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: 2891
An isotopic approach to measuring nitrogen balance in caribou
Nutritional restrictions in winter may reduce the availability of protein for reproduction and survival in northern ungulates. We refined a technique that uses recently voided excreta on snow to assess protein status in wild caribou (Rangifer tarandus) in late winter. Our study was the first application of this non‐invasive, isotopic approach to assess protein status of wild caribou by determining
Authors
David D. Gustine, Perry S. Barboza, Layne G. Adams, Richard G. Farnell, Katherine L. Parker
Using a genetic mixture model to study phenotypic traits: Differential fecundity among Yukon river Chinook Salmon
Fecundity is a vital population characteristic that is directly linked to the productivity of fish populations. Historic data from Yukon River (Alaska) Chinook salmon Oncorhynchus tshawytscha suggest that length‐adjusted fecundity differs among populations within the drainage and either is temporally variable or has declined. Yukon River Chinook salmon have been harvested in large‐mesh gill‐net fi
Authors
Jeffrey F. Bromaghin, D.F. Evenson, T.H. McLain, Blair G. Flannery
Polar bear population status in the northern Beaufort Sea, Canada, 1971-2006
Polar bears (Ursus maritimus) of the northern Beaufort Sea (NB) population occur on the perimeter of the polar basin adjacent to the northwestern islands of the Canadian Arctic Archipelago. Sea ice converges on the islands through most of the year. We used open-population capture–recapture models to estimate population size and vital rates of polar bears between 1971 and 2006 to: (1) assess relati
Authors
I. Stirling, T. L. McDonald, E.S. Richardson, E.V. Regehr, Steven C. Amstrup
Stopover habitats of spring migrating surf scoters in southeast Alaska
Habitat conditions and nutrient reserve levels during spring migration have been suggested as important factors affecting population declines in waterfowl, emphasizing the need to identify key sites used during spring and understand habitat features and resource availability at stopover sites. We used satellite telemetry to identify stopover sites used by surf scoters migrating through southeast A
Authors
Erica K. Lok, Daniel Esler, John Y. Takekawa, S.W. De La Cruz, Boyd W. Sean, D.R. Nysewander, J.R. Evenson, David H. Ward
Egg size matching by an intraspecific brood parasite
Avian brood parasitism provides an ideal system with which to understand animal recognition and its affect on fitness. This phenomenon of laying eggs in the nests of other individuals has classically been framed from the perspective of interspecific brood parasitism and host recognition of parasitic eggs. Few examples exist of strategies adopted by intraspecific brood parasites to maximize success
Authors
Patrick R. Lemons, James S. Sedinger
Interspecies transmission and limited persistence of low pathogenic avian influenza genomes among Alaska dabbling ducks
The reassortment and geographic distribution of low pathogenic avian influenza (LPAI) virus genes are well documented, but little is known about the persistence of intact LPAI genomes among species and locations. To examine persistence of entire LPAI genome constellations in Alaska, we calculated the genetic identities among 161 full-genome LPAI viruses isolated across 4 years from five species of
Authors
Andrew B. Reeves, John M. Pearce, Andrew M. Ramey, Brandt W. Meixell, J.A. Runstadler
Long-term increases in young-of-the-year growth of Arctic cisco Coregonus autumnalis and environmental influences
Arctic cisco Coregonus autumnalis young‐of‐year (YOY) growth was used as a proxy to examine the long‐term response of a high‐latitude fish population to changing climate from 1978 to 2004. YOY growth increased over time (r2 = 0·29) and was correlated with monthly averages of the Arctic oscillation index, air temperature, east wind speed, sea‐ice concentration and river discharge with and without t
Authors
Vanessa R. von Biela, Christian E. Zimmerman, L.L. Moulton
Intercolony variation in growth of black brant goslings on the Yukon-Kuskokwim Delta, Alaska
Recent declines in black brant (Branta bernicla nigricans) are likely the result of low recruitment. In geese, recruitment is strongly affected by habitat conditions experienced by broods because gosling growth rates are indicative of forage conditions during brood rearing and strongly influence future survival and productivity. In 2006–2008, we studied gosling growth at 3 of the 4 major colonies
Authors
T.F. Fondell, Paul L. Flint, J.S. Sedinger, C.A. Nicolai, J.L. Schamber
Estimating carcass persistence and scavenging bias in a human‐influenced landscape in western Alaska
We examined variation in persistence rates of waterfowl carcasses placed along a series of transects in tundra habitats in western Alaska. This study was designed to assess the effects of existing tower structures and was replicated with separate trials in winter, summer and fall as both the resident avian population and the suite of potential scavengers varied seasonally. Carcass persistence rat
Authors
Paul L. Flint, Ellen W. Lance, Kristine M. Sowl, Tyrone F. Donnelly
Two mechanisms of aquatic and terrestrial habitat change along an Alaskan Arctic coastline
Arctic habitats at the interface between land and sea are particularly vulnerable to climate change. The northern Teshekpuk Lake Special Area (N-TLSA), a coastal plain ecosystem along the Beaufort Sea in northern Alaska, provides habitat for migratory waterbirds, caribou, and potentially, denning polar bears. The 60-km coastline of N-TLSA is experiencing increasing rates of coastline erosion and s
Authors
Christopher D. Arp, Benjamin M. Jones, Joel A. Schmutz, Frank E. Urban, M. Torre Jorgenson
Development of monitoring protocols to detect change in rocky intertidal communities of Glacier Bay National Park and Preserve
Glacier Bay National Park and Preserve in southeastern Alaska includes extensive coastlines representing a major proportion of all coastlines held by the National Park Service. The marine plants and invertebrates that occupy intertidal shores form highly productive communities that are ecologically important to a number of vertebrate and invertebrate consumers and that are vulnerable to human dist
Authors
Gail V. Irvine
Re-analysis of Alaskan benchmark glacier mass-balance data using the index method
At Gulkana and Wolverine Glaciers, designated the Alaskan benchmark glaciers, we re-analyzed and re-computed the mass balance time series from 1966 to 2009 to accomplish our goal of making more robust time series. Each glacier's data record was analyzed with the same methods. For surface processes, we estimated missing information with an improved degree-day model. Degree-day models predict ablati
Authors
Ashely E. Van Beusekom, Shad R. O'Nell, Rod S. March, Louis C. Sass, Leif H. Cox