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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

Morphological and molecular characterization of Sarcocystis arctica-like sarcocysts from the Arctic fox (Vulpes lagopus) from Alaska, USA

The muscles of herbivores commonly harbor sarcocysts of parasites belonging to species in the genus Sarcocystis, but such muscle parasites are rare in carnivores. Here, we report Sarcocystis arctica-like sarcocysts in muscles of Arctic foxes (Vulpes lagopus) from Alaska, USA, for the first time. The tongues of 56 foxes were examined for Sarcocystis infection using several methods. Sarcocystis brad
Authors
Camila K. Cerqueira-Cézar, Peter C. Thompson, Shiv K. Verma, Joseph Mowery, Rafael Calero-Bernal, Fernando H. Antunes Murata, David R. Sinnett, Caroline R. Van Hemert, Benjamin M. Rosenthal, Jitender P. Dubey

Landsat-based trend analysis of lake dynamics across northern permafrost regions

Lakes are a ubiquitous landscape feature in northern permafrost regions. They have a strong impact on carbon, energy and water fluxes and can be quite responsive to climate change. The monitoring of lake change in northern high latitudes, at a sufficiently accurate spatial and temporal resolution, is crucial for understanding the underlying processes driving lake change. To date, lake change studi
Authors
Ingmar Nitze, Guido Grosse, Benjamin M. Jones, Christopher D. Arp, Mathias Ulrich, Alexander Federov, Alexandra Veremeeva

Younger-Dryas cooling and sea-ice feedbacks were prominent features of the Pleistocene-Holocene transition in Arctic Alaska

Declining sea-ice extent is currently amplifying climate warming in the Arctic. Instrumental records at high latitudes are too short-term to provide sufficient historical context for these trends, so paleoclimate archives are needed to better understand the functioning of the sea ice-albedo feedback. Here we use the oxygen isotope values of wood cellulose in living and sub-fossil willow shrubs (δ1
Authors
Benjamin V. Gaglioti, Daniel H. Mann, Matthew J. Wooller, Benjamin M. Jones, Gregory C. Wiles, Pamela Groves, Michael L. Kunz, Carson Baughman, Richard E. Reanier

A genetic signature of the evolution of loss of flight in the Galapagos cormorant

INTRODUCTIONChanges in the size and proportion of limbs and other structures have played a key role in the evolution of species. One common class of limb modification is recurrent wing reduction and loss of flight in birds. Indeed, Darwin used the occurrence of flightless birds as an argument in favor of his theory of natural selection. Loss of flight has evolved repeatedly and is found among 26 f
Authors
Alejandro Burga, Weiguang Wang, Eyal Ben-David, Paul C. Wolf, Andrew M. Ramey, Claudio Verdugo, Karen Lyons, Patricia G. Parker, Leonid Kruglyak

Migration trends of Sockeye Salmon at the northern edge of their distribution

Climate change is affecting arctic and subarctic ecosystems, and anadromous fish such as Pacific salmon Oncorhynchus spp. are particularly susceptible due to the physiological challenge of spawning migrations. Predicting how migratory timing will change under Arctic warming scenarios requires an understanding of how environmental factors drive salmon migrations. Multiple mechanisms exist by which
Authors
Michael P. Carey, Christian E. Zimmerman, Kevin D. Keith, Merlyn Schelske, Charles Lean, David C. Douglas

Duckling survival of mallards in Southland, New Zealand

The southern portion of New Zealand's South Island is a productive area for mallards (Anas platyrhynchos) despite a notable lack of permanent or semi-permanent wetlands. Most broods are reared in pastures that may or may not be flooded with ephemeral water. In recent years, there has been an increased conversion from continuous to sporadic grazing that has resulted in a functional change in the em
Authors
Erin Garrick, Courtney L. Amundson, Phillip J. Seddon

Seasonal and spatial variabilities in northern Gulf of Alaska surface water iron concentrations driven by shelf sediment resuspension, glacial meltwater, a Yakutat eddy, and dust

Phytoplankton growth in the Gulf of Alaska (GoA) is limited by iron (Fe), yet Fe sources are poorly constrained. We examine the temporal and spatial distributions of Fe, and its sources in the GoA, based on data from three cruises carried out in 2010 from the Copper River (AK) mouth to beyond the shelf break. April data are the first to describe late winter Fe behavior before surface water nitrate
Authors
John Crusius, Andrew W. Schroth, Joseph A. Resing, Jay Cullen, Robert W. Campbell

Uncertainties in forecasting the response of polar bears to global climate change

Several sources of uncertainty affect how precisely the future status of polar bears (Ursus maritimus) can be forecasted. Foremost are unknowns about the future levels of global greenhouse gas emissions, which could range from an unabated increase to an aggressively mitigated reduction. Uncertainties also arise because different climate models project different amounts and rates of future warming
Authors
David C. Douglas, Todd C. Atwood

Seasonal movements of the Short-eared Owl (Asio flammeus) in western North America as revealed by satellite telemetry

The Short-eared Owl (Asio flammeus) is a widespread raptor whose abundance and distribution fluctuates in response to the varying amplitudes of its prey, which are predominately microtines. Previous efforts to describe the seasonal movements of Short-eared Owls have been hindered by few band recoveries and the species' cryptic and irruptive behavior. We attached satellite transmitters to adult Sho
Authors
James A. Johnson, Travis L. Booms, Lucas H. DeCicco, David C. Douglas

Ecological change drives a decline in mercury concentrations in southern Beaufort Sea polar bears

We evaluated total mercury (THg) concentrations and trends in polar bears from the southern Beaufort Sea subpopulation from 2004 to 2011. Hair THg concentrations ranged widely among individuals from 0.6 to 13.3 μg g–1 dry weight (mean: 3.5 ± 0.2 μg g–1). Concentrations differed among sex and age classes: solitary adult females ≈ adult females with cubs ≈ subadults > adult males ≈ yearlings > cubs-
Authors
Melissa A. McKinney, Todd C. Atwood, Sara Pedro, Elizabeth L. Peacock

Sculpted by water, elevated by earthquakes—The coastal landscape of Glacier Bay National Park, Alaska

Within Glacier Bay National Park in southeastern Alaska, the Fairweather Fault represents the onshore boundary between two of Earth’s constantly moving tectonic plates: the North American Plate and the Yakutat microplate. Satellite measurements indicate that during the past few decades the Yakutat microplate has moved northwest at a rate of nearly 5 centimeters per year relative to the North Ameri
Authors
Robert C. Witter, Adam LeWinter, Adrian M. Bender, Craig Glennie, David C. Finnegan

Performance and retention of lightweight satellite radio tags applied to the ears of polar bears (Ursus maritimus)

BackgroundSatellite telemetry studies provide information that is critical to the conservation and management of species affected by ecological change. Here we report on the performance and retention of two types (SPOT-227 and SPOT-305A) of ear-mounted Argos-linked satellite transmitters (i.e., platform transmitter terminal, or PTT) deployed on free-ranging polar bears in Eastern Greenland, Baffin
Authors
Øystein Wiig, Erik W. Born, Kristin L. Laidre, Rune Dietz, Mikkel Villum Jensen, George M. Durner, Anthony M. Pagano, Eric V. Regehr, Michelle St. Martin, Stephen N. Atkinson, Markus Dyck