Golden-Cheeked Warbler Recovery Plan
Total Page:16
File Type:pdf, Size:1020Kb
GOLDEN-CHEEKED WARBLER RECOVERY PLAN U.S. FISH AND WILDLIFE SERVICE REGION 2, ALBUQUERQUE, NEW MEXICO 1992 cGEIST-c1-IEEICED WA~H~JL~ER HEcGXTE I~ PT~N Prepared by Dean P. Keddy-Hector Texas Natural Heritage Program Texas Parks and Wildlife Department 3000 South IH—35, Suite 100 Austin, TX 78704 for United States Fish and Wildlife Service Austin, Texas Edited by Carol J. Beardmore U.S. Fish and Wildlife Service 611 East Sixth Street, Suite 407 Austin, Texas 78701 Approved: ~ ~ Regi al irector, U.S. Fish and Wildlife Service Date: SEP~ 1932 Disclaimer Recovery plans delineate reasonable actions that are believed to be required to recover and/or protect listed species. Plans are published by the U. S. Fish and Wildlife Service, sometimes prepared with the assistance of recovery teams, contractors, State agencies, and others. Objectives will be attained and any necessary funds made available subject to budgetary and other constraints affecting the parties involved, as well as the need to address other priorities. Estimates of cost and task duration as listed in Part III have some uncertainty depending on the nature of the task. Duration of some research tasks are unknown because they are experimental in nature and it is difficult to predict the interval required to complete the task or to attain required data sets for statistical analysis. Costs of some tasks are uncertain when they involve activities for which there exists no previous cost experience and/or when they are dependent on earlier tasks. Recovery plans do not necessarily represent the views nor the official positions or approval of any individuals or agencies involved in the plan formulation, other than the U.S. Fish and Wildlife Service. They represent the official position of the U.S. Fish and Wildlife Service only after they have been signed by the Regional Director or Director as approved. Approved recovery plans are subject to modification as dictated by new findings, changes in species • status, and the completion of recovery tasks. i Literature Citations Literature citations of this document should read as follows: U.S. Fish and Wildlife Service. 1992. Golden-cheeked Warbler (Dendroica chrysoparia) Recovery Plan. Albuquerque, New Mexico. 88 pp. Additional copies may be purchased from: Fish and Wildlife Reference Service 5430 Grosvenor Lane, Suite 110 Bethesda, ‘Maryland 20814 (301) 492—6403 or 1—800—582—3421 The fee for the Plan varies depending on the number of pages of the Plan. ii Acknowledclments The author would like to acknowledge individuals who reviewed earlier drafts of this document: Bill Armstrong, Jon Barlow, David Diamond, Fred Gehlbach, and Jane Lyons. In addition, a number of people assisted by providing information through many useful discussions. Individuals contributing in this manner include Carol Beardmore, Terry Cook, John Cornelius, Tim Hayden, Clif Ladd, Dave Lyter, Warren Pulich, Sr., Warren Pulich, Jr., Susan Rust, Tim Schumann, Chuck Sexton, David Steed, and Paul Turner. Alisa Shull and Jim Lewis provided significant comment on the draft plan. The illustration on the cover was drawn by and provided compliments of Hal Irby. iii Executive Summary Current Species Status: The golden—cheeked warbler is listed as endangered. Habitat destruction in the breeding range has accelerated (Wahl et al. 1990), since the initial surveys of Pulich (1976). Clearing of pine-oak woodlands in Mexico and Central America is eliminating habitat on the winter range and migration corridor. Habitat Requirements and Limitincr Factors: During the breeding season, golden—cheeked warbiers inhabit woodlands containing Ashe juniper (Juniperus ashei) in combination with various deciduous trees such as Texas oak (Quercus bucklevi), scaley bark oak (~. sinuata var. breviloba), and Plateau live oak (~. fusiformis) The essential breeding season requirement is the presence of suitable nesting material in the form of bark strips from Ashe junipers. Other limiting factors may include availability of arthropod prey, a moderate to high degree of canopy cover, nest parasitism and predation, and proximity to water. Recovery Objective: Delisting. Recovery Criteria: The golden—cheeked warbler will be considered for delisting when (1) sufficient breeding habitat has been protected to ensure the continued existence of at least one viable, self-sustaining population in each of eight regions outlined in the plan, (2) the potential for gene flow exists across regions between demographically self—sustaining populations where needed for long-term viability; (3) sufficient and sustainable non-breeding habitat exists to support the breeding populations, (4) all existing golden-cheeked warbler populations on public lands are protected and managed to ensure their continued existence, and (5) all of these criteria have been met for 10 consecutive years. Actions Needed 1. Studies of golden-cheeked warbler population status and biology, ecology, habitat requirements, and threats on the breeding ground and in the winter range and along their migration corridor. 2. Protection of existing populations and habitat in the breeding range, wintering range, and along the migration corridor. 3. Increased voluntary protection of warbler habitat. 4. Enhancement and maintenance of the quality of warbler habitat on public and private lands. 5. Increased public awareness of the importance of the species and other endangered species. 6. Regulatory protection. iv .: Total Estimated Cost of Recovery (Dollars x 1000) Priority 1 Priority 2 Priority 3 Total Fiscal Year Tasks Tasks Tasks 1993 2,136 499 243 $ 2,878 1994 2,081 560 137 $ 2,778 1995 1,537 540 152 $ 2,229 1996 1,000 300 75 $ 1,375 1997 500 250 30 $ 780 1998 500 200 30 $ 730 1999 250 200 30 $ 480 2000—2008 100 200 30 $ 330 $11,889 Date of Recovery: If the plan is implemented as outlined, the anticipated year that the delisting criteria should be met is 2008. v : Table of Contents Disclaimer .... i Literature Citations • . ii Acknowledgments iii Executive Summary iv Table of Contents • . vi List of Tables and Figures • . vii I. Introduction and Background 1 A. Legal Status and Recovery Priority .... 1 B. ‘Description 2 C. Taxonomy 3 D. Distribution 4 E. Habitat 7 F. Nesting Ecology 13 G. Diet and Feeding Behavior 16 H. Population Size 17 I. Reasons for Listing and Current Threats 21 J. Conservation Measures 29 K. Existing Public Lands with GCW Habitat 31 L. Recovery Strategy 35 II. Recovery A. Objective and Criteria • . 40 B. Recovery Outline 41 C. Narrative Outline for Recovery Actions 44 D. Literature Cited • . 57 III. Implementation Schedule 66 IV. Appendix - Comments 74 vi List of Tables and Figures Tables Page Table 1. Historical Changes in Amounts of Golden-cheeked warbler breeding habitat • . 19 Table 2. Counties Containing at Least 1,000 ha of Golden-Cheeked Warbler Habitat. • . 22 Table 3. Total Hectares of some State and Federal Lands within the Breeding distribution of the Golden-Cheeked Warbler • . • . 33 Figures Figure 1. Breeding Range of the Golden-Cheeked Warbler (from Pulich 1976) 5 Figure 2. Winter Range and Migration Records of the Golden-Cheeked Warbler (from Perrigo et al. 1990) 6 Figure 3. Distribution of Some Public Lands Within the Breeding Range of the Golden-Cheeked Warbler • . 32 Figure 4. Regions 1-8 for Golden-cheeked Warbler Populations 36 vii I. INTRODUCTION AND BACKGROUND The Golden-cheeked warbler (Dendroica chrysoparia) (GCW or warbler) breeds only in the mixed evergreen-deciduous woodlands of central Texas and winters in the highland pine- oak woodlands of southern Mexico and northern Central America. Human activities have eliminated much warbler habitat within parts of the warbler’s range that existed at the time of Pulich’s (1976) initial surveys in 1962. Recent surveys suggest that the rate of habitat loss is accelerating as suburban developments spread into prime warbler habitat along the Balcones Escarpment, especially in the growth corridor from Austin to San Antonio (Wahl et al. 1990). A. LEGAL STATUS AND RECOVERY PRIORITY The Golden-cheeked warbler was placed on the Endangered Species list on May 4, 1990 by means of an emergency rule (55 FR 18844). At the same time the emergency rule was published, a proposed rule to “permanently” list the species was published (55 FR 18846). The final rule listing the golden-cheeked warbler as endangered under the Endangered Species Act was published on December 27, 1990 (55 FR 53153). This species was added to the Texas Parks and Wildlife Department’s list of endangered species on’February 19, 1991 (Executive Order No. 91-001). The GCW has a recovery priority of 2C. According to the Services s criteria, this indicates a species with a high degree of threats; in conflict with construction or development projects or other forms of economic activity; and, a high potential for recovery. 1 B. DESCRIPTION Adult males in breeding plumage have yellow cheeks outlined in black with a thin black line through each eye and extending backwards from the eye. Upper breast and throat are black. Lower breast and belly are white with some lateral black spotting or streaking. The back is blackish. Wings are blackish with two white wingbars. Tail feathers are black, except that the outermost tail feather on each side is white with a black shaft line. Upper and lower mandibles are black. Legs and feet are black. Eyes are dark brown. The male is the only North American warbler with brilliant yellow cheeks completely outlined in black (Ridgway 1902, Bent 1953, Griscom and Sprunt 1957, Pulich 1965, Oberholser 1974, Pulich 1976) Winter plumage of adult males is similar to the breeding plumage except that the black feathers of the throat are edged with yellow or cream. Adult females are less strikingly marked than adult males. The back is dark olive-green with thin black streaks. The cheeks of females are yellowish but less brilliant than in males. The center of the throat is also yellowish, grading to pale buff or white on the abdomen.