum extent practicable, funding to States in accordance with collected in the Southwest. make a petition finding within 90 days section 6 of the Act, and through Service Response: The abundance of (emphasis added). Because the petition logistical and technical assistance to collections of E. t. brewsteri from within was found to present substantial other agencies and parties. Extensive the breeding range of E. t. extimus is information indicating that the surveys in New Mexico and Arizona in because E. t. brewsteri migrates through petitioned action may have been 1993 located E. t. extimus in numbers the Southwest between its Pacific warranted, the Service continued a that do not significantly change the total coastal breeding range and wintering status review after this finding, in population estimates made in the grounds in Central America. E. t. accordance with 50 CFR 424.14(b)(3). proposed rule. These surveys also brewsteri passes through riparian There are no requirements for the confirmed high levels of brood habitats in the breeding range of E. t. Service to open a formal comment parasitism by cowbirds. With low extimus in spring and fall, but does not period regarding a 90-day petition estimates of total flycatcher numbers breed there. finding. The Service did so in this case being validated by continuing surveys, Issue 47: There is no need to list E. to solicit additional information on E. t. the Service has determined that t. extimus in areas where it is doing extimus. In reaching its 12-month sufficient information exists on the well. petition finding, the Service considered threats of habitat loss and cowbird Service Response: The Service has all information received within the 30- parasitism to justify listing. determined that E. t. extimus is day period identified, and information Issue 43: The Service failed to consult endangered; local areas where the bird received for several months thereafter. adequately with private interests, State, is relatively stable could only be Issue 50: E. t. extimus should be listed Federal, and local agencies prior to excluded from listing or classified as as threatened, not endangered. publishing the proposed rule. Service Response: The Service threatened if they constituted distinct Service Response: The Service published public requests for population segments [50 CFR 424.02(k)]. carefully evaluated the status of E. t. information on the status of E. t. extimus The Service has not identified any extimus and has determined that it in the Federal Register when it was distinct population segments of E. t. meets the definition of an endangered designated a category 2 candidate extimus. Further, because the Service species, not a threatened species. As species in January 1989, and when it determines E. t. extimus to be stated in the proposed rule, (58 FR was designated a category 1 species in endangered, all existing habitat and 39495) threatened status would not be November 1991. The Service local nesting concentrations are deemed appropriate because the large historic supplemented these requests with to be essential to the conservation and habitat loss already has caused general mailings soliciting information, recovery of the species. Protection of extirpation throughout a significant and information solicitations in locales where the bird is doing portion of the species’ range. Population professional publications. Beyond these relatively well may be especially numbers are extremely low, and a mechanisms, the Service is constrained important for the conservation and variety of threats are serious and by funding limitations and citizens’ recovery of E. t. extimus. imminent. suits such as Environmental Defense Issue 48: Prey availability may be a Issue 51: Restrictions on rural Center, Inc. vs. Babbitt et al. IV 93– limiting factor. livestock grazing will cause ranching to 1848–R (C.D. Calif.), which was brought Service Response: The Service become nonviable, and the land will be to compel the Service to propose listing recognizes that food availability is converted by suburban development, and designation of critical habitat for always a potential limiting factor in which is a greater threat to E. t. extimus the species, that preclude individually wildlife populations. It is possible that than overgrazing. contacting every interested party. reduction of riparian habitats not only Service Response: The conversion of Issue 44: The parties who petitioned reduced vegetation for nesting, but lands from livestock grazing to suburban for listing should pay for studies reduced or altered the arthropod fauna development is hypothetical and supporting their request. associated with surface water and therefore cannot drive the Service’s Service Response: Regulations extensive vegetation. Also, as noted in determination on this issue. Much of the implementing section 4 of the Act, this rule, some speculation exists that livestock grazing that may be affected by specifically the petition process [50 CFR tamarisk provides a substandard nesting this rule takes place on Federal lands. 424.14], do not require petitioners to habitat because it supports a Therefore, conversion to suburban fund studies supporting their request. significantly different fauna than development would require land Listing determinations are made if native vegetation. However, no exchanges or sales. These actions, if existing information is deemed information was available to evaluate they were determined to affect E. t. sufficient to make a determination. This this factor directly for E. t. extimus. extimus, would require consultation information typically originates from a Issue 49: Several comments were under section 7 of the Act. Regardless, variety of sources. received that pertained to the Service’s prioritization of threats should be Issue 45: The southwestern willow management of the 90-day petition undertaken in the recovery, rather than flycatcher is abundant. There is no need finding, including that the 90-day listing, process. to list. petition finding was late; that it is not Issue 52: The proposed rule fails to Service Response: The Service has the Service’s role to conduct a status consider changing ecological factors: determined that E. t. extimus is rare, not review if information in a petition is drought, migration patterns, nesting abundant, faces serious threats to its lacking; and that a 30-day comment habits, and climatic changes. Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations 10707

Service Response: The Service Service Response: The Service does 1984, Taylor 1986, Unitt 1987, Schlorff recognizes that populations of E. t. not routinely acknowledge receipt of 1990, Ehrlich et al. 1992). extimus are likely to fluctuate naturally each letter commenting on listing Dahl (1990) reviewed estimated losses in response to various ecological factors. proposals. The number of letters in this of wetlands between 1780 and the However, the Service believes that case made it logistically and financially 1980’s in the Southwest: California is declines in habitat availability and impossible to acknowledge each one. estimated to have lost 91 percent, increased exposure to cowbird However, all letters were read, and their Nevada 52 percent, Utah 30 percent, parasitism have caused population issues addressed either here or Arizona 36 percent, New Mexico 33 reductions beyond the scale of natural elsewhere in this final rule. All percent, and Texas 52 percent. As much fluctuations. Fluctuations in response to comment letters and transcripts of as 90 percent of major lowland riparian nonanthropogenic phenomena are likely public hearings are retained in the habitat has been lost or modified in to continue, but the current population permanent file on this species and are Arizona (State of Arizona 1990). levels are so low that these natural available for public inspection. Franzreb (1987) noted that phenomena may be sufficient to cause Issue 57: Protecting flycatcher habitat ‘‘[B]ottomland riparian forests are the local extirpations. may restrict mosquito control, which is most highly modified of natural Issue 53: Restrictions associated with important for control of encephalitis landscapes in California.’’ listing would be in conflict with Kern and other mosquito-borne diseases. Loss and modification of County’s General Plan. Service Response: Where such control southwestern riparian habitats have Service Response: Under section 4 of involves a Federal action, mosquito and occurred from urban and agricultural the Act, the Service considers only disease control actions may be subject to development, water diversion and scientific and commercial information consultation under section 7(a)(2) of the impoundment, channelization, livestock relating to the five listing factors Act, which would evaluate but not grazing, off-road vehicle and other outlined in section 4(a)(1) and discussed necessarily restrict or significantly recreational uses, and hydrological with respect to E. t. extimus in this rule. modify the project. Ultimately, section changes resulting from these and other Therefore, conflicts with local plans 7(e) of the Act allows exemptions to the land uses. Rosenberg et al. (1991) noted requirements of section 7(a)(2). that ‘‘it is the cottonwood-willow plant were not considered in making this community that has declined most with determination. However, the Service Summary of Factors Affecting the modern river management.’’ Loss of the strives to pursue conservation and Species cottonwood-willow riparian forests has recovery of listed species in cooperation After a thorough review and had widespread impact on the with State and local authorities, and consideration of all information distribution and abundance of bird seeks to minimize conflicts. available, the Service has determined species associated with that forest type Issue 54: Listing and critical habitat that the southwestern willow flycatcher (Hunter et al. 1987, Hunter et al. 1988, designations will adversely affect flood should be classified as an endangered Rosenberg et al. 1991). control measures, some authorized by species. Procedures found at section Overuse by livestock has been a major the Federal Emergency Management 4(a)(1) of the Act and regulations factor in the degradation and Agency and other Federal and State implementing the listing provisions of modification of riparian habitats in the regulations; the proposed rule failed to the Act (50 CFR Part 424) were western United States. These effects consider flood accommodation needs, followed. A species may be determined include changes in plant community channelization, and clearing vegetation. to be an endangered or threatened structure and species composition, and Service Response: Flood control species due to one or more of the five relative abundance of species and plant measures virtually always involve a factors described in section 4(a)(1). density. These changes are often linked Federal agency, through funding, These factors and their application to to more widespread changes in permitting, and/or other action. the southwestern willow flycatcher watershed hydrology (Rea 1983, General Therefore, flood control measures that (Empidonax traillii extimus) are as Accounting Office 1988) and directly may affect E. t. extimus would undergo follows: affect the habitat characteristics critical consultation under section 7 of the Act. to E. t. extimus. Livestock grazing in Section 7 and its implementing A. The Present or Threatened riparian habitats typically results in regulations have provisions for Destruction, Modification, or reduction of plant species diversity and emergency consultations, and for Curtailment of its Habitat or Range density, especially of palatable actions within presidentially declared Large scale losses of southwestern broadleaf plants like willows and disaster areas. wetlands have occurred, particularly the cottonwood saplings, and is one of the Issue 55: Government agencies are cottonwood-willow riparian habitats of most common causes of riparian responsible for many impacts to riparian the southwestern willow flycatcher degradation (Carothers 1977, USDA areas; campgrounds, fish hatcheries, and (Phillips et al. 1964, Carothers 1977, Rea Forest Service 1979, Rickard and some district offices are located in 1983, Johnson and Haight 1984, Katibah Cushing 1982, Cannon and Knopf 1984, riparian areas. 1984, Johnson et al. 1987, Unitt 1987, Klebenow and Oakleaf 1984, GAO 1988, Service Response: The Service General Accounting Office (GAO) 1988, Clary and Webster 1989, Schultz and acknowledges that some Federal actions Bowler 1989, Szaro 1989, Dahl 1990, Leininger 1990). are in part responsible for the threats State of Arizona 1990, Howe and Knopf Increases in abundance of riparian facing E. t. extimus. As a result of 1991). Changes in riparian plant bird species have followed reduction, listing, those Federal actions will be communities have resulted in the modification, or removal of cattle subject to consultation under section 7 reduction, degradation, and elimination grazing. Krueper (1993) found the of the Act to evaluate and minimize the of nesting habitat for the willow following increases in birds associated effects of those actions. flycatcher, curtailing the ranges, with cottonwood-willow habitat on Issue 56: The Service does not distributions, and numbers of western Arizona’s San Pedro River four years acknowledge receipt of comments on subspecies, including E. t. extimus after the removal of livestock: yellow listing, and probably does not read (Gaines 1974, Serena 1982, Cannon and warbler, 606 percent; common yellow- them. Knopf 1984, Klebenow and Oakleaf throat, 2,128 percent; yellow-breasted 10708 Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations chat, 423 percent. Bock et al. (1993) exotic tamarisk. Tamarisk (also called tamarisk. In contrast to native found that 40 percent of the riparian saltcedar) was introduced into western phreatophytes, tamarisk does not need bird species they examined, including North America from the Middle East in floods and is intolerant of submersion the willow flycatcher (various the late 1800’s as an ornamental when young. Diversion of water caused subspecies), were negatively affected by windbreak and for erosion control. It the lowering of near-surface livestock grazing. Increases in willow has spread rapidly along southwestern groundwater and reduced the relative flycatcher numbers (various subspecies) watercourses, typically at the expense of success of native species in becoming have followed reduction, modification, native riparian vegetation, especially established. Irrigation water containing or removal of cattle grazing. Taylor cottonwood/willow communities. high levels of dissolved salts also favors (1986) found a negative correlation Although tamarisk is present in nearly tamarisk, which is more tolerant of high between recent cattle grazing and every southwestern riparian salt levels than most native species abundance of numerous riparian birds, community, its dominance varies. It has (Kerpez and Smith 1987, Busch and including the Great Basin willow replaced some communities entirely, Smith 1993). flycatcher (E. t. adastus). In an area but occurs at a low frequency in others. The rapid spread of tamarisk has ungrazed since 1940, his bird counts The spread and persistence of coincided with the decline of the were five to seven times higher than tamarisk has resulted in significant southwestern willow flycatcher. comparable plots where grazing was changes in riparian plant communities. Although E. t. extimus has been terminated in 1980. Taylor and In monotypic tamarisk stands, the most documented nesting in tamarisk, it is Littlefield (1986) found higher numbers striking change is the loss of community not known whether, over the long term, of Great Basin willow flycatchers structure. The multilayered community reproductive success of southwestern correlated with minimal or nonexistent of herbaceous understory, small shrubs, willow flycatchers nesting in tamarisk livestock grazing. Klebenow and Oakleaf middle-layer willows, and overstory has differed from the success of (1984) listed the Great Basin willow deciduous trees is often replaced by one flycatchers nesting in native vegetation. flycatcher among bird species that monotonous layer. Plant species Studies in Arizona have documented declined from abundant to absent in diversity has declined in many areas, low breeding densities and low riparian habitats degraded in part by and relative species abundance has reproductive success for southwestern overgrazing. Schlorff reported willow shifted in others. Other effects include willow flycatchers nesting in tamarisk flycatchers returning to Modoc County, changes in percent cover, total biomass, (Hunter et al. 1988, Muiznieks et al. California, several years after removal of fire cycles, thermal regimes, and 1994). These data, coupled with a livestock grazing (pers. comm. cited in perhaps insect fauna (Kerpez and Smith possible decrease in the arthropod prey Valentine et al. 1988). Knopf et al. 1987, Carothers and Brown 1991, base and thermal protection for nests (1988) found that, during the summer, Rosenberg et al. 1991, Busch and Smith provided by tamarisk, suggest that Great Basin willow flycatchers were 1993). tamarisk may provide poor quality present on winter-grazed pastures, but Disturbance regimes imposed by man nesting habitat. However, more were virtually absent from summer- (e.g., grazing, water diversion, flood extensive comparative studies are grazed pastures. control, woodcutting, and vegetation needed to determine the overall impact The Service believes that clearing) have facilitated the spread of on the southwestern willow flycatcher documentation of livestock impacts on tamarisk (Behle and Higgins 1959, of the conversion of native broadleaf- other willow flycatcher subspecies is Kerpez and Smith 1987, Hunter et al. dominated riparian habitat to tamarisk- relevant to E. t. extimus, because linear 1988, Rosenberg et al. 1991). Cattle find dominated habitat. riparian habitats in the arid range of E. tamarisk unpalatable. However, they eat Other studies of riparian bird t. extimus are especially vulnerable to the shoots and seedlings of cottonwood communities have documented changes fragmentation and destruction by and willow, acting as a selective agent in bird species diversity, corresponding livestock. As shady, cool, wet areas to shift the relative abundance of these with invasion by tamarisk. providing abundant forage, they are species (Kerpez and Smith 1987). Conversion to tamarisk typically disproportionately preferred by Degradation and, in some cases, loss of coincides with reduction or complete livestock over the surrounding xeric native riparian vegetation lowered the loss of bird species strongly associated uplands (Ames 1977, Valentine et al. water table and resulted in the loss of with cottonwood-willow habitats. These 1988, A. Johnson 1989). Harris et al. perennial flows in some streams. With include the yellow-billed cuckoo (1987) believed that termination of its deep root system and adaptive (Coccyzus americanus), summer tanager grazing along portions of the South Fork reproductive strategy, tamarisk thrives (Piranga rubra), northern oriole (Icterus of the Kern River in California was or persists where surface flow has been galbula), and the southwestern willow responsible for increases in riparian reduced or lost. Further, tamarisk flycatcher (Hunter et al. 1987, Hunter et vegetation and, consequently, nesting E. establishment often results in a self- al. 1988, Rosenberg et al. 1991). While t. extimus. Suckling et al. (1992) noted perpetuating regime of periodic fires, Brown and Trosset (1989) believed that most of the areas still known to which were uncommon in native tamarisk may serve as an ‘‘ecological support E. t. extimus have low or riparian woodlands (Busch and Smith equivalent’’ to native vegetation, they nonexistent levels of livestock grazing. 1993). noted that their study occurred where a More recent surveys (Muiznieks et al. Manipulation of perennial rivers and tamarisk community became established 1994) have found E. t. extimus in areas streams has resulted in habitats that where no native equivalent existed with livestock grazing; however, these tend to allow tamarisk to outcompete before. occur in widely dispersed, small groups native vegetation. Construction of dams Some authors believe tamarisk may whose nesting success is largely created impoundments that destroyed not provide the thermal protection that unknown, and where livestock grazing native riparian communities. Dams also native broadleaf species do (Hunter et intensity and seasonality are also eliminated or changed flood regimes, al. 1987, Hunter et al. 1988). This could unknown. which were essential in maintaining be important at lower elevations in the Another likely factor in the loss and native riparian ecosystems. Changing Southwest, where extreme high modification of southwestern willow (usually eliminating) flood regimes temperatures are common during the flycatcher habitat is invasion by the provided a competitive edge to bird’s midsummer breeding season. It is Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations 10709 also possible that tamarisk affects E. t. vegetation are likely. Channelization where cowbird numbers have also been extimus by altering the riparian insect often alters stream banks and fluvial reduced by trapping (Griffith and fauna (Carothers and Brown 1991). dynamics necessary to maintain native Griffith 1993). Approximately eight Some sources also speculated that nests riparian vegetation. other nesting groups are known in in tamarisk stands may be more easily Suckling et al. (1992) suggested that southern California, all of which located by brown-headed cowbirds (see logging in the upper watersheds of consisted of six or fewer nesting pairs in cowbird discussion below). Hunter et al. southwestern rivers may constitute recent years (Unitt 1987, Schlorff 1990, (1987) reported the willow flycatcher as another potential threat to the Service, unpubl. data). Using the most one of seven midsummer-breeding southwestern willow flycatcher. They recent information for all areas, builders of open nests that were found stated that logging increases the approximately 70 pairs and 8 single in tamarisk at higher elevations but not likelihood of damaging floods in southwestern willow flycatchers are lower elevations. Nesting E. t. extimus southwestern willow flycatcher nesting known to exist in California. Where have been found in tamarisk at middle habitat. information on population trends since elevations (610–1200 m (2000–3500 Finally, the willow flycatcher (all the mid-1980’s is available, most areas feet)) (Hundertmark 1978, Hubbard subspecies) is listed among neotropical show declines. Three recent status 1987, Hunter et al. 1987, Brown 1988, migratory birds that may be impacted by reviews considered extirpation from Sogge et al. 1993, Muiznieks et al. alteration of wintering habitat, as California to be possible, even likely, in 1994). However, nest success in through tropical deforestation (Finch the foreseeable future (Garrett and Dunn tamarisk at these elevations appears to 1991, Sherry and Holmes 1993). 1981, Harris et al. 1986, Schlorff 1990). be low (Sogge and Tibbitts 1992, Sogge Population Trends for Each State Are The State of California classifies the et al. 1993, Muiznieks et al. 1994). The Discussed Briefly Below willow flycatcher as endangered species is essentially absent from [California Department of Fish and tamarisk-dominated habitats below 610 California. All three resident Game (CDFG) 1992]. m (2000 feet). On the lower Colorado subspecies of the willow flycatcher (E. Arizona. Records indicate that the River (approximately 25 m (80 feet)) t. extimus, E. t. brewsteri, and E. t. former range of the southwestern willow where tamarisk is widely dominant, the adastus) were once considered widely flycatcher in Arizona included portions only territories found in recent decades distributed and common in California, of all major watersheds (Colorado, Salt, were in relict stands dominated by wherever suitable habitat existed Verde, Gila, Santa Cruz, and San Pedro). willow, cottonwood, and other native (Wheelock 1912, Willett 1912, Grinnell Historical records exist from the vegetation (Muiznieks et al. 1994). Unitt and Miller 1944). The historic range of Colorado River near Lee’s Ferry and (1987) speculated that at higher E. t. extimus in California apparently near the Little Colorado River elevations and in the eastern portion of included all lowland riparian areas of confluence (Phillips, pers. comm., cited its range, some E. t. extimus populations the southern third of the State. Unitt in Unitt 1987), and along the Arizona- may be adapting to tamarisk. (1984, 1987) concluded that it was once California border (Phillips 1948, Unitt Water developments also likely fairly common in the Los Angeles basin, 1987), the Santa Cruz River near Tucson reduced and modified southwestern the San Bernardino/Riverside area, and (Swarth 1914, Phillips 1948), the Verde willow flycatcher habitat. The series of San Diego County. Willett (1912, 1933) River at Camp Verde (Phillips 1948), the dams along most major southwestern considered the bird to be a common Gila River at Fort Thomas (W.C. Hunter, rivers (Colorado, Gila, Salt, Verde, Rio breeder in coastal southern California. pers. comm., cited in Unitt 1987), the Grande, Kern, San Diegito, and Mojave) Nest and egg collections indicate the White River at Whiteriver, the upper have altered riparian habitats bird was a common breeder along the and lower San Pedro River (Willard downstream of dams through lower Colorado River near Yuma in 1912, Phillips 1948), and the Little hydrological changes, vegetational 1902 (T. Huels, University of Arizona in Colorado River headwaters area changes, and inundated habitats litt., transcripts of H. Brown’s field (Phillips 1948). upstream. New habitat is sometimes notes). The southwestern willow flycatcher created along the shoreline of reservoirs, All three willow flycatcher subspecies has declined throughout Arizona. The but this habitat (often tamarisk) is often breeding in California have declined, subspecies was apparently abundant on unstable because of fluctuating levels of with declines most critical in E. t. the lower Colorado River in 1902 (T. regulated reservoirs (Grinnell 1914, extimus, which remains only in small, Huels in litt., transcripts of H. Brown’s Phillips et al. 1964, Rosenberg et al. disjunct nesting groups (Unitt 1984 and field notes), but only four to five 1991). Construction of Glen Canyon 1987, Gaines 1988, Schlorff 1990, territories were located in 1993 Dam on the Colorado River allowed Service unpubl. data). Only two nesting (Muiznieks et al. 1994). Elsewhere in establishment of a tamarisk riparian groups have been stable or increasing in the State, E. t. extimus persists only in community downstream in the Grand recent years. One is on private land several small, widely scattered Canyon, where a small population of E. where habitat impacts from livestock locations. In the Grand Canyon, several t. extimus exists, with poor grazing have been virtually eliminated groups of nesting birds have fluctuated reproduction (Brown 1991, Sogge et al. (Harris et al. 1987, Whitfield 1990). This from a high of 11 singing males in 1986 1993). However, Lake Powell, formed group on the South Fork of the Kern (Brown 1988) to two pairs and three upstream of the dam, inundated what River experienced numerical declines in single birds in 1992 (Sogge and Tibbitts was apparently superior habitat, with E. 1991 and 1992, but increases in nesting 1992). Grand Canyon surveys in 1993 t. extimus considered common (Behle success were realized in 1992 and 1993, located 13 birds; six unpaired and Higgins 1959). attributed to shaking (killing) or individuals, two pairs, and what Diversion and channelization of removing cowbird eggs or nestlings appeared to be one male with two natural watercourses are also likely to found in flycatcher nests, and trapping females. No nesting attempts were have reduced E. t. extimus habitat. cowbirds (Whitfield and Laymon, Kern successful (Sogge et al. 1993). Although Diversion results in diminished surface River Research Center, in litt. 1993). The Brown (et al. 1987) noted E. t. extimus flows and increased salinity of residual other apparently stable nesting group is as nesting in Havasu Canyon, in 1993 flows. Consequent reductions and along the on none were located there and cowbirds composition changes in riparian Marine Corps Base Camp Pendleton, were abundant (Sogge et al. 1993). A 10710 Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations location on the lower San Pedro River State of Arizona classifies the willow flycatcher was located near Espanola apparently supported relatively large flycatcher as endangered (AGFD 1988). (Leal, Meyer and Thompson, unpubl. numbers of E. t. extimus in the 1940’s New Mexico. Bailey (1928) classified data). In 1993, surveys of 52 locations (G. Monson, private individual, in litt. breeding willow flycatchers in New found 31 pairs or singing males at 15 of 1993 and pers. comm. 1993), but only a Mexico as E. t. brewsteri, according to those locations (S.O. Williams III, New single pair in 1978 and 1979, and none Oberholser’s (1918) taxonomy of that Mexico Department of Game and Fish in 1986 (Unitt 1987). Following habitat time. Because of few records at that (NMDGF), in litt. 1993). Hubbard (1987) improvements at this locale, six to seven time, she believed that either the bird estimated that the State population may singing males were present in 1993, and was rare or was overlooked by most total 100 pairs; that estimate has not a total of 11 singing males were located observers and collectors. More recently, been revised. Hubbard (1987) found that at two other locations on the lower San Hubbard (1987) reviewed and ‘‘the conclusion is virtually inescapable Pedro in 1993 (Muiznieks et al. 1994). summarized the flycatcher’s status in ** * a decrease has occurred in the Historically occupied habitat on the New Mexico. He classified breeding population of breeding willow upper San Pedro River is in the process birds in the State as E. t. extimus and flycatchers in New Mexico over historic of rehabilitation, but remains reported breeding locations that were time,’’ resulting from habitat loss. The unoccupied by nesting E. t. extimus generally confined to the regions west of State of New Mexico classifies the (Krueper and Corman 1988, D. Krueper the Rio Grande, with records from the willow flycatcher as endangered unpubl. data). Two small groups at high Rio Grande, Chama, Zuni, San (NMDGF 1988). elevations in the White Mountains, Francisco, and Gila drainages (See also Texas. The eastern limit of the comprising approximately five singing Hubbard 1982). However, he southwestern willow flycatcher’s males each, have remained relatively provisionally assigned all willow breeding range is in western Texas stable numerically from 1985 to 1993 flycatchers nesting in New Mexico to E. (Unitt 1987). Collections have been (Muiznieks et al. 1994, Arizona Game t. extimus, noting records from the made at Fort Hancock on the Rio Grande and Fish Department (AGFD), unpubl. Pecos River and Penasco Creek in the (Phillips 1948), in the Guadalupe data). At a site on the Verde River in southeast and from near Las Vegas in Mountains (Phillips, pers. comm., cited central Arizona where R. Ohmart the northeast. in Unitt 1987), the Davis Mountains Both Hubbard (1987) and Unitt (1987) (unpubl. data) observed four nesting (Oberholser 1974), and from unspecified believed that the overall range of E. t. pairs in 1992, one pair and one single locales in Brewster County (Wolfe extimus had not been reduced in New male were present in 1993. The single 1956). Wauer (1973 and 1985) Mexico, but that habitat and numbers nest produced only a cowbird young. Of considered E. t. extimus a rare summer had declined. Unitt (1987) believed the 13 river reaches in Arizona studied by resident in Big Bend National Park. Data majority of all remaining nesting birds are lacking on current population levels Hunter et al. (1987), nesting E. t. may occur in New Mexico. Areas with and trends in Texas. Loss and extimus were extirpated from eight, 19 and 53 singing flycatchers, not modification of habitat may have declining in two, and present in stable distinguished as nesting or migrants, reduced populations on the Rio Grande numbers in three. were found on the upper Gila River and Pecos Rivers. Statewide surveys in 1993 located (Montgomery et al. 1985, cited in Utah. The north-central limit of between 42 and 56 territorial males, and Suckling et al. 1992). Preliminary data breeding southwestern willow all nest sites were considered vulnerable from 1994 surveys indicate that this flycatchers is in southern Utah. Behle to habitat loss and cowbird parasitism breeding group is still present. However, (1985) and Unitt (1987) believed a clinal (Muiznieks et al. 1994). Preliminary the breeding status of flycatchers and gradation between E. t. extimus and E. data from 1994 surveys indicate that trend over time have not been t. adastus existed, but Browning (1993) approximately 70 to 80 breeding pairs determined (S.O. Williams, New Mexico disagreed, identifying a range boundary were found at a total of 12 locations in Department of Game and Fish—pers. at approximately the 38th north parallel. the State. This included the discovery of comm.) Southern Utah is characterized by a group of flycatchers at one location Hubbard (1987) noted that data were extreme topographic relief. In this consisting of approximately 15 breeding lacking for trends of most nesting areas. region, subspecific separation may be a pairs. Brood parasitism by cowbirds was However, where data were available, function of elevation, with E. t. extimus documented at at least six (50%) of they indicated loss of a group of 15 at lower elevations (e.g., Virgin and those 12 sites. Brown-headed cowbirds breeding pairs by the rising waters of Colorado Rivers) and E. t. adastus were documented at all 12 breeding Elephant Butte Reservoir. The willow higher (e.g., Sevier River, wet meadows locations (Arizona Game and Fish flycatcher was considered fairly of mountains and high plateaus). Department, in prep.). common in this area on the middle Rio Records that are likely to represent E. t. Where information on population Grande in the late 1970’s (Hundertmark extimus are from the Virgin River trends since the mid-1980’s is available, 1978). Hubbard hypothesized that some (Phillips 1948, Wauer and Carter 1965, most areas show declines and/or high of these birds could have moved Whitmore 1975), Kanab Creek, and rates of cowbird parasitism. In early upstream, to new shoreline habitat along the San Juan and Colorado Rivers 1993, catastrophic flooding on the created by the impoundment. Between (Behle et al. 1958, cited in Unitt 1987; Verde, Gila, and San Pedro Rivers 1987 and 1990, bird surveys along the Behle and Higgins 1959, Behle 1985; see temporarily damaged many sites Rio Grande Valley State Park in also Browning 1993). Other reports inhabited since the mid-1980’s, and Albuquerque found a single singing document the subspecies being present much potential habitat. Unitt (1987) willow flycatcher during the breeding along the Virgin, Colorado, San Juan, concluded that ‘‘Probably the steepest season (Hoffman 1990). Current trends and perhaps Paria Rivers (BLM, unpubl. decline in the population levels of E. t. in New Mexico are not being data). Although Behle believed E. t. extimus has occurred in Arizona * ** extensively monitored. However, in extimus was always rare in southern E. t. extimus has been extirpated from 1992, 71 transects along the Rio Grande Utah overall (pers. comm. cited in Unitt much of the area from which it was were surveyed for breeding birds, but 1987), he considered it a locally originally described, the riparian not specifically targeting willow common breeding resident where woodlands of southern Arizona.’’ The flycatcher habitat. A single willow habitat existed along the Colorado River Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations 10711 and its tributaries in southeastern Utah nesting pairs. Unitt (1987) believed the beyond existing regulations on capture, (Behle and Higgins 1959). total was ‘‘well under’’ 1000 pairs, more handling, transportation, and take of Few data are available on population likely 500. The regional estimates and native wildlife. The California trends in southern Utah. However, loss information on which these total Endangered Species Act (CESA) and modification of habitat is likely to estimates are based generally date from prohibits unpermitted possession, have reduced populations on the Virgin, the late 1980’s to 1993 (e.g., Hubbard purchase, sale, or take of listed species. Colorado, and San Juan Rivers. These 1987, T. Johnson 1989). Virtually all However, the CESA definition of take losses have been due to suburban nesting groups monitored since that does not include harm, which under the expansion and habitat changes along the time have continued to decline Act can include destruction of habitat Virgin River, inundation by Lake Powell (Whitfield 1990, Brown 1991, Sogge et that actually kills or injures wildlife by on the Colorado and San Juan Rivers, al. 1993, Whitfield and Laymon, significantly impairing essential and encroachment of tamarisk unpubl. data). behavioral patterns (50 CFR 17.3). throughout the region (Unitt 1987, BLM However, CESA requires consultation unpublished data). B. Overutilization for Commercial, between the CDFG and other State Nevada. Unitt (1987) reported only Recreational, Scientific, or Educational agencies to ensure that activities of State three records for Nevada, all made Purposes agencies will not jeopardize the before 1962. Unitt (1987), Hubbard The Service is unaware of threats continued existence of State-listed (1987), and Browning (1993) all resulting from overutilization. species (E. Toffoli, State of California, in considered southern Nevada C. Disease or Predation litt. 1992). The Service believes that this (approximately south of 38° north and other regulatory mechanisms are parallel) to be within the range of E. t. The Service is unaware of any disease inadequate to ensure the continued extimus. However, no recent data are that constitutes a significant threat to E. existence of the southwestern willow available on population levels or trends. t. extimus. Boland et al. (1989) found flycatcher. Habitat may remain along the lower only one case of larval parasites in Virgin River and at the inflow of the willow flycatcher nestlings in E. Other Natural or Manmade Factors Virgin River into Lake Mead. However, California. Affecting Its Continued Existence loss and modification of habitat is likely Predation of southwestern willow The riparian habitat of the to have reduced populations on the flycatchers may constitute a significant southwestern willow flycatcher has Virgin and Colorado Rivers. threat and may be increasing with always been rare and has become more Colorado. Whether or not the habitat fragmentation. Where E. t. so. Its habitat rarity and small, isolated southwestern willow flycatcher breeds extimus has been extirpated in the lower populations make the remaining E. t. in Colorado is unclear. Hubbard (1987) Colorado River valley, Rosenberg et al. extimus increasingly susceptible to local believed the subspecies ranged into (1991) found increases in the great- extirpation through stochastic events extreme southwestern Colorado, tailed grackle (Quiscalus mexicanus), such as floods, fire, brood parasitism, Browning (1993) was noncommittal, which preys on the eggs and young of predation, depredation, and land and Unitt (1987) tentatively used the other birds (Bent 1965). Whitfield (1990) development. In early 1993, New Mexico-Colorado border as the found predation on E. t. extimus nests catastrophic floods in southern boundary between E. t. extimus and E. to be significant. Predation increased California and Arizona impacted much t. adastus. Several specimens taken in with decreasing distance from nests to of the remaining occupied or potential late summer have been identified as E. thicket edges, suggesting that habitat breeding habitat. Historically, these t. extimus, but nesting was not fragmentation may increase the threat of floods have always destroyed habitat confirmed (Bailey and Niedrach 1965). predation. but were also important events in Phillips (1948) cautioned that willow regenerating cottonwood-willow flycatchers in this region displayed D. The Inadequacy of Existing communities. However, with little considerable individual variation and Regulatory Mechanisms southwestern willow flycatcher habitat may represent intergrades between E. t. The Migratory Bird Treaty Act remaining, widespread events like those extimus and E. t. adastus. No recent (MBTA)(16 U.S.C. § 703–712) is the only of 1993 could destroy virtually all data are available on occurrence, current Federal protection provided for remaining habitat throughout all or a population levels, or trends in this area. the southwestern willow flycatcher. The significant portion of the subspecies’ Mexico. Six specimens from Baja MBTA prohibits ‘‘take’’ of any migratory range. Further, regeneration with California del Norte and two from bird, which is defined as: ‘‘* * * to natural vegetation after floods may be Sonora were discussed by Unitt (1987). pursue, hunt, shoot, wound, kill, trap, inhibited if the area is subjected to He and Phillips (pers. comm., cited in capture, or collect, or attempt to pursue, overgrazing by domestic livestock. Unitt 1987) believed E. t. extimus was hunt, shoot, wound, kill, trap, capture, The disjunct nature of habitats and not common in northwestern Mexico. or collect * * *’’ However, unlike the small breeding populations impede the Wilbur (1987) was skeptical of its Act, there are no provisions in the flow of genetic material and reduce the presence as a breeder in Baja California. MBTA preventing habitat destruction chance of demographic rescue from In the more general treatments of field unless direct mortality or destruction of migration from adjacent populations. guides, the willow flycatcher is active nests occurs. The resulting constraints on the gene described as breeding in extreme The majority of the southwestern pool intensify the external threats to the northwestern Mexico, including willow flycatcher’s range lies within species. northern Baja California del Norte California, Arizona, and New Mexico Brood parasitism by the brown- (Blake 1953, Peterson 1973). No recent (Phillips 1948, Hubbard 1987, Unitt headed cowbird also threatens the data are available on current population 1987). All of those States classify the southwestern willow flycatcher. levels or trends. willow flycatcher as endangered (AGFD Cowbirds lay their eggs in the nests of Using the most recent censuses and 1988, NMDGF 1988, CDFG 1992). The other, usually smaller, songbirds. The estimates for all areas, the estimated State listings in New Mexico and cowbird often removes a number of the total of all southwestern willow Arizona do not convey habitat host’s eggs and replaces them with an flycatchers is approximately 300 to 500 protection or protection of individuals equal number of cowbird eggs. The host 10712 Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations species then incubates the cowbird eggs, extimus, by brown-headed cowbirds is and E. alnorum in marshy habitats in which typically hatch prior to the host’s well documented (Hanna 1928, Rowley the upper Midwest, where parasitism own eggs. Cowbird eggs require a 1930, Willett 1933, Hicks 1934, King rates ranged from 3 percent to 19 relatively short incubation period of 10 1954, Holcomb 1972, Friedmann et al. percent. However, perhaps reflecting his to 12 days. Thus, the young cowbirds 1977, Garret and Dunn 1981, Harris et regional perspective, he characterized have several advantages over the host’s al. 1987, Brown 1988, 1991, Sedgewick the high parasitism rates on willow young; they hatch earlier, they are and Knopf 1988, Whitfield 1990, Harris flycatchers reported by Trautman (1940, larger, and they are also more aggressive 1991, Sogge et al. 1993, Muiznieks et al. cited in McCabe 1991) and Sedgwick than the host’s young. Cowbird 1994). and Knopf (1988) as aberrant (56 nestlings typically outcompete those of The increases in cowbirds in the percent and 41 percent, respectively). the host species for parental care, and, Southwest and parasitism of E. t. McCabe considered the high rates the as a result, the host species’ own extimus and other birds are generally result of the ‘‘* * * linear configuration reproduction is reduced or eliminated attributed to the following scenario: The of the habitat * * * [c]owbirds lay eggs (Bent 1965, McGeen 1972, Mayfield introduction of modern human in songbird nests closest to cover edge.’’ 1977a, Harrison 1979, Brittingham and settlements, livestock grazing, and other The vast majority of southwestern Temple 1983). agricultural developments resulted in willow flycatcher habitat is very linear The brown-headed cowbird habitat fragmentation. Simultaneously, and may experience higher rates of commonly preys on insects stirred up livestock grazing and other agricultural parasitism than other willow flycatcher by grazing ungulates, and was originally developments served as vectors for subspecies. restricted to the Great Plains, where it cowbirds by providing feeding areas Brittingham and Temple (1983) was strongly associated with American near host species’ nesting habitats considered ‘‘high’’ parasitism rates bison (Bison bison). As North America (Hanna 1928, Gaines 1974, Mayfield (percent of nests parasitized) to be 24 was settled, cowbirds became associated 1977a). Cowbirds may travel almost 7 percent, with some as high as 72 with livestock and human agriculture kilometers (4.2 miles) from feeding sites percent. Mayfield (1977a) thought a because of the food sources they where livestock congregate to areas species (or population) might be able to provided (Bent 1965, Flett and Sanders where host species are parasitized survive a 24 percent parasitism rate, but 1987, Valentine et al. 1988). The (Rothstein et al. 1984). These factors that losses much higher than that expansion of agriculture, livestock increased both the vulnerability of E. t. ‘‘would be alarming.’’ Parasitism rates of grazing, and wide scale human activities extimus and the likelihood of 72 percent to 83 percent on Kirtland’s in general caused opening and encounters with cowbirds. Finally, the warbler (Mayfield 1977b) resulted in a fragmenting of forest and woodland high edge-to-interior ratio of linear precipitous population decline. Where habitats. Habitat fragmentation and riparian habitats like those used by E. t. parasitism rates are known for E. t. agriculture are strongly correlated with extimus renders birds nesting there extimus, they are comparable to rates for increased rates of brood parasitism by particularly vulnerable to parasitism Kirtland’s warbler and are capable of brown-headed cowbirds (Rothstein et al. (Airola 1986, Laymon 1987, Harris causing similar declines. In California, 1980, Brittingham and Temple 1983, 1991). Linear riparian habitats are also parasitism rates ranged from 50 percent Airola 1986, Robinson et al. 1993). especially vulnerable to fragmentation to 80 percent between 1987 and 1992, Some species are likely to have adapted by grazing, which further increases both when an estimated population size to parasitism over time, particularly the edge-to-interior ratio and the threat decreased from 44 to 28 nesting pairs prairie nesters in the original range of of parasitism. (Whitfield 1990, Harris et al. 1991, the cowbird. However, the cowbird’s The effects of parasitism by brown- Whitfield and Laymon, unpubl. data). rapid expansion now brings it into headed cowbirds on willow flycatchers These parasitism rates were considered contact with forest and woodland include reducing nest success rate and minimum measures, because several species not adapted to deal with brood egg-to-fledging rate, and delaying nests were abandoned each year due to parasitism, significantly impacting those successful fledging (because of renesting unknown causes, which could have species (Hill 1976, Mayfield 1977a, attempts) (Harris 1991). A common been parasitism. Brown (1988) reported Robinson et al. 1993). response to parasitism is abandonment an average 50 percent parasitism rate in The brown-headed cowbird was of the nest (Holcomb 1972). Willow the Grand Canyon between 1982 and apparently an uncommon bird within flycatchers may also respond to 1987. Although his estimated the range of E. t. extimus, until the late parasitism by ejecting cowbird eggs, by population increased from two pairs to 1800’s. Since then, the species has burying them with nesting material and 11 during that period, it has since greatly expanded in numbers and renesting on top of them, or by renesting decreased back as low as two nesting distribution throughout the region in another nest (Harris et al. 1991). pairs (Brown 1991, Sogge and Tibbitts (Laymon 1987, Rothstein in prep.). However, the success rate of renesting is 1992). In 1993, parasitism reached 100 Increases in cowbirds in the San often reduced, because these attempts percent in the Grand Canyon, and no E. Bernardino Valley between 1918 and produce fledglings several weeks later t. extimus were fledged (Sogge et al. 1928 caused Hanna (1928) than normal, which may not allow them 1993). Harris et al. (1991) believed that ‘‘considerable alarm.’’ Although adequate time to prepare for migration the parasitism rates observed on the Friedmann et al. (1977) reported (Harris 1991). Renesting also usually Kern River in 1987 (68 percent of all relatively low rates of parasitism of consists of smaller clutches, further nests, 88 percent of all nest territories) willow flycatchers in the western reducing overall reproductive potential were high enough to prevent E. t. United States, this was apparently (Holcomb 1974). extimus from recolonizing lowland owing to their data (egg sets) being McCabe (1991) downplayed the riparian habitat, even if it were restored. collected prior to the major incursions significance of cowbird parasitism as a Rothstein et al. (1980), Stafford and of cowbirds into Pacific coast riparian threat to any species except Kirtland’s Valentine (1985), and Harris (1991) habitats (L. Kiff, Western Foundation for warbler (Dendroica kirtlandii). believed parasitism may be correlated Vertebrate Zoology, in litt. 1993). Brood McCabe’s monograph focussed on the with elevation, being more severe at parasitism of several subspecies of the combined ‘‘Traill’s flycatcher’’ lower elevations. Coupled with greater willow flycatcher, including E. t. superspecies, comprised of E. t. traillii loss of lowland (desert) riparian habitat, Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations 10713 the effects of habitat loss and parasitism The Service has carefully assessed the State agencies recommended substantial are compounded. However, cowbirds best scientific and commercial changes in proposed critical habitat now appear to be increasing at higher information available regarding the past, areas. elevations (Hanka 1985). present, and future threats faced by this The Service is presently reconsidering In addition to causing habitat species in determining to make this rule the prudence of critical habitat degradation and facilitating brood final. Based on this evaluation, the designation for this species, the need for parasitism, livestock grazing in and near preferred action is to list the special management considerations or riparian areas may also threaten E. t. southwestern willow flycatcher as protection of habitat within the species’ extimus through direct mortality. endangered. A decision regarding range, and the proper boundaries of any Livestock in riparian habitats sometimes designation of critical habitat for this areas that might be designated as critical make physical contact with nests or species is being deferred, and a final habitat. Issues raised in public supporting branches, resulting in decision regarding the designation will comments, new information, and the destruction of nests and spillage of eggs be made by July 23, 1995. Critical lack of the economic information or nestlings. All known documentation habitat for this species is not now necessary to perform the required of this threat involves E. t. brewsteri, determinable. economic analysis cause the Service to conclude that critical habitat is not now perhaps because virtually all known Critical Habitat remaining populations of E. t. extimus determinable and to invoke an are in ungrazed habitats (Serena 1982, Critical Habitat is defined in section extension until July 23, 1995, pursuant Harris et al. 1987, Whitfield and 3 of the Act as (i) the specific areas to 16 U.S.C. § 1533(b)(6)(C) for reaching Laymon, unpubl. data). Valentine et al. within the area occupied by a species, a final decision on the proposal of (1988) studied willow flycatchers in at the time it is listed in accordance critical habitat for the flycatcher. The with the Act, on which are found those California from 1983 through 1987, Service has determined that this is in physical or biological features (I) when 11 of their 20 recorded nesting compliance with provisions of 50 CFR essential to the conservation of the attempts failed. They found that ‘‘Prior 424.12(a) and § 424.17, regarding species and (II) that may require special to reduction of grazing intensity in delaying final rules on proposed critical management considerations or 1987, livestock accounted for 36 percent habitat designations, and with protection and; (ii) specific areas of the failed nests or 20 percent of all provisions for addressing State agencies outside the geographical area occupied nesting attempts. In addition, livestock that disagree in whole or part with a by a species at the time it is listed, upon destroyed four successful nests shortly proposed rule (50 CFR 424.18(c)). In a determination that such areas are after the young had fledged.’’ Stafford order to assist in its deliberation, the essential for the conservation of the and Valentine (1985) reported that three Service is reopening comment on the species. ‘‘Conservation’’ means the use proposal to designate critical habitat for of eight (37.5 percent) willow flycatcher of all methods and procedures needed nests in their study site were probably a period of 60 days. Comments are to bring the species to a point at which particularly sought on the following destroyed by cattle. Flett and Sanders listing under the Act is no longer (1987) documented no nest upsets due topics: necessary. 1. The need for special management to livestock but noted the vulnerability Section 4(a)(3) of the Act and of nests to upset, due to their placement of areas within the range of the implementing regulations (50 CFR flycatcher, including those proposed as low in willow clumps (see also Serena 424.12) require that, to the maximum 1982). Livestock grazing may affect E. t. critical habitat as well as other areas, extent prudent and determinable, the 2. The net benefit to the flycatcher in extimus similarly. Secretary designate critical habitat at the addition to the protection provided by The southwestern willow flycatcher’s time a species is determined to be its listing as endangered likely to accrue preference for, and former abundance endangered or threatened. Critical from a designation of critical habitat, in, floodplain areas that are now largely habitat was proposed to be designated and agricultural may indicate a potential for the flycatcher at the time it was 3. Any indication that areas should be threat from pesticides. Where flycatcher proposed for listing as endangered to added to or excluded from those populations remain, they are sometimes encompass approximately 640 miles proposed for designation. in proximity to agricultural areas, with (1000 km) of riparian zones in the States Comments already received that the associated pesticides and herbicides. of California, Arizona, and New Mexico. address the above topics will be Without appropriate precautions, these After reviewing comments submitted considered in reaching a final decision agents may potentially affect the during the public comment period the regarding critical habitat designation, southwestern willow flycatcher through Service is deferring the designation of and need not be resubmitted. direct toxicity or effects on their insect critical habitat for this endangered food base. No quantitative data on this species. The Service received numerous Available Conservation Measures potential threat are known at this time. comments on the proposed rule, Conservation measures provided to Recreation that is focused on riparian including many recommendations for species listed as endangered or areas, particularly during warm summer additions and deletions to proposed threatened under the Act include breeding months, may also constitute a critical habitat. The Service is reviewing recognition, recovery actions, threat to E. t. extimus. Taylor (1986) these comments as well as survey data requirements for Federal protection, and found a possible correlation between collected in 1994. These sources prohibitions against certain practices. recreational activities and decreased included more complete information on Recognition through listing encourages riparian bird abundance. Blakesley and the primary constituent elements of and results in conservation actions by Reese (1988) reported the willow flycatcher habitat and on the Federal, State, and local agencies, flycatcher (probably E. t. adastus) as one distribution of that habitat across the private organizations, and individuals. of seven species negatively associated bird’s range. Substantial disagreement The Act provides for possible land with campgrounds in riparian areas in has also been found among scientists acquisition and cooperation with the northern Utah. It is unknown whether knowledgeable about the species States and requires that recovery actions these possible effects involve impacts to regarding the proposed designations. be carried out for all listed species. The habitat or disturbance of nesting birds. Further, written comments submitted by protection required of Federal agencies 10714 Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations and the prohibitions against taking and The Act and implementing riparian habitat or the disturbance of harm are discussed, in part, below. regulations found at 50 CFR 17.21 set breeding flycatchers. Section 7(a) of the Act, as amended, forth a series of general prohibitions and Activities that the Service believes requires Federal agencies to evaluate exceptions that apply to all endangered could potentially harm the their actions with respect to any species wildlife. These prohibitions, in part, southwestern willow flycatcher and that is proposed or listed as endangered make it illegal for any person subject to result in ‘‘take,’’ include, but are not or threatened and with respect to its the jurisdiction of the United States to limited to: critical habitat, if any is being take (includes harass, harm, pursue, (1) Unauthorized handling or designated. Regulations implementing hunt, shoot, wound, kill, trap, or collect; collecting of the species; this interagency cooperation provision or to attempt any of these), import or (2) Destruction/alteration of the of the Act are codified at 50 CFR Part export, ship in interstate commerce in species’ habitat by discharge of fill 402. Section 7(a)(4) requires Federal the course of commercial activity, or sell material, draining, ditching, tiling, pond agencies to confer informally with the or offer for sale in interstate or foreign construction, stream channelization or Service on any action that is likely to commerce any listed species. It also is diversion, or diversion or alteration of jeopardize the continued existence of a illegal to possess, sell, deliver, carry, surface or ground water flow into or out proposed species or result in transport, or ship any such wildlife that of the wetland (i.e., due to roads, destruction or adverse modification of has been taken illegally. Certain impoundments, discharge pipes, proposed critical habitat. If a species is exceptions apply to agents of the stormwater detention basins, etc.); listed subsequently, Section 7(a)(2) Service and State conservation agencies. (3) Livestock grazing that results in requires Federal agencies to ensure that Permits may be issued to carry out direct or indirect destruction of riparian activities they authorize, fund, or carry otherwise prohibited activities habitat; out are not likely to jeopardize the involving endangered wildlife species (4) Activities such as continued continued existence of such a species or under certain circumstances. presence of cattle and fragmentation of destroy or adversely modify its critical Regulations governing permits are at 50 flycatcher habitat that facilitate brood habitat. If a Federal action may affect a CFR 17.22 and 17.23. Such permits are parasitism by the brown-headed listed species or its critical habitat, the available for scientific purposes, to cowbird; and responsible Federal agency must enter enhance the propagation or survival of (5) Pesticide applications in violation into consultation with the Service. the species, and/or for incidental take in of label restrictions. connection with otherwise lawful Questions as to whether specific No conservation plans or habitat activities. activities will constitute a violation of restoration projects specific to the It is the policy of the Service (59 FR section 9 should be directed to Sam F. southwestern willow flycatcher exist on 34272) to identify to the maximum Spiller or Robert M. Marshall at the lands managed by the U.S. Forest extent practicable at the time a species Service’s Ecological Services State Service (USFS), BLM, U.S. Bureau of is listed those activities that would or Office, 2321 West Royal Palm Road, Reclamation (Reclamation), Indian would not constitute a violation of Suite 103, Phoenix, Arizona 85021 Nations, State agencies, or the Service. section 9 of the Act. The intent of this (Telephone 602/640–2720) The USFS and BLM have focussed some policy is to increase public awareness of attention on modifying livestock grazing the effect of a listing on proposed and National Environmental Policy Act practices in recent years, particularly as ongoing activities within a species’ The Fish and Wildlife Service has they affect riparian ecosystems. As range. The Service believes that, based determined that an Environmental mitigation for other projects impacting on the best available information, the Assessment and Environmental Impact riparian habitats, Reclamation is following are examples of actions that Statements, as defined under the engaged in riparian habitat restoration will not result in a violation of section authority of the National Environmental projects in several areas in the range of 9: Policy Act of 1969, need not be E. t. extimus, including some historical (1) Dispersed recreational activities prepared in connection with regulations nesting locations. The BLM currently near willow flycatcher breeding areas adopted pursuant to Section 4(a) of the manages approximately 40 miles of the that do not disrupt normal flycatcher Act. A notice outlining the Service’s upper San Pedro River in Arizona breeding activities and behavior, attract reasons for this determination was (including historic nest sites), as a avian and mammalian predators, nor published in the Federal Register on Riparian National Conservation Area. result in the trampling or destruction of October 25, 1983 (48 FR 49244). Riparian habitat rehabilitation is also riparian breeding habitat; underway at several National Wildlife (2) Federally-approved projects that References Cited Refuges in the breeding range of E. t. involve activities such as discharge of A complete list of all references cited extimus, which are managed by the fill material, draining, ditching, tiling, herein, as well as others, is available Service. The Nature Conservancy pond construction, stream upon request from the Supervisor, manages one of the largest remaining channelization or diversion, or Ecological Services State Office in flycatcher populations, as well as diversion or alteration of surface or Arizona (see ADDRESSES above). several other areas with high recovery ground water flow into or out of the potential. The U.S. Marines have wetland (i.e., due to roads, Author maintained a cowbird control program impoundments, discharge pipes, The primary author of this rule is near the Santa Margarita River to benefit stormwater detention basins, etc.)— Robert M. Marshall, Ecological Services the least Bell’s vireo. This program has when such activity is conducted in State Office in Arizona (see ADDRESSES benefitted nesting southwestern willow accordance with any reasonable and above). flycatchers there. Grand Canyon prudent measures given by the Service National Park has instituted a seasonal in accordance with section 7 of the Act; List of Subjects in 50 CFR Part 17 recreation closure at the remaining site and Endangered and threatened species, with nesting willow flycatchers in the (3) Livestock grazing that does not Exports, Imports, Reporting and record Grand Canyon, and has begun a cowbird attract the brood parasitic brown-headed keeping requirements, and monitoring program. cowbird or result in the destruction of Transportation. Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / Rules and Regulations 10715

Regulation Promulgation PART 17Ð[AMENDED] order under Birds, to the List of Endangered and Threatened Wildlife to 1. The authority citation for Part 17 Accordingly, part 17, subchapter B of read as follows: chapter I, title 50 of the Code of Federal continues to read as follows: Regulations, is amended as set forth Authority: 16 U.S.C. 1361–1407; 16 U.S.C. § 17.11 Endangered and threatened below: 1531–1544; 16 U.S.C. 4201–4245; Pub. L. 99– wildlife. 625, 100 Stat. 3500; unless otherwise noted. * * * * * 2. Section 17.11(h) is amended by (h) * * * adding the following, in alphabetical

Species Vertebrate popu- Historic range lation where endan- Status When listed Critical Special Common name Scientific name gered or threatened habitat rules

******* BIRDS

******* Flycatcher, south- Empidonax traillii, U.S.A. (AZ, CA, CO, Entire ...... E 577 NA NA western willow. extimus. NM, NV, TX, UT).

*******

Dated: February 16, 1995. Mollie H. Beattie, Director, Fish and Wildlife Service. [FR Doc. 95–4531 Filed 2–24–95; 8:45 am] BILLING CODE 4310±55±P