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: 3110
Evaluating methods to assess the body condition of female polar bears Evaluating methods to assess the body condition of female polar bears
An animal's body condition provides insight into its health, foraging success, and overall fitness. Measures of body composition including proportional fat content are useful indicators of condition. Isotopic dilution is a reliable non-destructive method for estimating the body composition of live mammals, but can require prolonged handling times. Alternatively, bioelectrical impedance...
Authors
Anthony M. Pagano, Karyn D. Rode, Stephen N. Atkinson
Tectonic evolution of the Central Andean Plateau and implications for the growth of plateaus Tectonic evolution of the Central Andean Plateau and implications for the growth of plateaus
Current end-member models for the geodynamic evolution of orogenic plateaus predict (a) slow and steady rise during crustal shortening and ablative subduction (i.e., continuous removal) of the lower lithosphere or (b) rapid surface uplift following shortening, which is associated with punctuated removal of dense lower lithosphere and/or lower crustal flow. This review integrates results...
Authors
Carmala N. Garzione, Nadine McQuarrie, Nicholas D. Perez, Todd A. Ehlers, Susan L. Beck, Nandini Kar, Nathan Eichelberger, Alan D. Chapman, Kevin M. Ward, Mihai N. Ducea, Richard O. Lease, Christopher J. Poulsen, Lara S. Wagner, Joel E. Saylor, George Zandt, Brian K. Horton
Possible behavioural, energetic and demographic effects of displacement of red-throated divers Possible behavioural, energetic and demographic effects of displacement of red-throated divers
This report comprises the main points of discussion and agreement during a workshop, held in Edinburgh in May 2017, to discuss how displacement might affect individuals and the Red-throated diver population; with additional information added by the scientists following the workshop.
Authors
Volker Dierschke, Robert W. Furness, Carrie E. Gray, Ib Krag Petersen, Joel A. Schmutz, Ramunas Zydelis, Francis Daunt
Vectors, hosts, and control measures for Zika virus in the Americas Vectors, hosts, and control measures for Zika virus in the Americas
We examine Zika virus (ZIKV) from an ecological perspective and with a focus on the Americas. We assess (1) the role of wildlife in ZIKV disease ecology, (2) how mosquito behavior and biology influence disease dynamics, and (3) how nontarget species and ecosystems may be impacted by vector control programs. Our review suggests that free-ranging, non-human primates may be involved in ZIKV
Authors
Sarah J. Thompson, John M. Pearce, Andrew M. Ramey
Forecasting consequences of changing sea ice availability for Pacific walruses Forecasting consequences of changing sea ice availability for Pacific walruses
The accelerating rate of anthropogenic alteration and disturbance of environments has increased the need for forecasting effects of environmental change on fish and wildlife populations. Models linking projections of environmental change with behavioral responses and bioenergetic effects can provide a basis for these forecasts. There is particular interest in forecasting effects of...
Authors
Mark S. Udevitz, Chadwick V. Jay, Rebecca L. Taylor, Anthony S. Fischbach, William S. Beatty, Shawn R. Noren
Genomics of Arctic cod Genomics of Arctic cod
The Arctic cod (Boreogadus saida) is an abundant marine fish that plays a vital role in the marine food web. To better understand the population genetic structure and the role of natural selection acting on the maternally-inherited mitochondrial genome (mitogenome), a molecule often associated with adaptations to temperature, we analyzed genetic data collected from 11 biparentally...
Authors
Robert E. Wilson, George K. Sage, Sarah A. Sonsthagen, Megan C. Gravley, Damian M. Menning, Sandra L. Talbot
Normalized difference vegetation index as an estimator for abundance and quality of avian herbivore forage in arctic Alaska Normalized difference vegetation index as an estimator for abundance and quality of avian herbivore forage in arctic Alaska
Tools that can monitor biomass and nutritional quality of forage plants are needed to understand how arctic herbivores may respond to the rapidly changing environment at high latitudes. The Normalized Difference Vegetation Index (NDVI) has been widely used to assess changes in abundance and distribution of terrestrial vegetative communities. However, the efficacy of NDVI to measure...
Authors
Kyle R. Hogrefe, Vijay P. Patil, Daniel R. Ruthrauff, Brandt W. Meixell, Michael E. Budde, Jerry W. Hupp, David H. Ward
Genetic implications of bottleneck effects of differing severities on genetic diversity in naturally recovering populations: An example from Hawaiian coot and Hawaiian gallinule Genetic implications of bottleneck effects of differing severities on genetic diversity in naturally recovering populations: An example from Hawaiian coot and Hawaiian gallinule
The evolutionary trajectory of populations through time is influenced by the interplay of forces (biological, evolutionary, and anthropogenic) acting on the standing genetic variation. We used microsatellite and mitochondrial loci to examine the influence of population declines, of varying severity, on genetic diversity within two Hawaiian endemic waterbirds, the Hawaiian coot and...
Authors
Sarah A. Sonsthagen, Robert E. Wilson, Jared G. Underwood
Attaching transmitters to waterbirds using one versus two subcutaneous anchors: Retention and survival trade-offs Attaching transmitters to waterbirds using one versus two subcutaneous anchors: Retention and survival trade-offs
A major challenge of wildlife telemetry is choosing an attachment technique that maximizes transmitter retention while minimizing negative side effects. For waterbirds, attachment of transmitters with subcutaneous anchors has been an effective and well-established technique, having been used on >40 species. This method was recently modified to include a second subcutaneous anchor...
Authors
Tyler Lewis, Daniel Esler, Brian D. Uher-Koch, Rian D. Dickson, Eric M. Anderson, Joseph R. Evenson, Jerry W. Hupp, Paul L. Flint
Polar bears, Ursus maritimus Polar bears, Ursus maritimus
Polar bears are the largest of the eight species of bears found worldwide and are covered in a pigment-free fur giving them the appearance of being white. They are the most carnivorous of bear species consuming a high-fat diet, primarily of ice-associated seals and other marine mammals. They range throughout the circumpolar Arctic to the southernmost extent of seasonal pack ice.
Authors
Karyn D. Rode, Ian Stirling
Monitoring the welfare of polar bear populations in a rapidly changing Arctic Monitoring the welfare of polar bear populations in a rapidly changing Arctic
Most programs for monitoring the welfare of wildlife populations support efforts aimed at reaching discrete management objectives, like mitigating conflict with humans. While such programs can be effective, their limited scope may preclude systemic evaluations needed for large-scale conservation initiatives, like the recovery of at-risk species. We discuss select categories of metrics...
Authors
Todd C. Atwood, Colleen G. Duncan, Kelly A. Patyk, Sarah A. Sonsthagen
Human-polar bear interactions in a changing Arctic: Existing and emerging concerns Human-polar bear interactions in a changing Arctic: Existing and emerging concerns
The behavior and sociality of polar bears (Ursus maritimus) have been shaped by evolved preferences for sea ice habitat and preying on marine mammals. However, human behavior is causing changes to the Arctic marine ecosystem through the influence of greenhouse gas emissions that drive long-term change in ecosystem processes and via the presence of in situ stressors associated with...
Authors
Todd C. Atwood, Kristin S. Simac, Stewart Breck, Geoff York, James Wilder