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<br />W AIS Document Retrieval
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<br />002G92
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<br />In a review of historical and contemporary records of Empidonax
<br />traillii extimus throughout its range, Unitt (1987) noted that the
<br />species has "declined precipitously * * *" and that "the population
<br />is clearly much smaller now than 50 years ago.' I He believed the total
<br />was "well under' I 1000 pairs, more likely 500 (Unitt 1987). Nesting
<br />groups monitored since that time.have continued to decline (Whitfield
<br />1990, Brown 1991, Sogge and Tibbitts 1992, Whitfield and Laymon,
<br />unpubl. data). Since 1992, more than 800 historic and new locations
<br />have been surveyed range wide to document the status of the
<br />southwestern willow flycatcher (USFWS, unpubl. data). The current known
<br />population of southwestern willow flycatchers is estimated at between
<br />300 and 500 pairs (Sogge et al. 1997). This indicates a critical
<br />population status, with more than 75 percent of the locations where-
<br />flycatchers are found having five or fewer territorial birds and up to
<br />20 percent of the locations having single, unmated individuals. The
<br />distribution of breeding groups is highly fragmented, with groups often
<br />separated by considerable distances (e.g., approximately 88 kilometers
<br />(km) (55 miles) straight-line distance between breeding flycatchers at
<br />Roosevelt Lake, Gila County, Arizona, and the next closest breeding
<br />groups known on either the San Pedro River (Pinal County) or Verde
<br />River (Yavapai County). Additional survey effort, particularly in
<br />southern California, may discover additional small breeding groups.
<br />However, rangewide survey efforts have yielded positive results in
<br />fewer than 10 percent of surveyed locations. Moreover, survey results
<br />reveal a consistent pattern range wide; the southwestern willow
<br />flycatcher population as a whole is comprised of extremely small,
<br />widely-separated breeding groups or unmated flycatchers.
<br />For a thorough discussion of the ecology and life history of the
<br />southwestern willow flycatcher, see Sogge et al. (1997), the proposed
<br />rule to list the southwestern willow flycatcher as endangered with
<br />critical habitat (58 FR 39495) or the final rule listing the
<br />southwestern willow flycatcher as endangered (60 FR 10694) .
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<br />Previous Federal Actions
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<br />On January 25, 1992, a coalition of conservation organizations
<br />petitioned the Service, requesting listing of Empidonax traillii
<br />extimus as an endangered species, under the Act. The petitioners also
<br />appealed for emergency listing, and designation of critical habitat. On
<br />September 1, 1992, the Service published a finding that the petition
<br />presented substantial information indicating that listing may be
<br />warranted and requested public comments and biological data on the
<br />species (57 FR 39664). On July 23, 1993, the Service published a
<br />proposal to list E. t. extimus as endangered with critical habitat (58
<br />FR 39495), and again requested public comments and biological data on
<br />the species. The Service published a final rule to list E. t. extimus
<br />as endangered on February 27/ 1995 (60 FR 10694). The Service deferred
<br />the designation of critical habitat for this endangered species until
<br />July 23, 1995, pursuant to 16 U.S.C. Sec. 1533(b) (6) (C), citing issues
<br />raised in public comments, new information, and the lack of the
<br />economic information necessary to perform the required economic
<br />analysis. The Service reopened the comment period on the proposal to
<br />designate critical habitat. During and following the listing moratorium
<br />and a series of rescissions of listing funds imposed by Congress from
<br />April 1995 to April 1996, the Service took no action on the proposal to
<br />designate critical habitat due to resource constraints. On March 20,
<br />1997, the U.S. District Court of Arizona, in response to a suit by the
<br />Southwest Center for Biological Diversity, ordered the Service to
<br />designate critical habitat for the southwestern willow flycatcher
<br />within 120 days. On July 3, 1997, the Court clarified that order,
<br />noting that the 120-day timeframe was provided for the Service to make
<br />a decision as to whether or not to designate critical habitat and not
<br />to make a substantive determination of designation.
<br />The Service has not previously designated critical habitat for the
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<br />Tuesday, July 22, 1997
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