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: 3088
Prehistoric Alaska: The land Prehistoric Alaska: The land
Many Alaskans know the dynamic nature of Alaska’s landscape firsthand. The 1964 earthquake, the 1989 eruption of Mount Redoubt volcano, the frequent earthquakes in the Aleutians and the ever-shifting meanders of the Yukon and Kuskokwim rivers remind them of constant changes to the land. These changes are part of the continuing story of the geologic growth and development of Alaska during...
Authors
Frederic H. Wilson, Florence R. Weber
Morphological and genetic divergence among Alaskan populations of Brachyramphus murrelets Morphological and genetic divergence among Alaskan populations of Brachyramphus murrelets
We studied morphological and mitochondrial DNA (mtDNA) divergence among three populations of Brachyramphus Murrelets: Kittlitz's Murrelets (B. brevirostris), and tree-nesting and ground-nesting Marbled Murrelets (B. marmoratus). We found little morphological divergence in external and skeletal measurements among Marbled Murrelets, but both populations were easily distinguished from...
Authors
Jay Pitocchelli, John F. Piatt, Matthew A. Cronin
Phenotypic divergence of secondary sexual traits among sage grouse, Centrocercus urophasianus, populations Phenotypic divergence of secondary sexual traits among sage grouse, Centrocercus urophasianus, populations
Sage grouse, Centrocercus urophasianus, in an isolated montane basin near Gunnison, Colorado differ in several morphological and behavioural traits from conspecifics studied in other areas of the species' range. Both sexes in Gunnison are smaller than sage grouse elsewhere, and males possess differences in feather morphology as well. The mating behaviour of male sage grouse in three...
Authors
Jessica R. Young, Jerry W. Hupp, Jack W. Bradbury, Clait E. Braun
Management of Pacific brant: Population structure and conservation issues Management of Pacific brant: Population structure and conservation issues
Pacific brant (Branta bernicla) nest from the Yukon-Kuskokwim (Y-) Delta in southwestern Alaska along the coast of North America to the central Canadian arctic (Pacific Flyway Subcommittee on Pacific Brant 1992) (Figure 1). Birds from this population also nest in the Canadian arctic islands south of Prince Patrick Island and on the coast of the Chukotka Peninsula. Brant nest principally...
Authors
James S. Sedinger, David H. Ward, R. Michael Anthony, Dirk V. Derksen, Calvin J. Lensink, Karen S. Bollinger, Neil K. Dawe
Assessment of shoreline vegetation in relation to use by molting black brant Branta bernicla nigricans on the Alaska Coastal Plain Assessment of shoreline vegetation in relation to use by molting black brant Branta bernicla nigricans on the Alaska Coastal Plain
To evaluate the importance of large thaw lakes on the Alaska Coastal Plain for molting Pacific black brant Branta bernicla nigricans, distribution and life form of shoreline vegetation were assessed using several scales: satellite imagery, point-intercept transects, cover quadrats, and a parameter for water regime. Brant population and distribution estimates from aerial surveys were used...
Authors
Milton W. Weller, K. C. Jensen, Eric J. Taylor, Mark W. Miller, Karen S. Bollinger, Dirk V. Derksen, Daniel Esler, Carl J. Markon
Succession on regraded placer mine spoil in Alaska, USA, in relation to initial site characteristics Succession on regraded placer mine spoil in Alaska, USA, in relation to initial site characteristics
This study evaluated the rate and pattern of natural succession on regraded placer mine spoil in relation to initial substrate characteristics. The study site was the Glen Creek watershed of the Kantishna mining area of Denali National Park and Preserve, Alaska. After regrading, twelve 0.01-ha plots were established and substrate characteristics were measured. Natural plant succession...
Authors
R.V. Densmore
Emperor goose (Chen canagica) Emperor goose (Chen canagica)
Early naturalists exploring western Alaska were intrigued to find a stocky, blue-gray species of coastal goose unique to that area and nearby Russia. As E. W. Nelson (1887) wrote, "Among the various species of birds more or less peculiar to Alaska this goose is perhaps the most noteworthy." The Emperor Goose nests in the extensive coastal salt marsh habitats of arctic and sub-arctic...
Authors
Margaret R. Petersen, Joel A. Schmutz, R.F. Rockwell
Functional response of wolves preying on barren-ground caribou in a multiple-prey ecosystem Functional response of wolves preying on barren-ground caribou in a multiple-prey ecosystem
1. We investigated the functional response of wolves (Canis lupus) to varying abundance of ungulate prey to test the hypothesis that switching from alternate prey to preferred prey results in regulation of a caribou (Rangifer tarandus) population at low densities. 2. We determined prey selection, kill rates, and prey abundance for four wolf packs during three 30-day periods in March 1989...
Authors
B.W. Dale, Layne G. Adams, R.T. Bowyer
Environmental variability facilitates coexistence within an alcid community at sea Environmental variability facilitates coexistence within an alcid community at sea
We examined coexistence at sea among 7 taxa of diving, wing-propelled seabirds (Alcidae) in the genera Aethia, Uria, Cepphus, and Fratercula. Species abundances were measured simultaneously with a suite of environmental factors in the northern Bering Sea, Alaska, USA; data from 260 adjacent and non-adjacent sites occupied by alcids foraging offshore near breeding colonies were then...
Authors
J. Christopher Haney, Amy E.S. Schauer
The role of nutrient reserves for clutch formation by Northern Pintails in Alaska The role of nutrient reserves for clutch formation by Northern Pintails in Alaska
We analyzed carcass composition of female Northern Pintails (Anas acuta) in Alaska to assess the importance of nutrient reserves for formation of first clutches (n = 85) and renests (n = 39). Habitat (tundra vs. boreal forest), hen age (yearling vs. adult), and year (1990 vs. 1991) did not affect nutrient reserve use. During formation of first clutches, Northern Pintail hens relied on...
Authors
Daniel Esler, J. Barry Grand
Navigating aerial transects with a laptop computer Navigating aerial transects with a laptop computer
SUMMARY: A comparison is made of different methods of determining size of home range from grid trapping data. Studies of artificial populations show that a boundary strip method of measuring area and an adjusted range length give sizes closer to the true range than do minimum area or observed range length methods. In simulated trapping of artificial populations, the known range size
Authors
R. Michael Anthony, R.A. Stehn
Seasonal and annual survival of emperor geese Seasonal and annual survival of emperor geese
Population levels of emperor geese (Chen canagica) in Alaska in 1993 were about half that estimated in the 1960s. Survival information is necessary for managers to decide how to best enhance recovery of this species to former levels. We calculated seasonal and annual estimates of emperor goose survival from resightings of neck-collared birds. Geese were neck collared in 1988-90 on their...
Authors
Joel A. Schmutz, Susan E. Cantor, Margaret R. Petersen