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
Bar-tailed Godwits Limosa lapponica in Alaska: Revisiting population estimates from the staging grounds
Bar-tailed Godwits Limosa lapponica baueri breed in Alaska and spend the nonbreeding season primarily in eastern Australia and New Zealand. Long-term declines spurred recent surveys at nonbreeding sites that yielded a revised population estimate of ~126,000 godwits. We conducted aerial surveys for Bar-tailed Godwits in 2018 and 2019 at pre-migratory staging sites in western Alaska. Counts from sim
Authors
Daniel R. Ruthrauff, Zak Pohlen, Heather M. Wilson, James Johnson
Bedrock gorge incision via anthropogenic meander cutoff
Bedrock river-gorge incision represents a fundamental landscape-shaping process, but a dearth of observational data at >10 yr timescales impedes understanding of gorge formation. I quantify 102 yr rates and processes of gorge incision using historical records, field observations, and topographic and image analysis of a human-caused bedrock meander cutoff along the North Fork Fortymile River in Ala
Authors
Adrian Bender
New insights into dietary management of polar bears (Ursus maritimus) and brown bears (U. arctos)
Although polar bears (Ursus maritimus) and brown bears (U. arctos) have been exhibited in zoological gardens for centuries, little is known about their nutritional needs. Multiple recent studies on both wild and captive polar bears and brown bears have found that they voluntarily select dietary macronutrient proportions resulting in much lower dietary protein and higher fat or digestible carbohydr
Authors
Charles T. Robbins, Troy N Tollefson, Karyn D. Rode, Joy Erlenbach, Amanda J. Ardente
South Africa's experimental fisheries closures and recovery of the endangered African penguin
In a scientifically-transformative project, South Africa implemented a decade-long field experiment to understand how fisheries may be affecting its most iconic seabird, the African penguin Spheniscus demersus. This unique effort prohibits the take of anchovy and sardine within relatively small areas around four African penguin breeding colonies, two in the Benguela upwelling ecosystem and two in
Authors
William J. Sydeman, George L. Hunt, E.K. Pikitch, Julia K. Parrish, John F. Piatt, P Dee Boersma, Les Kaufman, Daniel W. Anderson, Sarah Ann Thompson, Richard B. Sherley
Long-term variation in polar bear body condition and maternal investment relative to a changing environment
In the Arctic, warming air and ocean temperatures have resulted in substantial changes to sea ice, which is primary habitat for polar bears (Ursus maritimus). Reductions in extent, duration, and thickness have altered sea ice dynamics, which influences the ability of polar bears to reliably access marine mammal prey. Because nutritional condition is closely linked to population vital rates, a prog
Authors
Todd C. Atwood, Karyn D. Rode, David C. Douglas, Kristin S. Simac, Anthony Pagano, Jeffrey F. Bromaghin
Strong evidence for two disjunct populations of Black Scoters Melanitta americana in North America
Black Scoters Melanitta americana were marked with satellite transmitters on Atlantic and Pacific coasts of North America to examine continental-scale population delineation. Scoters marked on the different coasts did not overlap at any stage of the annual cycle, suggesting that birds in the two regions could be monitored and managed as separate populations: 1) an Atlantic population, which winter
Authors
Timothy D. Bowman, Scott G. Gilliland, Jason L Schamber, Paul L. Flint, Daniel Esler, W. Sean Boyd, Daniel H. Rosenberg, Jean-Pierre L. Savard, Matthew Perry, Jason E. Osenkowski
Seasonality of solute flux and water source chemistry in a coastal glacierized watershed undergoing rapid change: Wolverine Glacier watershed, Alaska
As glaciers around the world rapidly lose mass, the tight coupling between glaciers and downstream ecosystems is resulting in widespread impacts on global hydrologic and biogeochemical cycling. However, a range of challenges make it difficult to conduct research in glacierized systems and our knowledge of seasonally changing hydrologic processes and solute sources and signatures is limited. This i
Authors
Anna Bergstrom, Joshua C. Koch, Shad O'Neel, Emily Baker
The role of preexisting upper plate strike-slip faults during long-lived (ca. 30 Myr) oblique flat slab subduction, southern Alaska
Upper plates of subduction zones commonly respond to flat slab subduction by structural reactivation, magmatic arc disruption, and foreland basin inversion. However, the role of active strike-slip faults in focusing convergent deformation and magmatism in response to oblique flat slab subduction remains less clear. Here, we present new detrital apatite fission-track (dAFT) ages from 12 modern catc
Authors
Trevor Waldien, Richard O. Lease, Sarah Roeske, Jeff Benowitz, Paul O'Sullivan
Diagenetic barite-pyrite-wurtzite formation and redox signatures in Triassic mudstone, Brooks Range, northern Alaska
Mineralogical and geochemical studies of interbedded black and gray mudstones in the Triassic part of the Triassic-Jurassic Otuk Formation (northern Alaska) document locally abundant barite and pyrite plus diverse redox signatures. These strata, deposited in an outer shelf setting at paleolatitudes of ~45 to 60°N, show widespread sedimentological evidence for bioturbation. Barite occurs preferenti
Authors
John F. Slack, Ryan J. McAleer, Wayne (Pat) Shanks, Julie A. Dumoulin
Effects of sea ice decline and summer land use on polar bear home range size in the Beaufort Sea
Animals responding to habitat loss and fragmentation may increase their home ranges to offset declines in localized resources or they may decrease their home ranges and switch to alternative resources. In many regions of the Arctic, polar bears (Ursus maritimus) exhibit some of the largest home ranges of any quadrupedal mammal. Polar bears are presently experiencing a rapid decline in Arctic sea i
Authors
Anthony M. Pagano, George M. Durner, Todd C. Atwood, David C. Douglas
Antimicrobial resistance: Wildlife as indicators of anthropogenic environmental contamination across space and through time
Prior assessments support wildlife as indicators of anthropogenically influenced antimicrobial resistance across the landscape. A ground-breaking new study suggests that wildlife may also provide information on antimicrobial resistance in the environment through time.
Authors
Andrew M. Ramey
Evaluation of satellite imagery for monitoring Pacific walruses at a large coastal haulout
Pacific walruses (Odobenus rosmarus divergens) are using coastal haulouts in the Chukchi Sea more often and in larger numbers to rest between foraging bouts in late summer and autumn in recent years, because climate warming has reduced availability of sea ice that historically had provided resting platforms near their preferred benthic feeding grounds. With greater numbers of walruses hauling out
Authors
Anthony S. Fischbach, David C. Douglas