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

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Increasing interest in avicultural egg collecting was reflected in the increasing numbers of permit applications in the five years before avicultural collecting of Spectacled Eider eggs was banned in 1991 (J. Sheridan, pers. comm.). The reported take of eider eggs for avicultural purposes in those five years--all from the North Slope--did not exceed 150 eggs/year; however, the actual take may have been twice this number (ibid). Many residents of rural communities within the breeding range of Spectacled Eiders suspect that the activities of researchers negatively affect breeding waterfowl. Although the impact of research is probably minimal at the population level, investigations can be disruptive, and a few cases of researcher-induced mortality have occurred. Despite the development of protocols to minimize impacts, the cumulative effects ofresearch activity on Spectacled Eiders have not been adequately documented. Investigations ofeider ecology in Alaska NS oilfields are ongoing (Warnock and Troy 1992; Ritchie and Stickney 1991; Anderson et al. 1991, 1992a, 1992b; Burgess and Stickney 1992; Murphy and Anderson 1992b; TERA 1993, 1995; Smith et al. 1994; Anderson and Cooper 1994; Anderson et al. 1995; Johnson 1995; Anderson and Johnson in press). In the oilfields, the distribution of Spectacled Eiders during the nesting season was altered in response to noise from a compressor plant (Anderson et al. 1992b). In preliminary sampling at Prudhoe Bay, Warnock and Troy (1992) found that Spectacled Eiders and their nests were neither closer to nor farther from oilfield facilities than expected from random sampling, with the exception that water impoundments adjacent to facilities supported above-average densities ofbirds. Mining and petroleum-related activity also occur in Spectacled Eider breeding habitat in AR (Tichotsky 1991), but the extent of these developments and their overall impacts are unknown. Factors Affecting Survival At Sea Threats at sea, both known and potential, represent the greatest source of uncertainty in understanding the Spectacled Eider’s decline. This uncertainty reflects the lack of information about at-sea distribution and ecology. For example, competition for food with other species of seaducks, marine mammals, and possibly fishes could decrease the carrying capacity of winter habitats for Spectacled Eiders. Pacific Walrus (Odobenus rosmarus) and Gray Whale (Eschrichtius robustus) populations may have tripled in size from 1960 to 1980 (Fay et al. 1989), and may have adversely affected food resources used by Spectacled Eiders. Fay et al. (1989) hypothesized that fluctuations occurring in marine bird populations in the Bering Sea may be the result of a complex of changes in fish and invertebrate populations. Eiders may be accumulating environmental contaminants from sources within the marine environment that cause mortality, reduce propensity for nesting, reduce productivity, or reduce juvenile survival. For example, preliminary analysis of tissues from a small sample of birds suggests that some Spectacled Eiders may carry elevated levels of cadmium, selenium, and strontium (K. Trust, pers. comm.). However, baseline levels of these elements have never 8
een determined for ecologically or physiologically similar species. At present, data are lacking to quantify the magnitude and impacts of contaminants on Spectacled Eiders and their habitats. There are also few data on human harvest levels away from the breeding grounds. Spectacled Eiders are taken by subsistence hunters during migration along the coast of northwestern Alaska (Johnson 1971; Braund et al. 1989a, 1989b) as well as in Bering Strait and near St. Lawrence Island (J. Cochrane, pers. comm.). Sport hunters also harvested Spectacled Eiders before 1991, primarily near St. Lawrence Island. On the only sport hunt during which quantitative data were gathered (fall 1990), 137 Spectacled Eiders were taken by two hunters [or“one hunting party”] (C. Dau, pers. comm.). Neither the number of hunters participating in this type of hunt nor the numbers of years during which this sport harvest occurred is known. Diseases and parasites may act synergistically with other stress factors to increase mortality rates at sea, where eiders may experience prolonged environmental stress during winter and spring storms. Little is known about diseases and parasites in Spectacled Eider populations. Dau (1974) believed juvenile birds suffered substantial mortality during their post-fledging transition to salt-water habitats, due in part to stress from parasite loads. Commercial fishing may impact Spectacled Eiders by disturbing benthic feeding areas. In addition, accidental strikes affecting “hundreds” of unidentified eiders have been reported from the winter crab fishery in the northern Bering Sea (S. Tuttle, pers. comm.). Trawlers operating in Russian waters may be accidentally catching eiders in fishing nets or removing foods important to Spectacled Eiders. In summary, many potential threats to Spectacled Eiders in the marine environment have been suggested, but due to a lack of research, few have been confirmed. C. Current Management U.S. Fish and Wildlife Service The Service has implemented numerous conservation measures for Spectacled Eiders. These include protecting birds nesting near activities that are federally funded, authorized, or conducted (through Section 7 consultations) and overseeing Spectacled Eider research and management activities (through intra-Service Section 7 consultations and Section 10 endangered species permitting). For example, standard provisions to locate and avoid impacts to nesting and brood-rearing birds have been implemented successfully in the NS oilfields (Appendix IV). 9
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 12 and 13: A. Status of the Spectacled Eider R
Page 14 and 15: ) a) j~ 25000 0 2 220000 C ~15000 ~
Page 16 and 17: B. Causes for Decline and Obstacles
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
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. Appendix Ill). Since epidermal ag
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. feasible if post-fledging staging
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presumed that their activities have
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contaminants within Spectacled Eide
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limited ability to withstand additi
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surface after a year and is no long
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. The reproductive stages (eggs, yo
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is inadequate to sustain “normal
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___________ 1967. The geese of the
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Dementev, G.P., and N.A. Gladkov (e
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___________ 1 964a. Observations on
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Nelson, E.W: 1887. Report upon natu
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________ P.R. Wade, R.A. Stehn, and
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Robert M. Platte, Migratory Bird Ma
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KEY Task Duration and Costs TBD - T
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TASK 324.2 I 12.4.1 .2 PRIOR- — 2
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TASK I — [37 E12 EI.3 fTYU —PRI
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TASK PRIOR- Dj ITYU — — A12.3 2
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— TASK U — 135.2 PRIOR- TASK DE
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TASK U PRIOR- ITY U TASK DESCRIPTIO
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TASK PRIOR. U — DS.3 3 TASK DESCR
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The final risk factor is the effect
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This PVA will treat two population
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Both aerial surveys are conducted a
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0.2 0.15 -j i 4 0.1 0 -I 0.05 0.08
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emaining before the population reac
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) critical population size; and (2)
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40%. The population growth rate cri
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Table 1-2. Results of simulation wh
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Hilborn, R. and C.J. Walters. 1992.
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APPENDIX II TECHNICAL DETAILS OF TH
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The likelihood function for the par
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initial sample. Then the O~ were re
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LU ~0.8 z -J ~0.6 I-ET1 w107 480 m1
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LITERATURE CITED APPENDIX LI De la
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where x = age. The fertility rate i
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of older females: (1) older females
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RESULTS Solutions for single cause
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0.1 0.08 ~0.06 4 0 0.04 0. 0.02 0 0
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growth rate. Perhaps this can be mo
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decline, by far the fastest way to
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LITERATURE CITED APPENDIX In Bailli
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APPENDIX IV SPECTACLED EIDER RECOVE
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APPENDIX V COMMENTS RECEIVED ON DRA
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