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Geology topics

Margaret R. Petersen

Publications and source records attributed to Margaret R. Petersen.

At least 37 records · Page 2Linked to original sources
USGS2005

Individual variation in staging and timing of spring migration of Pacific common eiders in Alaska

Timing of migration and characterization of migration patterns of birds are usually based on dates of peak migration to and from staging, wintering, and breeding areas used by the bulk of a species. For Pacific common eiders (Somateria mollissima v-nigrum), as well as other species, the timing of migration into and through the Beaufort Sea is based on counts of birds past land or ice-based sites and radar observations, and arrival dates to colonies determined by influxes of birds seen by ground observers. With the continued and proposed development of nearshore and offshore waters of the Beaufort Sea, there is an expanding need to manage local populations. Observations of individual Pacific common eiders can provide a more complete understanding of local populations as well as variability among populations. This study was designed to determine factors influencing migration patterns of individuals nesting in the western Beaufort Sea from their wintering locations along the Chukotka Peninsula, through the eastern Chukchi and western Beaufort seas, until their arrival to their nesting area. The Simpson Lagoon/Maguire Island nesting colonies are 1300-1400 km from the primary winter area. Eiders enter the Beaufort Sea at Point Barrow then move east 300-350 km to their nesting colonies. Nesting adult females were marked with satellite transmitters during summer then followed the next spring and early summer. Transmitters were programmed to provide location data every 3 days (2001, n = 12) or daily (2002 and 2004, n = 7 and 18, respectively) beginning 15 April. I expected the dates of arrival to the colony to vary with weather during migration (Point. Barrow to the colony) and general conditions in spring (early or late year based on differences in temperatures from the long term norm for April, May, and June). All individuals returned to the colony area they were marked the previous year. Data were consistent with other “short” distance migrants. There were no correlations of the dates of arrival to the dates birds left the wintering area, the total days spent staging, wind speed or direction, temperature, weather, or seasonal differences in temperature from the long term average, a plethora of non-significant results. However, two patterns emerged: some birds migrated about 550 km and staged in the eastern Chukchi Sea before migrating to the colonies, while others went directly either to the colony area (1300 km) or elsewhere within the western Beaufort. I will present preliminary analysis and several hypotheses regarding these two strategies.

Alaska↗
USGS2004

Concentrations of metals and trace elements in blood of spectacled and king eiders in northern Alaska, USA

In 1996, we measured concentrations of arsenic, barium, cadmium, lead, mercury, and selenium in blood of adult king (Somateria spectabilis) and spectacled (Somateria fischeri) eiders and duckling spectacled eiders from northern Alaska, USA. Concentrations of selenium exceeded background levels in all adults sampled and 9 of 12 ducklings. Mercury was detected in all adult spectacled eiders and 5 of 12 ducklings. Lead concentrations were above the clinical toxicity threshold in one duckling (0.64 ppm) and two adult female spectacled eiders (0.54 and 4.30 ppm). Concentrations of cadmium and mercury varied between species; barium, cadmium, mercury, and selenium varied between sexes. In female spectacled eiders, mercury concentrations increased during the breeding season and barium and selenium levels decreased through the breeding season. Selenium declined at 2.3 ± 0.9% per day and levels were lower in spectacled eiders arriving to the breeding grounds in northern Alaska than in western Alaska. The variation in selenium levels between breeding areas may be explained by differences in timing and routes of spring migration. Most trace elements for which we tested were not at levels currently considered toxic to marine birds. However, the presence of mercury and elevated lead in ducklings and adult female spectacled eiders suggests these metals are available on the breeding grounds.

Alaska↗
USGS2004

Winter ecology of Spectacled Eiders: Environmental characteristics and population change

We described characteristics of the wintering area used by Spectacled Eiders ( Somateria fischeri ) in the Bering Sea, Alaska, and evaluated these characteristics in relation to long-term population trends. Remoteness, limited daylight, and extreme weather conditions precluded direct observations, so we derived the location of the wintering area from satellite telemetry, ice conditions from remotely sensed data, weather conditions from archived data sets, and benthic communities from the literature. Based on analyses of two indices spanning 1957-2002 and 1988-2002, we identified no single environmental parameter that explained the precipitous decline in nesting populations in western Alaska. In general, we found that the number of days with extreme sea ice in winter, extreme winds, and winds in spring explained the greatest variability in annual indices. These analyses support the conclusion that annual population estimates on the breeding grounds can be negatively impacted by extended periods of dense sea-ice concentration and weather during the previous winter. Examination of population indices did not support the hypothesis that changes in benthic community on the wintering grounds have contributed to the decline or inhibited the recovery of the Spectacled Eider breeding population in western Alaska.

Alaska↗
USGS2004

Lack of spatial genetic structure among nesting and wintering King Eiders

The King Eider (Somateria spectabilis) has been delineated into two broadly distributed breeding populations in North America (the western and eastern Arctic) on the basis of banding data and their use of widely separated Pacific and Atlantic wintering areas. Little is known about the level of gene flow between these two populations. Also unknown is whether behavioral patterns common among migratory waterfowl, such as site fidelity to wintering areas and pair formation at these sites, have existed for sufficient time to create a population structure defined by philopatry to wintering rather than to nesting locations. We used six nuclear microsatellite DNA loci and cytochrome b mitochondrial DNA sequence data to estimate the extent of spatial genetic differentiation among nesting and wintering areas of King Eiders across North America and adjacent regions. Estimates of interpopulation variance in microsatellite allele and mtDNA haplotype frequency were both low and nonsignificant based on samples from three wintering and four nesting areas. Results from nested clade analysis, mismatch distributions, and coalescent-based analyses suggest historical population growth and gene flow that collectively may have homogenized gene frequencies. The presence of several unique mtDNA haplotypes among birds wintering near Greenland suggests that gene flow may now be more limited between the western and eastern Arctic, which is consistent with banding data.

Condor↗
USGS2003

Post-breeding distribution of Long-tailed Ducks Clangula hyemalis from the Yukon-Kuskokwim Delta, Alaska

Breeding populations of Long-tailed Ducks Clangula hyemalis have declined in western Alaska, particularly on the Yukon-Kuskokwim (Y-K) Delta, and the species is currently considered a species of particular concern by the U.S. Fish & Wildlife Service in Alaska. Potential factors that may have contributed to this decline that occurred away from the breeding grounds could not be considered since moulting and wintering areas for this population were unknown. A study was conducted in 1998 and 1999 to locate the moulting and wintering areas of the Y-K Delta breeding population. VHF and satellite transmitters were deployed to identify areas used by moulting birds. Based on the locations identified by satellite telemetry, aerial surveys were flown to locate birds marked with VHF transmitters, then low-level aerial surveys were designed and conducted to determine the number of birds using these and adjacent areas. Moulting locations of 54 marked female Long-tailed Ducks were identified: 13 marked females were found in wetlands and large lakes on the Y-K Delta, 11 in coastal lagoons at St Lawrence Island, Alaska, and two along the coast of the Chukotka Peninsula, Russia. A autumn staging area was identified along the east coast of the Chukotka Peninsula which was used by seven of 10 birds with satellite transmitters providing locations during that period. Birds wintered in coastal waters of the North Pacific Ocean north of 50°N and between 150°E and 130°W. The wide distribution of birds in winter suggests little probability of a single factor in winter contributing to the decline.

Alaska↗
USGS2002

Concentrations of trace elements in eggs and blood of spectacled and common eiders on Yukon-Kuskokwim Delta, Alaska, USA

We examined the relations among nesting success, egg viability, and blood and egg concentrations of As, Cd, Pb, Hg, and Se in a threatened population of spectacled eiders (Somateria fischeri) and a sympatric population of common eiders (S. mollissima) on the Yukona??Kuskokwim Delta, Alaska, USA, during 1995 and 1996. During the early breeding season, males and females had mean Se concentrations in their blood of 19.2 I?g/g and 12.8 I?g/g wet weight, respectively. Blood Se concentrations of females were correlated with egg concentrations. During brood rearing, blood Se levels were higher in adult females than in ducklings. Blood concentrations of Pb in spectacled eider females were higher than in common eider females captured at hatching, but blood concentrations of Se were similar. Trace element concentrations were not related to nest success or egg viability. We submit that nest success and egg viability of spectacled eiders are not related to concentrations of the trace elements we measured. Because blood Se concentrations declined rapidly through the breeding season and were not related to nest success or egg viability, we suggest that spectacled eiders are exposed to high concentrations of Se during winter that pose little threat to this population.

Alaska↗
USGS2002

Population structure of Pacific Common Eiders breeding in Alaska

We used satellite telemetry to study the migration routes and wintering areas of two allopatric breeding populations of Pacific Common Eiders (Somateria mollissima v-nigrum) in Alaska: the Yukon-Kuskokwim Delta, and the western Beaufort Sea coast. Only 6% (2 of 36) of females wintered within the wintering area of the other breeding population. Both breeding populations wintered in the closest available ice-free habitat, perhaps to minimize migratory distance. Two Beaufort Sea females wintered in areas used by Yukon-Kuskokwim Delta females, implying potential gene flow among breeding areas. Yet, we conclude that these two populations are largely geographically isolated throughout the annual cycle and the environmental factors influencing survival and reproduction likely differ between these groups of birds. Thus, regardless of the potential gene flow among breeding populations, we suggest that birds from these two breeding areas should be managed as separate populations. ?? The Cooper Ornithological Society 2002.

Condor↗
USGS2001

Sex-biased gene flow in spectacled eiders (Anatidae): Inferences from molecular markers with contrasting modes of inheritance

Genetic markers that differ in mode of inheritance and rate of evolution (a sex-linked Z-specific microsatellite locus, five biparentally inherited microsatellite loci, and maternally inherited mitochondrial [mtDNA] sequences) were used to evaluate the degree of spatial genetic structuring at macro- and microgeographic scales, among breeding regions and local nesting populations within each region, respectively, for a migratory sea duck species, the spectacled eider ( Somateria fisheri ). Disjunct and declining breeding populations coupled with sex-specific differences in seasonal migratory patterns and life history provide a series of hypotheses regarding rates and directionality of gene flow among breeding populations from the Indigirka River Delta, Russia, and the North Slope and Yukon-Kuskokwim Delta, Alaska. The degree of differentiation in mtDNA haplotype frequency among breeding regions and populations within regions was high (ϕ CT = 0.189, P < 0.01; ϕ SC = 0.059, P < 0.01, respectively). Eleven of 17 mtDNA haplotypes were restricted to a single breeding region. Genetic differences among regions were considerably lower for nuclear DNA loci (sex-linked: ϕ ST = 0.001, P > 0.05; biparentally inherited microsatellites: mean θ = 0.001, P > 0.05) than was observed for mtDNA. Using models explicitly designed for uniparental and biparentally inherited genes, estimates of spatial divergence based on nuclear and mtDNA data together with elements of the species' breeding ecology were used to estimate effective population size and degree of male and female gene flow. Differences in the magnitude and spatial patterns of gene correlations for maternally inherited and nuclear genes revealed that females exhibit greater natal philopatry than do males. Estimates of generational female and male rates of gene flow among breeding regions differed markedly (3.67 × 10 −4 and 1.28 × 10 −2 , respectively). Effective population size for mtDNA was estimated to be at least three times lower than that for biparental genes (30,671 and 101,528, respectively). Large disparities in population sizes among breeding areas greatly reduces the proportion of total genetic variance captured by dispersal, which may accelerate rates of inbreeding (i.e., promote higher coancestries) within populations due to nonrandom pairing of males with females from the same breeding population.

Alaska↗
USGS2000

Infectious bursal disease virus antibodies in eider ducks and Herring Gulls

We measured antibodies to infectious bursal disease virus (IBDV) in blood of nesting Common Eider ( Somateria mollissima ) females and immature Herring Gulls ( Larus argentatus ) in the Baltic Sea, and in blood of Spectacled Eider ( Somateria fischeri ) females nesting in a remote area of western Alaska. Positive (≥ 1:16) IBDV titers occurred in 75% of the eiders and 45% of the Herring Gull chicks. In eiders, the prevalence of positive titers differed among locations. We found no evidence that IBDV exposure impaired the immune function of Herring Gull chicks, based on their response to inoculation of sheep red blood cells. We suggest that eider ducks and Herring Gulls have been exposed to IBDV, even in locations where contact with poultry is unlikely. The presence of this virus in wild bird populations is of concern because it causes mortality of up to 30% in susceptible poultry.

Alaska↗
USGS2000

Annual survival and site fidelity of Stellar's Eiders molting along the Alaska Peninsula

Populations of Steller's eiders ( Polysticta stelleri ) molting and wintering along the Alaska Peninsula have declined since the 1960's. We captured and marked a large sample of Steller's eiders molting in 2 lagoons along the Alaska Peninsula between 1975-97. We used mark-recapture analysis techniques to estimate annual survival and movement probabilities within and among lagoons for male and female eiders. Estimates of annual survival (±SE) were 0.899 ± 0.032 for females and 0.765 ± 0.044 for males. Both sexes showed high rates of fidelity to specific molting locations (>95%) within lagoons; yet we found no evidence that annual probability of survival differed among groups molting in different locations either within or among lagoons. We found weak evidence that annual survival decreased between the periods 1975-81 and 1991-97. The lower survival of males compared to females is unusual for waterfowl and may result in a female-biased sex ratio. We conclude that a decrease in adult survival may have initiated the long-term population decline. Further, a shortage of males may be limiting reproductive potential.

Alaska↗
USGS2000

Distribution of recoveries of Steller's Eiders banded on the lower Alaska Peninsula, Alaska

Molting adult Steller's Eiders ( Polysticta stelleri ) were banded at Izembek Lagoon (1961-1998) and Nelson Lagoon (1995-1997) along the lower Alaska Peninsula to determine breeding distribution and movements. Of 52,985 Steller's Eiders banded, 347 were recovered. The overall low recovery rate may not be indicative of harvest levels but may be due to low reporting rates of bands. Almost all recoveries during summer were from Russia and recovery rates did not differ between sexes. We found no evidence that Steller's Eiders molting in specific locations were more likely to be recovered in specific geographic locations in Russia. Our recoveries suggest that Steller's Eiders molting along the Alaska Peninsula were from Russian breeding sites and from remnant breeding populations in Alaska.

Alaska↗
USGS1999

At-sea distribution of Spectacled Eiders: A 120-year-old mystery resolved

The at-sea distribution of the threatened Spectacled Eider ( Somateria fischeri ) has remained largely undocumented. We identified migration corridors, staging and molting areas, and wintering areas of adult Spectacled Eiders using implanted satellite-transmitters in birds from each of the three extant breeding grounds (North Slope and Yukon-Kuskokwim Delta in Alaska and arctic Russia). Based on transmitter locations, we conducted aerial surveys to provide visual confirmation of eider flocks and to estimate numbers of birds. We identified two principal molting and staging areas off coastal Alaska (Ledyard Bay and eastern Norton Sound) and two off coastal Russia (Mechigmenskiy Bay on the eastern Chukotka Peninsula, and the area between the Indigirka and Kolyma deltas in the Republic of Sakha). We estimated that >10,000 birds molt and stage in monospecific flocks at Mechigmenskiy and Ledyard bays, and several thousand molt and stage in eastern Norton Sound. We further identified eastern Norton Sound as the principal molting and staging area for females nesting on the Yukon-Kuskokwim Delta, and Ledyard Bay and Mechigmenskiy Bay as the principal molting and staging areas for females nesting on the North Slope. Males marked at all three breeding grounds molt and stage in Mechigmenskiy Bay, Ledyard Bay, and the Indigirka-Kolyma delta region. Males from the Yukon-Kuskokwim Delta molt and stage mainly at Mechigmenskiy Bay. Equal numbers of males from the North Slope molt and stage at all three areas, and most males from arctic Russia molt and stage at the Indigirka-Kolyma delta region. Postbreeding migration corridors were offshore in the Bering, Chukchi, and Beaufort seas. In winter, eiders were in the Bering Sea south of St. Lawrence Island. Our estimates from surveys in late winter and early spring suggest that at least 333,000 birds winter in single-species flocks in the pack ice in the Bering Sea.

Alaska↗
USGS1999

Behaviour and ecology of sea ducks

In November 1995... a full-day symposium on the biology of sea ducks was held. The papers in this volume were presented at this symposium. It is hoped that by synthesizing this information, more informed management decisions for sea ducks may emerge. The symposium contents help to emphasize the seriousness of some conservation issues facing sea ducks, notably the possible endangerment of the eastern population of Barrow's Goldeneye and the dwindling number of eider ducks in the Nearctic, while also providing new data on the behaviour and habitat use of this beautiful group of ducks.

Occasional Paper of the Canadian Wildlife Service↗
USGS1998

Blood lead concentrations of spectacled eiders near the Kashunuk River, Yukon Delta National Wildlife Refuge, Alaska

We collected, 342 blood samples from spectacled eiders ( Somateria fischeri ) on their breeding grounds in western Alaska from late May through to early August 1993–1995. Lead concentrations of ≥0.50 p.p.m. wet weight were found in the blood of 20% of the adult female eiders, 2% of the adult males and 6% of the ducklings. Lead was detected (≥0.02 p.p.m.) more frequently in the blood of adult females than in adult males or ducklings and the maximum concentrations were 14.37, 0.50 and 4.28 p.p.m. wet weight, respectively. In adult females, there was a significant difference in the proportion of detectable blood lead concentrations between three collection times (arrival/nesting, hatch and brood rearing), with the highest proportion (92%) occurring at hatch. Nine hens with blood lead concentrations of ≥0.50 p.p.m. were captured a second time several weeks to 1 year later. In the hens sampled twice at intervals of several weeks, the blood lead concentrations increased and declined at mean daily rates of 1.10 and 0.94, respectively. The lead concentrations in the blood of adults were not correlated with body weights. Radiographs were taken of 119 eiders and corresponding blood samples from 98 of these birds were analysed for lead. Ingested shot was seen in X-rays of 12 adults and three ducklings and, of the 13 blood samples tested, all had detectable lead concentrations. Of the birds without radiographic evidence of ingested shot, 84% of the adult females, 19% of the adult males and 17% of the ducklings had detectable lead concentrations in their blood. Breeding ground exposure of waterfowl to lead shot is unusual and is of particular concern in spectacled eiders because of their threatened status and declining numbers in western Alaska.

Alaska↗
USGS1998

Effect of lead poisoning on spectacled eider survival rates

Spectacled eider ( Somateria fischeri ) populations on the Yukon-Kuskokwim Delta (Y-K Delta), Alaska, declined rapidly through the 1980s, and low adult female survival was suggested as the likely cause of the decline. We used mark-resighting techniques to study annual survival rates of adult female spectacled eiders at 2 sites on the Y-K Delta during 1993-96. Our data suggest survival rates may differ among sites. However, a model fit to a subset of data on females for which we knew lead levels in blood suggests lead exposure influences survival. Adult females exposed to lead prior to hatching their eggs survived at a much lower rate (0.44 ?? 0.10) each year than females not exposed to lead before hatch (0.78 ?? 0.05). We suggest most mortality from lead exposure occurs over winter, and the related reduction in adult survival may be impeding recovery of local populations. We encourage managers to curtail input of lead shot into the environment.

Alaska↗
USGS1998

Foods of Spectacled Eiders Somateria fischeri in the Bering Sea, Alaska

The winter diet of Spectacled Eiders living in marine habitats is known only from two individuals described by Cottam (1939). Here we examine marine diets from 36 stomachs collected near St. Lawrence Island, Bering Sea, Alaska, during May-June in 1987 and 1992. All Spectacled Eiders ate Mollusca, including Gastropoda (snails; frequency of occurrence 20.0%; sole taxon 0.0%) and Bivalvia (bivalves; 80.0%; 48.0%), and Crustacea (barnacles, amphipods and crabs; 30.6%; 0.0%). One bird ate a cod. The predominant species group eaten was Macoma Clams (72.0%; 36.0%). Prey species of Spectacled Eiders occur predominantly in waters 25-60 m deep in the Bering Sea. To obtain these prey, especially the bivalves, on the winter area Spectacled Eiders must forage in waters exceeding 40 m. We speculate that Spectacled Eiders regularly forage at depths of 45-70 m throughout winter.

Alaska↗