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

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presumed that their activities have minimal effects on bird populations. Yet data are lacking to demonstrate that biological studies do not affect Spectacled Eider nesting propensity, clutch size, nesting success, or bird survival. The effects of ground studies, aerial surveys, and cumulative research-related activities on Spectacled Eiders should be investigated and quantified. Quantifying the potential effects will also resolve issues of potential bias in sampling design, guide mitigation measures to minimize investigator effects and permit an assessment of whether further, intensive studies are appropriate. This information is also important for addressing the hypothesis that human disturbance contributed to the Spectacled Eider decline or is an obstacle to recovery (task CS.7). C3. 1. Evaluate the effects of nasal markers. On-going marking studies include both nasal markers and leg bands. Since birds are merely observed and not re-captured for marker identification, nasal markers provide substantially more reliable re-sighting rates than do less visible leg bands. Although nasal markers are widely used on waterfowl and are presumed to have minimal adverse effects, data are lacking to demonstrate that marker attachment does not affect survival, nesting propensity, clutch size, and nesting success. A study sbould be conducted on the effects of nasal markers on birds that winter in subarctic, marine environments, preferably using a similar species rather than Spectacled Eiders. Quantifying the potential effects will resolve issues ofbias in the sample design and permit an assessment of whether marking studies are appropriate. C3.2. Evaluate the impacts of nesting studies. The study should determine an accurate, unbiased estimate of change in predation or abandonment rates as a result of biologists visiting nests and gathering information on eggs and hens during incubation. (Three year study initiated on YKD in 1994). C3.3. Convene a workshop to develop methods for evaluating other research-related cff~is. 1. Presently, methods have not been developed that would provide an accurate and unbiased estimate of the effects of aerial survey over-flights. In addition, the overall impact of research activities needs to be investigated, including but not limited to camp establishment and occupation, aircraft support, and, particularly, travel around a study area not directed to specific nests. Methods for determining specific research effects, such as increased predation or nest abandonment, need to be determined. Workshop participants should include biologists with expertise in studying disturbance effects, statisticians, and Native representatives who are concerned about this issue. Implementation ofadditional impacts studies should be based on the results of this workshop. C4. Refine the demographic model for Spectacled Eiders. Understanding the population dynamics of this species will result in a more realistic assessment of various, potential causes of decline and obstacles to recovery. An improved model could improve our ability to determine the costs and benefits of reducing certain obstacles to recovery. The model in Appendix HI should be refined based on data obtained from tasks under tasks Cl and C2. A sensitivity analysis should be conducted to assess the effects of uncertainty and environmental 64
stochasticity on parameter estimation. The accuracy of parameter values required for various levels of confidence in the model must be determined, in addition to identifying how big an error in the estimates causes significant changes in the population parameters. Errors in current estimates may need to be reduced to improve the predictive capacity of the population model. The model should incorporate recruitment and survival rates of similar species until Spectacled Eider data become available. If the AR population is not declining, data on reproduction and survival from the AR population would be particularly valuable to further the understanding of - “normal” Spectacled Eider dynamics.- - The effects of changes in reproductive -and survival - parameters on Spectacled Eider populations and recovery should be investigated through simulations. This would include determining the magnitude of change in each parameter necessary to have a significant impact on recovery as well as determining likely causes for the decline. Parameters should include: adult survival, age offirst reproduction, nesting propensity, clutch size, hatching success, brood survival, duckling survival, and fledgling survival. CS. Summarize and evaluate available information on potential causes of decline and obstacles to recovery. Understanding the relative, cumulative, or synergistic impacts of various influences on eider populations will assist in establishing priorities for recovery efforts. -Preliminary investigations outlined in this plan will help to determine the potential magnitude of the effects on eider populations of contaminants, competition, subsistence harvest, predation, fisheries, NS oil development activities, disturbance, and changes in long-term weather patterns. Data pertaining to these potential cause(s) of the eiders’ decline and obstacles to recovery have yet to be comprehensively summarized and evaluated. Each of these topics should be investigated and the hypotheses refined so that data collection during the exploratory research phase is focused on hypothesis-testing. The following 8 tasks call for preparing summary documents addressing 2 hypotheses about potentially major influences on Spectacled Eider populations: (1) this factor was an important cause of the Spectacled Eider population decline; and (2) this factor is an important obstacle to population recovery. These documents should summarize and evaluate all existing information, including evaluation through modeling, where appropriate. These summaries will be critical in developing work plans and formulating more precise, testable hypotheses as research continues. Because our present understanding of Spectacled Eider population dynamics is so limited, these topics should be addressed individually at first. In time, the goal should be to develop complex population models that permit assessment of multiple factors simultaneously. Tasks CS.1-CS. 10 should be repeated regularly as data accumulate on each topic. CS. 1. Prepare summary report about environmental contaminants. The potential relationships between contamination and the observed historical declines and recovery should be evaluated and summarized in a report. Existing information on environmental 65
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SPECTACLED EIDER RECOVERY PLAN Team
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LITERATURE CITATION U.S. Fish and W
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EXECUTIVE SUMMARY OF THE RECOVERY P
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TABLE OF CONTENTS DISCLAIMER PAGE 1
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LIST OF FIGURES Figure 1. Breeding
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A. Status of the Spectacled Eider R
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) a) j~ 25000 0 2 220000 C ~15000 ~
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B. Causes for Decline and Obstacles
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Increasing interest in avicultural
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Other conservation measures include
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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 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)
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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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A. Status of the Spectacled Eider - U.S. Fish and Wildlife Service

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