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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

Liverworts from Attu Island, Near Islands, Aleutian Islands, Alaska (USA) with comparison to the Commander Islands (Russia)

The liverwort flora of Attu Island, the westernmost Aleutian Island in the United States, was studied to assess species diversity in the hyperoceanic sector of the northern boreal subzone. The field study was undertaken in sites selected to represent a spectrum of environmental variation, primarily within the eastern part of the island. Data were analyzed using our own collections on Attu Island,
Authors
Stephen S. Talbot, Wilfred B. Schofield, Jiří Váňa, Sandra L. Talbot

Nesting ecology of a naturalized population of Mallards Anas platyrhynchos in New Zealand

Investigating the reproductive ecology of naturalized species provides insights into the role of the source population's characteristics vs. post‐release adaptation that influence the success of introduction programmes. Introduced and naturalized Mallards Anas platyrhynchos are widely established in New Zealand (NZ), but little is known regarding their reproductive ecology. We evaluated the nestin
Authors
Jennifer L. Sheppard, Courtney L. Amundson, Todd W. Arnold, David Klee

Sex-specific variation in denning by brown bears

Denning characteristics of brown bears (Ursus arctos) have been described in numerous studies; however, population specific factors (i.e., landscape characteristics and climate) can greatly influence the location and timing of denning. Our objective was to evaluate den-site characteristics and denning chronology for male and female brown bears in Lake Clark National Park and Preserve, Alaska. We u
Authors
Lindsey Mangipane, Jerrold L. Belant, Buck Mangipane, David Gustine, Grant V. Hilderbrand

Pliocene erosional pulse and glacier-landscape feedbacks in the western Alaska Range

Pliocene–Pleistocene glaciation modified the topography and erosion of most middle- and high-latitude mountain belts, because the evolution of catchment topography controls long-term glacier mass balance and erosion. Hence, characterizing how erosion rates change during repeated glaciations can help test hypothesized glacier erosion-landscape feedbacks across a range of settings. To better underst
Authors
Richard O. Lease

Landscape genetics identifies streams and drainage infrastructure as dispersal corridors for an endangered wetland bird

Anthropogenic alterations to landscape structure and composition can have significant impacts on biodiversity, potentially leading to species extinctions. Population‐level impacts of landscape change are mediated by animal behaviors, in particular dispersal behavior. Little is known about the dispersal habits of rails (Rallidae) due to their cryptic behavior and tendency to occupy densely vegetate
Authors
Charles B. van Rees, J. Michael Reed, Robert E. Wilson, Jared G. Underwood, Sarah A. Sonsthagen

Climate change and future wildfire in the western USA: An ecological approach to nonstationarity

We developed ecologically based climate‐fire projections for the western United States. Using a finer ecological classification and fire‐relevant climate predictors, we created statistical models linking climate and wildfire area burned for ecosections, which are geographic delineations based on biophysical variables. The results indicate a gradient from purely fuel‐limited (antecedent positive wa
Authors
Jeremy S. Littell, Donald McKenzie, Ho Yi Wan, Samuel A. Cushman

Lactation and resource limitation affect stress responses, thyroid hormones, immune function, and antioxidant capacity of sea otters (Enhydra lutris)

Lactation is the most energetically demanding stage of reproduction in female mammals. Increased energetic allocation toward current reproduction may result in fitness costs, although the mechanisms underlying these trade‐offs are not well understood. Trade‐offs during lactation may include reduced energetic allocation to cellular maintenance, immune response, and survival and may be influenced by
Authors
Sarah M. Chinn, Daniel Monson, M. Tim Tinker, Michelle M. Staedler, Daniel E. Crocker

Development of on-shore behavior among polar bears (Ursus maritimus) in the southern Beaufort Sea: Inherited or learned?

Polar bears (Ursus maritimus) are experiencing rapid and substantial changes to their environment due to global climate change. Polar bears of the southern Beaufort Sea (SB) have historically spent most of the year on the sea ice. However, recent reports from Alaska indicate that the proportion of the SB subpopulation observed on-shore during late summer and early fall has increased. Our objective
Authors
K. M. Lillie, E. M. Gese, Todd C. Atwood, Sarah A. Sonsthagen

Biogeography of pelagic food webs in the North Pacific

The tufted puffin (Fratercula cirrhata) is a generalist seabird that breeds throughout the North Pacific and eats more than 75 different prey species. Using puffins as samplers, we characterized the geographic variability in pelagic food webs across the subarctic North Pacific from the composition of ~10,000 tufted puffin meals (~56,000 prey items) collected at 35 colonies in the Gulf of Alaska (G
Authors
John F. Piatt, Mayumi L. Arimitsu, William J. Sydeman, Sarah Ann Thompson, Heather Renner, Stephani Zador, David C. Douglas, Scott A. Hatch, Arthur B. Kettle, Jeffrey C. Williams

Comparative nest survival of three sympatric loon species breeding in the Arctic

Identifying factors influencing nest survival among sympatric species is important for understanding and managing sources of variation in population dynamics of individual species. Three species of loons nest sympatrically in northern Alaska and differ in body size, life history characteristics, and population trends. We tested the effects of competition, nest site selection, and water level varia
Authors
Brian D. Uher-Koch, Joshua C. Koch, Kenneth G. Wright, Joel A. Schmutz

Influence of landscape structure, topography, and forest type on spatial variation in historical fire regimes, central Oregon, USA

Context In the interior Northwest, debate over restoring mixed-conifer forests after a century of fire exclusion is hampered by poor understanding of the pattern and causes of spatial variation in historical fire regimes. Objectives To identify the roles of topography, landscape structure, and forest type in driving spatial variation in historical fire regimes in mixed-conifer forests of centr
Authors
Andrew Merschel, Emily K. Heyerdahl, Thomas A. Spies, Rachel A. Loehman

Effect of climate change on disease spread in wildlife

A growing body of evidence indicates that climate change alone, or acting synergistically with current anthropogenic threats, is affecting the health of wild populations of aquatic and terrestrial wildlife. Measurable by-products of climate change include elevated atmospheric concentrations of greenhouse gases, higher average global temperatures; variations in global precipitation patterns, rising
Authors
Erik K. Hofmeister, Caroline R. Van Hemert