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: 3087
Demographic and temporal variations in immunity and condition of polar bears (Ursus maritimus) from the southern Beaufort Sea Demographic and temporal variations in immunity and condition of polar bears (Ursus maritimus) from the southern Beaufort Sea
Assessing the health and condition of animals in their natural environment can be problematic. Many physiological metrics, including immunity, are highly influenced by specific context and recent events to which researchers may be unaware. Thus, using a multifaceted physiological approach and a context-specific analysis encompassing multiple time scales can be highly informative...
Authors
Lorin Neuman-Lee, Patricia Terletzky, Todd C. Atwood, Eric Gese, Geoffrey Smith, Sydney Greenfield, John Pettit, Susannah French
Temporal complexity of southern Beaufort Sea polar bear diets during a period of increasing land use Temporal complexity of southern Beaufort Sea polar bear diets during a period of increasing land use
From 2000 to 2013, use of land as a seasonal habitat by polar bears (Ursus maritimus) of the southern Beaufort Sea (SB) subpopulation substantially increased. This onshore use has been linked to reduced spatial and temporal availability of sea ice, as well as to the availability of subsistence‐harvested bowhead whale (Balaena mysticetus) bone piles. Here, we evaluated the role of climate
Authors
Melissa A. McKinney, Todd C. Atwood, Sara J. Iverson, Elizabeth L. Peacock
Relative influences of climate change and human activity on the onshore distribution of polar bears Relative influences of climate change and human activity on the onshore distribution of polar bears
Climate change is altering habitat for many species, leading to shifts in distributions that can increase levels of human-wildlife conflict. To develop effective strategies for minimizing human-wildlife conflict, we must understand the relative influences that climate change and other factors have on wildlife distributions. Polar bears (Ursus maritimus) are increasingly using land during...
Authors
Ryan H. Wilson, Eric V. Regehr, Michelle St. Martin, Todd C. Atwood, Elizabeth L. Peacock, Susanne Miller, George J. Divoky
Environmental and behavioral changes may influence the exposure of an Arctic apex predator to pathogens and contaminants Environmental and behavioral changes may influence the exposure of an Arctic apex predator to pathogens and contaminants
Recent decline of sea ice habitat has coincided with increased use of land by polar bears (Ursus maritimus) from the southern Beaufort Sea (SB), which may alter the risks of exposure to pathogens and contaminants. We assayed blood samples from SB polar bears to assess prior exposure to the pathogens Brucella spp., Toxoplasma gondii, Coxiella burnetii, Francisella tularensis, and Neospora...
Authors
Todd C. Atwood, Colleen G. Duncan, Kelly A. Patyk, Pauline Nol, Jack Rhyan, Matthew McCollum, Melissa A. McKinney, Andrew M. Ramey, Camila Cerqueira-Cezar, Oliver C H Kwok, Jitender P Dubey, S.G. Hennager
Polar bear attacks on humans: Implications of a changing climate Polar bear attacks on humans: Implications of a changing climate
Understanding causes of polar bear (Ursus maritimus) attacks on humans is critical to ensuring both human safety and polar bear conservation. Although considerable attention has been focused on understanding black (U. americanus) and grizzly (U. arctos) bear conflicts with humans, there have been few attempts to systematically collect, analyze, and interpret available information on...
Authors
James Wilder, Dag Vongraven, Todd C. Atwood, Bob Hansen, Amalie Jessen, Anatoly A. Kochnev, Geoff York, Rachel Vallender, Daryll Hedman, Melissa Gibbons
Movements and habitat use of White-fronted Geese (Anser albifrons frontalis) during the remigial molt in arctic Alaska, USA Movements and habitat use of White-fronted Geese (Anser albifrons frontalis) during the remigial molt in arctic Alaska, USA
Proposed oil and gas leasing in the National Petroleum Reserve - Alaska has raised questions about possible impacts of development on molting Greater White-fronted Geese (Anser albifrons frontalis) and their habitats. We used GPS transmitters to record fine-scale location data of molting and post-molt White-fronted Geese to assess patterns of movement and resource selection relative to...
Authors
Paul L. Flint, Brandt W. Meixell
Best practices for assessing forage fish fisheries-seabird resource competition Best practices for assessing forage fish fisheries-seabird resource competition
Worldwide, in recent years capture fisheries targeting lower-trophic level forage fish and euphausiid crustaceans have been substantial (∼20 million metric tons [MT] annually). Landings of forage species are projected to increase in the future, and this harvest may affect marine ecosystems and predator-prey interactions by removal or redistribution of biomass central to pelagic food webs...
Authors
William J. Sydeman, Sarah Ann Thompson, Tycho Anker-Nilssen, Mayumi L. Arimitsu, Ashley Bennison, Sophie Bertrand, Philipp Boersch-Supan, Charlotte Boyd, Nicole C. Bransome, Robert J.M. Crawford, Francis Daunt, Robert W. Furness, Dimas Gianuca, Amanda Gladics, Laura Koehn, Jennifer W. Lang, Elizabeth Loggerwell, Taryn L. Morris, Elizabeth M. Phillips, Jennifer Provencher, Andre E. Punt, Claire Saraux, Lynne Shannon, Richard B. Sherley, Alejandro Simeone, Ross M. Wanless, Sarah Wanless, Stephani Zador
Surveillance for highly pathogenic influenza A viruses in California during 2014–2015 provides insights into viral evolutionary pathways and the spatiotemporal extent of viruses in the Pacific Americas Flyway Surveillance for highly pathogenic influenza A viruses in California during 2014–2015 provides insights into viral evolutionary pathways and the spatiotemporal extent of viruses in the Pacific Americas Flyway
We used surveillance data collected in California before, concurrent with, and subsequent to an outbreak of highly pathogenic (HP) clade 2.3.4.4 influenza A viruses (IAVs) in 2014–2015 to (i) evaluate IAV prevalence in waterfowl, (ii) assess the evidence for spill-over infections in marine mammals and (iii) genetically characterize low-pathogenic (LP) and HP IAVs to refine inference on...
Authors
Andrew M. Ramey, Nichola J. Hill, Troy Cline, Magdalena Plancarte, Susan De La Cruz, Michael L. Casazza, Joshua T. Ackerman, Joseph P. Fleskes, T. Winston Vickers, Andrew B. Reeves, Frances Gulland, Christine Fontaine, Diann J. Prosser, Jonathan Runstadler, Walter M. Boyce
Harvesting wildlife affected by climate change: a modelling and management approach for polar bears Harvesting wildlife affected by climate change: a modelling and management approach for polar bears
The conservation of many wildlife species requires understanding the demographic effects of climate change, including interactions between climate change and harvest, which can provide cultural, nutritional or economic value to humans.We present a demographic model that is based on the polar bear Ursus maritimus life cycle and includes density-dependent relationships linking vital rates...
Authors
Eric V. Regehr, Ryan H. Wilson, Karyn D. Rode, Michael C. Runge, Harry Stern
Glacial conditioning of stream position and flooding in the braid plain of the Exit Glacier foreland, Alaska Glacial conditioning of stream position and flooding in the braid plain of the Exit Glacier foreland, Alaska
Flow spilling out of an active braid plain often signals the onset of channel migration or avulsion to previously occupied areas. In a recently deglaciated environment, distinguishing between shifts in active braid plain location, considered reversible by fluvial processes at short timescales, and more permanent glacier-conditioned changes in stream position can be critical to...
Authors
Janet H. Curran, Michael G. Loso, Haley B. Williams
Effects of surgically implanted transmitters on reproduction and survival in mallards Effects of surgically implanted transmitters on reproduction and survival in mallards
Abdominally implanted radiotransmitters have been widely used in studies of waterbird ecology; however, the longer handling times and invasiveness of surgical implantation raise important concerns about animal welfare and potential effects on data quality. Although it is difficult to assess effects of handling and marking wild animals by comparing them with unmarked controls, insights...
Authors
Jennifer Sheppard, Todd W. Arnold, Courtney L. Amundson, David Klee
Neotectonics of interior Alaska and the late Quaternary slip rate along the Denali fault system Neotectonics of interior Alaska and the late Quaternary slip rate along the Denali fault system
The neotectonics of southern Alaska (USA) are characterized by a several hundred kilometers–wide zone of dextral transpressional that spans the Alaska Range. The Denali fault system is the largest active strike-slip fault system in interior Alaska, and it produced a Mw 7.9 earthquake in 2002. To evaluate the late Quaternary slip rate on the Denali fault system, we collected samples for...
Authors
Peter J. Haeussler, Ari Matmon, David P. Schwartz, Gordon G. Seitz