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: 3107
Otters Otters
The otters (Mustelidae; Lutrinae) provide a unique look into the evolution of marine living by mammals. This is because most extant marine mammals have been so highly modified by long periods of selection for life in the sea that they bare little resemblance to their terrestrial ancestors. Marine otters, by contrast, are recent expatriates from terrestrial and freshwater habitats, and...
Authors
James A. Estes, James L. Bodkin
A new population of Aleutian shield fern (Polystichum aleuticum C. Christens.) on Adak Island, Alaska A new population of Aleutian shield fern (Polystichum aleuticum C. Christens.) on Adak Island, Alaska
We report and describe a new population of the endangered Aleutian shield fern (Polystichum aleuticum C. Christens.) discovered on Mount Reed, Adak Island, Alaska. The new population is located at a lower elevation than the other known populations, placing the species' known elevational range between 338 m and 525 m. The discovery of this population is significant because it increases...
Authors
Sandra L. Talbot, Stephen S. Talbot
Snow geese Snow geese
Part of the coastal plain of the Arctic National Wildlife Refuge, Alaska, is used as an autumn staging area by lesser snow geese (Chen caerulescens caerulescens) from the Western Canadian Arctic population (hereafter called the Western Arctic population). There were approximately 200,000 breeding adults in the Western Arctic population through the mid-1980s (Johnson and Herter 1989), but...
Authors
Jerry W. Hupp, Donna G. Robertson, Alan W. Brackney
Life-history implications of large-scale spatial variation in adult survival of black brant (Branta bernicla nigricans) Life-history implications of large-scale spatial variation in adult survival of black brant (Branta bernicla nigricans)
We used capture-recapture methods to estimate adult survival rates for adult female Black Brant (Branta bernicla nigricans; hereafter “brant”) from three colonies in Alaska, two on the Yukon-Kuskokwim Delta, and one on Alaska's Arctic coast. Costs of migration and reproductive effort varied among those colonies, enabling us to examine variation in survival in relation to variation in...
Authors
James S. Sedinger, Nathan Chelgren, Mark S. Lindberg, Tim Obritchkewitch, Morgan T. Kirk, Philip D. Martin, Betty A. Anderson, David H. Ward
Genetic parentage and mate guarding in the Arctic-breedng Western Sandpiper Genetic parentage and mate guarding in the Arctic-breedng Western Sandpiper
Extrapair copulations and fertilizations are common among birds, especially in passerines. So far, however, few studies have examined genetic mating systems in socially monogamous shorebirds. Here, we examine parentage in the Western Sandpiper (Calidris mauri). Given that Western Sandpipers nest at high densities on the Arctic tundra, have separate nesting and feeding areas, and show...
Authors
D. Blomqvist, Bart Kempenaers, Richard B. Lanctot, B. K. Sandercock
Muskoxen Muskoxen
Muskoxen (Ovibos moschatus) disappeared from Alaska in the late 1800s, but returned to the Arctic National Wildlife Refuge when animals were reestablished into areas of former range in 1969-1970 (Klein 1988). Released at Barter Island (Kaktovik) and the Kavik River, muskoxen initially moved into regions that encompassed the 1002 Area on the coastal plain of the Arctic Refuge. From 1974...
Authors
Patricia E. Reynolds, Kenneth J. Wilson, David R. Klein
Fault structure and kinematics of the Long Valley Caldera region, California, revealed by high-accuracy earthquake hypocenters and focal mechanism stress inversions Fault structure and kinematics of the Long Valley Caldera region, California, revealed by high-accuracy earthquake hypocenters and focal mechanism stress inversions
We have determined high-resolution hypocenters for 45,000+ earthquakes that occurred between 1980 and 2000 in the Long Valley caldera area using a double-difference earthquake location algorithm and routinely determined arrival times. The locations reveal numerous discrete fault planes in the southern caldera and adjacent Sierra Nevada block (SNB). Intracaldera faults include a series of...
Authors
Stephanie G. Prejean, William L. Ellsworth, Mark Zoback, Felix Waldhauser
Population genetic structure in Lahontan cutthroat trout Population genetic structure in Lahontan cutthroat trout
We used 10 microsatellite loci to examine the genetic population structure of cutthroat trout Oncorhynchus clarki within the Lahontan Basin complex. Genetic diversity was analyzed for trout from Nevada, California, and Utah representing three putative subspecies: Lahontan O. c. henshawi, Paiute O. c. seleniris, and Humboldt (an unnamed subspecies) cutthroat trout. We found significant...
Authors
Jennifer L. Nielsen, George K. Sage
Educational background and professional participation by federal wildlife biologists: Implications for science, management, and The Wildlife Society Educational background and professional participation by federal wildlife biologists: Implications for science, management, and The Wildlife Society
Over 2,000 people are employed in wildlife biology in the United States federal government. The size of this constituency motivated me to examine the amount of formal education federal biologists have received and the extent of continuing education they undertake by reading journals or attending scientific meetings. Most federal biologists who are members of The Wildlife Society (TWS)...
Authors
Joel A. Schmutz
Lichens from Simeonof Wilderness, Shumagin Island, Southwestern Alaska Lichens from Simeonof Wilderness, Shumagin Island, Southwestern Alaska
One hundred eighty-eight taxa of lichens are reported from Simeonof Island in the Shumagin Islands of southwestern Alaska. Wide-ranging arctic-alpine and boreal species dominate the lichens; a coastal element is moderately represented, while amphi-Beringian species form a minor element. The lichen component of Empetrum nigrum dwarf shrub heath, the dominant vegetation type, was analyzed...
Authors
Stephen S. Talbot, Sandra L. Talbot, J.W. Thomson, F.J.A. Daniels, W.B. Schofield
Blood selenium concentrations and enzyme activities related to glutathione metabolism in wild emperor geese Blood selenium concentrations and enzyme activities related to glutathione metabolism in wild emperor geese
In 1998, we collected blood samples from 63 emperor geese (Chen canagica) on their breeding grounds on the Yukon-Kuskokwim Delta (YKD) in western Alaska, USA. We studied the relationship between selenium concentrations in whole blood and the activities of glutathione peroxidase and glutathione reductase in plasma. Experimental studies have shown that plasma activities of these enzymes...
Authors
J. Christian Franson, David J. Hoffman, Joel A. Schmutz