Publications

We used restriction-enzyme analysis of polymerase-chain reaction-amplified, mitochondrial DNA (mtDNA) to assess genetic differentiation of subspecies and populations of sea otters, Enhydra lutris, throughout the range of the species. There were several haplotypes of mtDNA in each subspecies and geographically separate populations. MtDNA sequence divergence of haplotypes of sea otters was...

Thirty-seven species of shorebirds breed in Alaska, and six overwinter in its subarctic regions. The coastal habitats of Alaska provide critical staging areas during spring and fall migrations; 51 sites qualify within the three categories of shorebird reserves listed by the Western Hemisphere Shorebird Reserve Network (Hemispheric, International and Regional). Studies on Alaskan...

Descriptions of mines, prospects, and mineral occurrences in the Alaska Resource Data File (ARDF) are published for individual U.S. Geological Survey 1:250,000 scale quadrangles in Alaska (see accompanying map) and are available for downloading from USGS World Wide Web site: http://www-rnrs-ak.wr.usgs.gov/ardf. These descriptions are divided into a number of fields which describe...

We studied nesting chronology and success of Northern Pintails (Anas acuta) on the coastal Yukon-Kuskokwim Delta, Alaska during the summers of 1991-1993. We found a total of 795 nests during three annual searches of a 27.4 km2 area. Minimum nest density averaged 9.67 nests per km2. Nesting success varied among years and ranged from 43.12% in 1991 to 10.74% in 1993 (average 23.95%). Most...

We studied survival rates of Northern Pintail (Anas acuta; hereafter pintail) broods and ducklings along the lower Kashunuk River on the Yukon-Kuskokwim Delta, Alaska. Survival rates were determined for 770 ducklings in 111 broods. Brood sizes at hatch were smaller in 1993 versus 1991 and 1992. Duckling survival rates were lower than those reported in previous studies and differed among...

Northern pintails (Anas acuta) are highly nomadic, which may result in high levels of gene flow among nesting areas. To assess the extent of genetic differentiation among nesting areas, we analyzed mitochondrial DNA (mtDNA) variation in northern pintail females from three regions: Alaska, California, and midcontinent prairies and parklands. Abundant mtDNA variation was evident (20...

To produce reliable estimates of the size or vital rates of a given population, it is important that the boundaries of the population under study are clearly defined. This is particularly critical for large, migratory animals where levels of sustainable harvest are based on these estimates, and where small errors may have serious long-term consequences for the population. Once...

Distribution, abundance, and use of arctic fox dens located in coastal tundra communities of the Yukon–Kuskokwim delta were determined in studies from 1985 to 1990. Dens were denser and less complex than those described in studies conducted above the Arctic Circle. Eighty-three dens of varying complexity were found in the 52-km2 study area. Nineteen dens were used by arctic foxes for...

No abstract available.

No abstract available.

To facilitate decisions to classify species according to risk of extinction, we used Bayesian methods to analyze trend data for the Spectacled Eider, an arctic sea duck. Trend data from three independent surveys of the Yukon-Kuskokwim Delta were analyzed individually and in combination to yield posterior distributions for population growth rates. We used classification criteria developed...

An image-processing program developed by the National Institute of Health, IMAGE, was modified in a cooperative project between remote sensing specialists at the Ohio State University Center for Mapping and scientists at the Alaska Science Center to facilitate estimating numbers of black brant (Branta bernicla nigricans) in flocks at Izembek National Wildlife Refuge. The modified program...