Publications
USGS research activities relevant to Alaska have yielded more than 9400 historical publications. This page features some of the most recent newsworthy research findings.
Filter Total Items: 3110
Survival and pre-fledging body mass in juvenile emperor geese Survival and pre-fledging body mass in juvenile emperor geese
A positive relationship exists between fledgling body mass and juvenile survival for some altricial (Krementz et al. 1989, Magrath 1991, Linden et al. 1992) and precocial (Owen and Black 1989, Longcore et al. 1991, Francis et al. 1992) species. Because the energetic demands of migration are high, physiologic condition may be a proximate determinate of juvenile survival in geese. Owen and...
Authors
Joel A. Schmutz
Distribution and abundance of Marbled Murrelets in Alaska Distribution and abundance of Marbled Murrelets in Alaska
Most seabirds breed in colonies on offshore islands, but throughout most of their range from California to Alaska Marbled Murrelets (Brachyramphus marmoratus) fly inland to nest on trees in old-growth coniferous forests. Some fraction of the murrelet population nests on the ground in Alaska. The relative distribution and abundance of murrelets in forested and treeless areas of Alaska is...
Authors
John F. Piatt, R. Glenn Ford
Sex identification of polar bears from blood and tissue samples Sex identification of polar bears from blood and tissue samples
Polar bears (Ursus maritimus) can be adversely affected by hunting and other human perturbations because of low population densities and low reproduction rates. The sustainable take of adult females may be as low as 1.5% of the population. Females and accompanying young are most vulnerable to hunting, and hunters have not consistently reported the sex composition of the harvest...
Authors
Steven C. Amstrup, G.W. Garner, M. A. Cronin, J.C. Patton
Conservation genetics of managed ungulate populations Conservation genetics of managed ungulate populations
Natural populations of many species are increasingly impacted by human activities. Perturbations are particularly pronunced for large ungulates due in part to sport and commercial harvest, to reductions and fragmentation of native habitat, and as the result of reintroductions. These perturbations affect population size, sex and age composition, and population breeding structure, and as a
Authors
Kim T. Scribner
Chiricahua Peak quadrangle, Cochise County, Arizona: Analytic data and geologic sample catalog Chiricahua Peak quadrangle, Cochise County, Arizona: Analytic data and geologic sample catalog
No abstract available.
Authors
Edward A. du Bray, Douglas B. Yager, John S. Pallister
Massive sulfide metallogenesis at a late Mesozoic sediment-covered spreading axis: Evidence from the Franciscan complex and contemporary analogues Massive sulfide metallogenesis at a late Mesozoic sediment-covered spreading axis: Evidence from the Franciscan complex and contemporary analogues
The Island Mountain deposit, an anomalous massive sulfide in the Central belt of the Franciscan subduction complex, northern California Coast Ranges, formed during hydrothermal activity in a sediment-dominated paleo-sea-floor environment. Although the base of the massive sulfide is juxtaposed against a 500-m-wide melange band, its gradational upper contact within a coherent sequence of...
Authors
Randolph A. Koski, Roberta C. Lamons, Julie A. Dumoulin, Robin M. Bouse
Kappa-casein polymorphisms among cattle breeds and bison herds Kappa-casein polymorphisms among cattle breeds and bison herds
We identified the HindIII restriction site polymorphism of K-casein in cattle reported by Pinder et al. (Animal Genetics 22, 11, 1991) and found an additonal polymorphism (RsaI) in cattle and bison. The HindIII and RsaI restriction sites were mapped and three haplotypes (alleles) were identified. Preliminary screening of 39 cattle and 71 bison revealed one allele restricted to cattle...
Authors
M. A. Cronin, N. Cockett
In my experience: Mitochondrial DNA in wildlife taxonomy and conservation biology: Cautionary notes In my experience: Mitochondrial DNA in wildlife taxonomy and conservation biology: Cautionary notes
Several recently published papers discussed the importance of systematics (the study of evolutionary and genetic relationships among organisms) and taxonomy (the naming and classification of organisms) for managing wildlife (Ryder 1986, Avise 1989, Amato 1991, O'Brien and Mayr 1991, Dowling et al. 1992), Often, classification below the species level is needed; for example, the Endangered...
Authors
Matthew A. Cronin
Age-specific reproduction in female sea otters (Enhydra lutris) from south-central Alaska: Analysis of reproductive tracts Age-specific reproduction in female sea otters (Enhydra lutris) from south-central Alaska: Analysis of reproductive tracts
We estimated age at sexual maturity and age-specific reproductive rates by examining carcasses and reproductive tracts from 177 female sea otters (Enhydra lutris). Carcasses were recovered from south-central Alaska, Primarily from western Prince William Sound, as a result of the T/V Exxon Valdez oil spill in 1989. We found 65% of our sample to be sexually mature. Sexual maturity was...
Authors
James L. Bodkin, Daniel M. Mulcahy, Calvin J. Lensink
Annual and Spatial Variation of the Kelp Forest Fish Assemblage at San Nicolas Island, California Annual and Spatial Variation of the Kelp Forest Fish Assemblage at San Nicolas Island, California
The kelp forest fishes of San Nicolas Island, California were studied from 1981-1986 to examine the causes of among-site and among-year variation in the fish assemblages. Fish counts and seven physical and biological variables were recorded at six sites around the island every spring and fall. Over the study period, a total of 45 fish species from 18 families were recorded, though...
Authors
R.J. Cowen, James L. Bodkin
Seabirds of the central North Pacific Seabirds of the central North Pacific
No abstract available.
Authors
P.J. Gould, John F. Piatt
Losses of seabirds in gill nets in the North Pacific Losses of seabirds in gill nets in the North Pacific
Existing knowledge on high-seas and coastal gillnet fisheries known to kill seabirds in the North Pacific is summarized. Recent estimates suggest that high-seas gillnet fisheries may have taken more than 500,000 seabirds in 1990. The majority of birds taken in those fisheries were Sooty Puffinus griseus or Short-tailed P. tenuirostris shearwaters. A recent analysis of impacts of those...
Authors
Anthony R. DeGange, Robert H. Day, Jean E. Takekawa, Vivian M. Mendenhall