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: 2889
Using effort information with change-in-ratio data for population estimation
Most change-in-ratio (CIR) methods for estimating fish and wildlife population sizes have been based only on assumptions about how encounter probabilities vary among population subclasses. When information on sampling effort is available, it is also possible to derive CIR estimators based on assumptions about how encounter probabilities vary over time. This paper presents a generalization of previ
Authors
Mark S. Udevitz, Kenneth H. Pollock
Movements of a polar bear from northern Alaska to northern Greenland
Using satellite telemetry, we monitored the movements of an adult female polar bear (Ursus maritimus) as she traveled from the Alaskan Beaufort Sea coast to northern Greenland. She is the first polar bear known to depart the Beaufort Sea region for an extended period, and the first polar bear known to move between Alaska and Greenland. This bear traveled for four months across the polar basin and
Authors
George M. Durner, Steven C. Amstrup
Water over the bridge
The March-April issue of American Scientist contains a commentary by Julia K. Parrish and P. Dee Boersma (Macroscope, "Muddy Waters") that purports to "assess the validity of the claims made concerning seabird mortality as a result of the [Exxon Valdez oil] spill." Parrish and Boersma would have us believe that estimates of seabird mortality made in 1990 by myself and colleagues were exaggerated a
Authors
John F. Piatt
Lead poisoning of spectacled eiders (Somateria fischeri) and of a common eider (Somateria mollissima) in Alaska
Lead poisoning was diagnosed in four spectacled eiders (Somateria fischeri) and one common eider (Somateria mollissima) found dead or moribund at the Yukon Delta National Wildlife Refuge, Alaska (USA) in 1992, 1993, and 1994. Ingested lead shot was found in the lower esophagus of one spectacled eider and in the gizzard of the common eider. Lead concentrations in the livers of the spectacled eiders
Authors
J. Christian Franson, Margaret R. Petersen, Carol U. Meteyer, Milton R. Smith
Movements, distribution, and population dynamics of polar bears in the Beaufort Sea
No abstract available.
Authors
Steven C. Amstrup
Kodiak brown bears
Brown bears (Ursus arctos middendorffi) on the Kodiak Archipelago are famous for their large size and seasonal concentrations at salmon streams. Sport hunting of Kodiak bears has been popular since World War II. Their value as captivating subjects to observe or photograph is a more recent development that is increasing rapidly; visitors from around the world come to experience brown bears on Kodia
Authors
Victor G. Barnes, Roger B. Smith, Mark S. Udevitz, J.R. Bellinger
Automated counting of waterfowl with image processing
No abstract available.
Authors
D.J. Cunningham, W.H. Anderson, R.M. Anthony
Locating waterfowl observations on aerial surveys
We modified standard aerial survey data collection to obtain the geographic location for each waterfowl observation on surveys in Alaska during 1987-1993. Using transect navigation with CPS (global positioning system), data recording on continuously running tapes, and a computer data input program, we located observations with an average deviation along transects of 214 m. The method provided flex
Authors
W.I. Butler, J.I. Hodges, R.A. Stehn
GIS for mapping waterfowl density and distribution from aerial surveys
We modified standard aerial survey data collection to obtain the geographic location for each waterfowl observation on surveys in Alaska during 1987-1993. Using transect navigation with CPS (global positioning system), data recording on continuously running tapes, and a computer data input program, we located observations with an average deviation along transects of 214 m. The method provided flex
Authors
W.I. Butler, R.A. Stehn, G.R. Balogh
Population differentiation in Pacific salmon: local adaptation, genetic drift, or the environment?
Morphological, behavioral, and life-history differences between
Pacific salmon (Oncorhynchus spp.) populations are commonly thought to
reflect local adaptation, and it is likewise common to assume that salmon
populations separated by small distances are locally adapted. Two
alternatives to local adaptation exist: random genetic differentiation
owing to genetic drift and founder events, a
Authors
Milo D. Adkison
Black bear damage to lodgepole pine in central Oregon
Black bear damage to 108 lodgepole pine trees was found in mixed
conifer habitat in central Oregon. No trees of three other conifer
species were injured. Eighty-nine percent of the damage occurred in
the same year. Nearly 20% of the freshly damaged trees had bark
removed from more than 75% of the circumference and, judging from the
fate of trees damaged in prior years, pro
Authors
V.G. Barnes, R.M. Engeman
Vegetation management for reducing mortality of ponderosa pine seedlings from Thomomys spp
The effects of vegetation management on Mazama pocket gopher activity and damage to ponderosa pine seedlings were studied using atrazine herbicide to alter the habitat. Atrazine treatments were applied to a large treatment unit and observed effects were compared to an untreated control unit. The greatly reduced forb and grass cover on the treated unit was associated with a corresponding decrease i
Authors
Richard M. Engeman, Victor G. Barnes, Richard M. Anthony, Heather W. Krupa