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
Potential population-level effects of increased haulout-related mortality of Pacific walrus calves
Availability of summer sea ice has been decreasing in the Chukchi Sea during recent decades, and increasing numbers of Pacific walruses have begun using coastal haulouts in late summer during years when sea ice retreats beyond the continental shelf. Calves and yearlings are particularly susceptible to being crushed during disturbance events that cause the herd to panic and stampede at these large
Authors
Mark S. Udevitz, Rebecca L. Taylor, Joel L. Garlich-Miller, Lori T. Quakenbush, Jonathan A. Snyder
Patterns of social association in the franciscana, Pontoporia blainvillei
Little is known from living animals about the social patterns of the franciscana, Pontoporia blainvillei, a small dolphin inhabiting a narrow strip of coastal waters off Argentina, Uruguay, and Brazil. These dolphins tend to be found in small groups, typically composed of two or three individuals (Bordino et al. 1999). Throughout much of the species' range, franciscanas encounter artisanal gill ne
Authors
Randall S. Wells, Pablo Bordino, David C. Douglas
Movements and dive patterns of short-finned pilot whales (Globicephala macrorhynchus) released from a mass stranding in the Florida Keys
Short-finned pilot whales (Globicephala macrorhynchus) are among the most common cetaceans to engage in mass strandings in the southeastern United States. Because these are primarily pelagic, continental shelf-edge animals, much of what is known about this species has derived from mass stranding events. Post-release monitoring via satellite-linked telemetry was conducted with two adult males deter
Authors
Randall S. Wells, Erin M. Fougeres, Arthur G. Cooper, Robert O. Stevens, Micah Brodsky, Robert Lingenfelser, Chris Dold, David C. Douglas
Plausible combinations: An improved method to evaluate the covariate structure of Cormack-Jolly-Seber mark-recapture models
Mark-recapture models are extensively used in quantitative population ecology, providing estimates of population vital rates, such as survival, that are difficult to obtain using other methods. Vital rates are commonly modeled as functions of explanatory covariates, adding considerable flexibility to mark-recapture models, but also increasing the subjectivity and complexity of the modeling process
Authors
Jeffrey F. Bromaghin, Trent L. McDonald, Steven C. Amstrup
Rapid runoff via shallow throughflow and deeper preferential flow in a boreal catchment underlain by frozen silt (Alaska, USA)
In high-latitude catchments where permafrost is present, runoff dynamics are complicated by seasonal active-layer thaw, which may cause a change in the dominant flowpaths as water increasingly contacts mineral soils of low hydraulic conductivity. A 2-year study, conducted in an upland catchment in Alaska (USA) underlain by frozen, well-sorted eolian silt, examined changes in infiltration and runof
Authors
Joshua C. Koch, Stephanie A. Ewing, Robert G. Striegl, Diane M. McKnight
Water-quality and flow data, Chulitna River basin, Southwest Alaska, October 2009-June 2012
The Chulitna River basin in southwest Alaska drains an area of about 1,160 square miles, with the lower 158 square miles of the basin in Lake Clark National Park and Preserve. Water from this basin influences Lake Clark ecosystems that support salmon that, in part, sustain the Bristol Bay fishery. An area of about 391 square miles in the upper part of the Chulitna River basin has been staked for m
Authors
Timothy P. Brabets
Testing the use of microfossils to reconstruct great earthquakes at Cascadia
Coastal stratigraphy from the Pacific Northwest of the United States contains evidence of sudden subsidence during ruptures of the Cascadia subduction zone. Transfer functions (empirical relationships between assemblages and elevation) can convert microfossil data into coastal subsidence estimates. Coseismic deformation models use the subsidence values to constrain earthquake magnitudes. To test t
Authors
S. E. Engelhart, B. P Horton, Alan R. Nelson, A. D. Hawkes, Robert C. Witter, K. Wang, P.-L. Wang, C. H. Vane
Quantifying landscape change in an arctic coastal lowland using repeat airborne LiDAR
Increases in air, permafrost, and sea surface temperature, loss of sea ice, the potential for increased wave energy, and higher river discharge may all be interacting to escalate erosion of arctic coastal lowland landscapes. Here we use airborne light detection and ranging (LiDAR) data acquired in 2006 and 2010 to detect landscape change in a 100 km2 study area on the Beaufort Sea coastal plain of
Authors
Benjamin M. Jones, Jason M. Stoker, Ann E. Gibbs, Guido Grosse, Vladimir E. Romanovsky, Thomas A. Douglas, Nichole E.M. Kinsman, Bruce M. Richmond
Residency times and patterns of movement of postbreeding dunlin on a subarctic staging area in Alaska
Understanding how individuals use key resources is critical for effective conservation of a population. The Yukon-Kuskokwim Delta (YKD) in western Alaska is the most important postbreeding staging area for shorebirds in the subarctic North Pacific, yet little is known about movements of shorebirds there during the postbreeding period. To address this information gap, we studied residency times and
Authors
Nils Warnock, Colleen M. Handel, Robert E. Gill, Brian J. McCaffery
Genetic relationships among some subspecies of the Peregrine Falcon (Falco peregrinus L.), inferred from mitochondrial DNA control-region sequences
The ability to successfully colonize and persist in diverse environments likely requires broad morphological and behavioral plasticity and adaptability, and this may partly explain why the Peregrine Falcon (Falco peregrinus) exhibits a large range of morphological characteristics across their global distribution. Regional and local differences within Peregrine Falcons were sufficiently variable th
Authors
Clayton M. White, Sarah A. Sonsthagen, George K. Sage, Clifford Anderson, Sandra L. Talbot
The environmental-data automated track annotation (Env-DATA) system: linking animal tracks with environmental data
The movement of animals is strongly influenced by external factors in their surrounding environment such as weather, habitat types, and human land use. With advances in positioning and sensor technologies, it is now possible to capture animal locations at high spatial and temporal granularities. Likewise, scientists have an increasing access to large volumes of environmental data. Environmental da
Authors
Somayeh Dodge, Gil Bohrer, Rolf P. Weinzierl, Sarah C. Davidson, Roland Kays, David C. Douglas, Sebastian Cruz, J. Han, David Brandes, Martin Wikelski
Executive summary: Climate change in the northwest: Implications for our landscapes, waters, and communities
Climate Change in the Northwest: Implications for Our Landscapes, Waters, and Communities is aimed at assessing the state of knowledge about key climate impacts and consequences to various sectors and communities in the northwest United States. It draws on a wealth of peer-reviewed literature, earlier state-level assessment reports conducted for Washington (2009) and Oregon (2010), as well as a ri
Authors
Meghan M. Dalton, Jeffrey Bethel, Susan M. Capalbo, J.E. Cuhaciyan, Sanford D. Eigenbrode, Patty Glick, Laurie L. Houston, Jeremy S. Littell, Kathy Lynn, Philip W. Mote, Rick R. Raymondi, W. Spencer Reeder, Sarah L. Shafer, Amy K. Snover