A. Status of the Spectacled Eider - U.S. Fish and Wildlife Service

More documents

Recommendations

Info

A. Status of the Spectacled Eider Reasons for Listing The Service responded to a December 1990 petition to list the Spectacled Eider as endangered by conducting a review of the species’ status. After evaluation of available scientific and commercial information and public comments, the species was designated as threatened on May 10, 1993 (Federal Register 58(88):27474-27480). The primary reasons for listing Spectacled Eiders were their rapid and continuing decline on the Yukon-Kuskokwim Delta (YKD) breeding grounds (a major nesting area) (Dau and Stehn 1991; Stehn et al. 1993) and indications that they may have declined on Alaska’s North Slope (NS) as well. Status and Trends Spectacled Eiders are known to breed in three primary locations: the YKD, the NS, and Arctic Russia (AR) (Figure 1). Limited nesting may also occur on St. Lawrence Island and the Seward Peninsula in Alaska (Pay and Cade 1959). The Spectacled Eider was listed as threatened primarily on the basis of Service estimates that the number of nesting pairs on the YKD had declined from approximately 47,740 pairs in the early 1970s to 1,721 by 1992—a rapid and continuing decline ofover 96% overall (Stehn et al. 1993) (Figure 2). Numbers of nesting Spectacled Eiders on the Kashunuk River (YKD) declined by more than 75% from 1969-1992 (Ely et al. 1994). Corroborating evidence for the decline came from aerial and ground surveys conducted since 1985 that indicated that the YKD breeding population was continuing to decline by 9-14%/year through 1992 (ibid; Figure 3). From 1992-1995, these surveys suggested that the YKD breeding population may have at least temporarily stabilized. In the early 1970s, biologists estimated that approximately 60% of the species’ population nested on the YKD (Dau and Kistchinski 1977); historical population estimates for the NS and AR were highly tentative, however, so this estimate was likely inaccurate. Information from researchers in the Prudhoe Bay oilfields (Warnock and Troy 1992) and Native elders at Wainwright (R. Suydam, pers. comm.) suggest local population declines on the NS. Although no data are available for examining overall trends on the NS or in AR, surveys were recently completed in both areas. Aerial surveys of the NS provided population estimates (uncorrected for visibility) of >9000, 7000, and 7500 for 1993-1995, respectively (W. Lamed, pers. comm.). The breeding distribution of the AR population is extensive and efforts over three breeding seasons were required to complete a comprehensive survey. The minimum estimate (uncorrected for visibility) exceeded 140,000 birds (Hodges and Eldridge 1995). 2
SPECTACLED EIDER Breeding Distribution —— Distinct Breeding Populations Current Breeding Range Historical Breeding Range Figure 1. Breeding distribution of Specta~led Biders. Historical breeding range (cross-batching) is based on anecdotal information from various sources. Current breeding range (heavy outlines) indicates areas where recent surveys hav, confirmed current breeding pair occurrence. Low.densitybreeding may still occur outside these areas. — AU historical range except St. Lawrence Island has been surveyed at least once since 1992. Breeding range appears to be less extensive than it was historically in all three populations~ Dashed lines encircle the three distinct breeding populations. For purposes of this recovery plan, any nesting birds on St. Lawrence Island and the Seward Peninsula will be classified with the North Slope population. (Figureby P. Gallagher). 3
Page 2 and 3: SPECTACLED EIDER RECOVERY PLAN Team
Page 4 and 5: LITERATURE CITATION U.S. Fish and W
Page 6 and 7: EXECUTIVE SUMMARY OF THE RECOVERY P
Page 8 and 9: TABLE OF CONTENTS DISCLAIMER PAGE 1
Page 10 and 11: LIST OF FIGURES Figure 1. Breeding
Page 14 and 15: ) a) j~ 25000 0 2 220000 C ~15000 ~
Page 16 and 17: B. Causes for Decline and Obstacles
Page 18 and 19: Increasing interest in avicultural
Page 20 and 21: Other conservation measures include
Page 22 and 23: D. Natural History of the Spectacle
Page 24 and 25: Figure 4. Yukon-Kuskokwim Delta loc
Page 26 and 27: DEL?A RUSSIA SPECTACLED EIDER RANGE
Page 28 and 29: helicopter surveys in the Prudhoe B
Page 30 and 31: geographic populations, because imm
Page 32 and 33: Figure 8. Study sites and land stat
Page 34 and 35: their diseases (e.g., Schiller 1954
Page 36 and 37: E. Distinct Population Segments The
Page 38 and 39: A final consideration involves info
Page 40 and 41: Trend data are analyzed to inform w
Page 42 and 43: Figure 10. A hypothetical posterior
Page 44 and 45: thresholds are not “magic numbers
Page 46 and 47: Criteria for Reclassifying from Thr
Page 48 and 49: Criteria for Delisting from Threate
Page 50 and 51: The final aspect ofSpectacled Eider
Page 52 and 53: concordance in their descriptions o
Page 54 and 55: data on both levels and effects oft
Page 56 and 57: implicated. In the absence of histo
Page 58 and 59: . - currently small size of the YKD
Page 60 and 61: implementation of the Memoranda ofA
Page 62 and 63:
. take of Spectacled Eiders. In add
Page 64 and 65:
. AlS. Produce a handbook summarizi
Page 66 and 67:
. Bl.4. 1.3. Develop visibility cor
Page 68 and 69:
B2. 1.1. Implement YKD satellite tr
Page 70 and 71:
. Appendix Ill). Since epidermal ag
Page 72 and 73:
. feasible if post-fledging staging
Page 74 and 75:
presumed that their activities have
Page 76 and 77:
contaminants within Spectacled Eide
Page 78 and 79:
limited ability to withstand additi
Page 80 and 81:
surface after a year and is no long
Page 82 and 83:
. The reproductive stages (eggs, yo
Page 84 and 85:
is inadequate to sustain “normal
Page 86 and 87:
___________ 1967. The geese of the
Page 88 and 89:
Dementev, G.P., and N.A. Gladkov (e
Page 90 and 91:
___________ 1 964a. Observations on
Page 92 and 93:
Nelson, E.W: 1887. Report upon natu
Page 94 and 95:
________ P.R. Wade, R.A. Stehn, and
Page 96 and 97:
Robert M. Platte, Migratory Bird Ma
Page 98 and 99:
KEY Task Duration and Costs TBD - T
Page 100 and 101:
TASK 324.2 I 12.4.1 .2 PRIOR- — 2
Page 102 and 103:
TASK I — [37 E12 EI.3 fTYU —PRI
Page 104 and 105:
TASK PRIOR- Dj ITYU — — A12.3 2
Page 106 and 107:
— TASK U — 135.2 PRIOR- TASK DE
Page 108 and 109:
TASK U PRIOR- ITY U TASK DESCRIPTIO
Page 110 and 111:
TASK PRIOR. U — DS.3 3 TASK DESCR
Page 112 and 113:
The final risk factor is the effect
Page 114 and 115:
This PVA will treat two population
Page 116 and 117:
Both aerial surveys are conducted a
Page 118 and 119:
0.2 0.15 -j i 4 0.1 0 -I 0.05 0.08
Page 120 and 121:
emaining before the population reac
Page 122 and 123:
) critical population size; and (2)
Page 124 and 125:
40%. The population growth rate cri
Page 126 and 127:
Table 1-2. Results of simulation wh
Page 128 and 129:
Hilborn, R. and C.J. Walters. 1992.
Page 130 and 131:
APPENDIX II TECHNICAL DETAILS OF TH
Page 132 and 133:
The likelihood function for the par
Page 134 and 135:
initial sample. Then the O~ were re
Page 136 and 137:
LU ~0.8 z -J ~0.6 I-ET1 w107 480 m1
Page 138 and 139:
LITERATURE CITED APPENDIX LI De la
Page 140 and 141:
where x = age. The fertility rate i
Page 142 and 143:
of older females: (1) older females
Page 144 and 145:
RESULTS Solutions for single cause
Page 146 and 147:
0.1 0.08 ~0.06 4 0 0.04 0. 0.02 0 0
Page 148 and 149:
growth rate. Perhaps this can be mo
Page 150 and 151:
decline, by far the fastest way to
Page 152 and 153:
LITERATURE CITED APPENDIX In Bailli
Page 154 and 155:
APPENDIX IV SPECTACLED EIDER RECOVE
Page 156 and 157:
APPENDIX V COMMENTS RECEIVED ON DRA
show all

A. Status of the Spectacled Eider - U.S. Fish and Wildlife Service

Create successful ePaper yourself

Delete template?

Save as template?