Publications

Systematic ship-board surveys were used to simultaneously record seabird abundances and resolve coarse-scale (3 to 10 km) horizontal and fine-scale (1 to 10 m) vertical variability in water-column structure and bathymetry for portions of the coastal zone in Anadyr Strait near western St. Lawrence Island, northern Bering Sea, Alaska, during August and September 1987. Three plankton-feeding alcids,

Mortality rates of seabirds in the Japanese land-based drift gillnet fishery for salmon were assessed from 413 gillnet sets made by Japanese research vessels in offshore areas used by the commercial fleet. Sixteen species of seabirds were recorded in nets. Shearwaters, primarily Short-tailed Shearwaters (Puffinus tenuirostris), and to a lesser extent Sooty Shearwaters (P. griseus), predominated in

Arctic geese nest in a highly seasonal environment in which ungrazed plants reach peak nitrogen concentrations when goslings hatch (Sedinger and Raveling 1986). Grazing by geese prolongs peak nutrient concentrations but reduces food availability. This should cause nutrient availability to decline seasonally. Here, we test the hypothesis that late-hatching goslings of Black Brant (Branta bernicla n

About 15% of Northern Fulmars (Fulmarus glacialis) breeding on the Semidi Islands in 1979 had light-phase plumage; the remainder were dark. Fulmars of different plumage types mated indiscriminantly, but the lighter member of a mixed pair was more likely to be male than female. Pairs that included at least one light-phase member had lower breeding success than dark/dark pairs in one of six years. C

The foraging behavior of arctic foxes was observed in a waterfowl nesting area on the Yukon–Kuskokwim Delta of Alaska in 1985–1986. Observations were made during peak fox activity from two towers, 3 m high, located in different community types. Data were collected continuously for individual foxes on specific activities, the community in which activities occurred, and the type of food obtained. Af

Tundra vegetation and environmental variables were sampled on the Yukon–Kuskokwim delta in western Alaska. On transects extending from intertidal mudflat to upland tundra, we estimated cover by vascular plant species, soil moisture, salinity, relative elevation, depth to permafrost, and distance upriver from the coast. Two-way indicator species analysis (TWINSPAN) classified 21 communities. Ordina

We employ a line transect method to estimate the density of the common and Pacific loon in the Yukon Flats National Wildlife Refuge from aerial survey data. Line transect methods have the advantage of automatically taking into account “visibility bias” due to detectability difference of animals at different distances from the transect line. However, line transect methods must overcome two difficul

We examined the causes and timing of moose (Alces alces) calf mortality during 1988­ 90 in 2 locations in western interior Alaska. Annual survival rates of all calves in 1988 (0.34, n = 42) and 1989 (0.29, n=47) on the Nowitna National Wildlife Refuge (NWR) and in 1990 (0.25, n = 62) on the Koyukuk NWR were not significantly different. Survival rates of male and female calves were not significantl

Aerial and boat-based surveys for Marbled Murrelets (Brachyramphus marmoratus) were conducted simultaneously over short transect distances (ca. 2 km) in three different areas of the Alexander Archipelago to assess the accuracy and variability of aerial counts compared to boat-based counts. Additional aerial surveys were conducted over a wider geographic area to assess temporal and spatial variabil

Change-in-ratio methods have been developed to estimate the size of populations with two or three population subclasses. Most of these methods require the often unreasonable assumption of equal sampling probabilities for individuals in all subclasses. This paper presents new models based on the weaker assumption that ratios of sampling probabilities are constant over time for populations with thre

A common problem in wildlife law enforcement is identifying the species of origin of carcasses, meat, or blood when morphological characters such as hair or bones are not available. Immunological and protein electrophoretic (allozyme or general protein) procedures have been used in species identification with considerable success (Bunch et al. 1976, McClymont et al. 1982, Wolfe 1983, Mardini 1984,

We assessed mitochondrial DNA variation in North American black bears (Ursus americanus), brown bears (Ursus arctos), and polar bears (Ursus maritimus). Divergent mitochondrial DNA haplotypes (0.05 base substitutions per nucleotide) were identified in populations of black bears from Montana and Oregon. In contrast, very similar haplotypes occur in black bears across North America. This discordance