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
Age-specific survival of tundra swans on the lower Alaska Peninsula
The population of Tundra Swans (Cygnus columbianus columbianus) breeding on the lower Alaska Peninsula represents the southern extremity of the species' range and is uniquely nonmigratory. We used data on recaptures, resightings, and recoveries of neck-collared Tundra Swans on the lower Alaska Peninsula to estimate collar loss, annual apparent survival, and other demographic parameters for the yea
Authors
Brandt W. Meixell, Mark S. Lindberg, Paul B. Conn, Christian P. Dau, John E. Sarvis, Kristine M. Sowl
Variation in body mass dynamics among sites in Black Brant Branta bernicla nigricans supports adaptivity of mass loss during moult
Birds employ varying strategies to accommodate the energetic demands of moult, one important example being changes in body mass. To understand better their physiological and ecological significance, we tested three hypotheses concerning body mass dynamics during moult. We studied Black Brant in 2006 and 2007 moulting at three sites in Alaska which varied in food availability, breeding status and w
Authors
Thomas F. Fondell, Paul L. Flint, Joel A. Schmutz, Jason L. Schamber, Christopher A. Nicolai
Identical metabolic rate and thermal conductance in Rock Sandpiper (Calidris ptilocnemis) subspecies with contrasting nonbreeding life histories
Closely related species or subspecies can exhibit metabolic differences that reflect site-specific environmental conditions. Whether such differences represent fixed traits or flexible adjustments to local conditions, however, is difficult to predict across taxa. The nominate race of Rock Sandpiper (Calidris ptilocnemis) exhibits the most northerly nonbreeding distribution of any shorebird in the
Authors
Daniel R. Ruthrauff, Anne Dekinga, Robert E. Gill, Theunis Piersma
Hydrologic controls on the transport and cycling of carbon and nitrogen in a boreal catchment underlain by continuous permafrost
Boreal ecosystems represent a large carbon (C) reservoir and a substantial source of greenhouse gases. Hydrologic conditions dictate whether C leached from boreal soils is processed in catchments or flushed to less productive environments via the stream. This study quantified hydrologic and biogeochemical C loss from a boreal catchment underlain by frozen silt, where flowpaths may deepen as the ac
Authors
Joshua C. Koch, Robert L. Runkel, Robert G. Striegl, Diane M. McKnight
Legal, ethical, and procedural bases for the use of aseptic techniques to implant electronic devices
The popularity of implanting electronic devices such as transmitters and data loggers into captive and free-ranging animals has increased greatly in the past two decades. The devices have become smaller, more reliable, and more capable (Printz 2004; Wilson and Gifford 2005; Metcalfe et al. 2012). Compared with externally mounted devices, implanted devices are largely invisible to external viewers
Authors
Daniel M. Mulcahy
Bokan Mountain peralkaline granitic complex, Alexander terrane (southeastern Alaska): evidence for Early Jurassic rifting prior to accretion with North America
The circular Bokan Mountain complex (BMC) on southern Prince of Wales Island, southernmost Alaska, is a Jurassic peralkaline granitic intrusion about 3 km in diameter that crosscuts igneous and metasedimentary rocks of the Alexander terrane. The BMC hosts significant rare metal (rare earth elements, Y, U, Th, Zr, and Nb) mineralization related to the last stage of BMC emplacement. U–Pb (zircon) an
Authors
Jaroslav Dostal, Susan M. Karl, J. Duncan Keppie, Daniel J. Kontak, J. Gregory Shellnutt
Fat or lean: adjustment of endogenous energy stores to predictable and unpredictable changes in allostatic load
1. The ability to store energy endogenously is an important ecological mechanism that allows animals to buffer predictable and unpredictable variation in allostatic load. The secretion of glucocorticoids, which reflects changes in allostatic load, is suggested to play a major role in the adjustment of endogenous stores to these varying conditions.
2. Although crucially important, the relationship
Authors
Jannik Schultner, Alexander S. Kitaysky, Jorg Welcker, Scott Hatch
Ecosystem services from converted land: the importance of tree cover in Amazonian pastures
Deforestation is responsible for a substantial fraction of global carbon emissions and changes in surface energy budgets that affect climate. Deforestation losses include wildlife and human habitat, and myriad forest products on which rural and urban societies depend for food, fiber, fuel, fresh water, medicine, and recreation. Ecosystem services gained in the transition from forests to pasture an
Authors
Kirsten Barrett, Judson Valentim, B. L. Turner
Wildlife disease and environmental health in Alaska
Environmental health is defined by connections between the physical environment, ecological health, and human health. Current research within the U.S. Geological Survey (USGS) recognizes the importance of this integrated research philosophy, which includes study of disease and pollutants as they pertain to wildlife and humans. Due to its key geographic location and significant wildlife resources,
Authors
Caroline R. Van Hemert, John M. Pearce, Karen Oakley, Mary E. Whalen
Effects of food availability on yolk androgen deposition in the black-legged kittiwake (Rissa tridactyla), a seabird with facultative brood reduction
In birds with facultative brood reduction, survival of the junior chick is thought to be regulated primarily by food availability. In black-legged kittiwakes (Rissa tridactyla) where parents and chicks are provided with unlimited access to supplemental food during the breeding season, brood reduction still occurs and varies interannually. Survival of the junior chick is therefore affected by facto
Authors
Z.M. Benowitz-Fredericks, Alexander S. Kitaysky, Jorg Welcker, Scott A. Hatch
Mercury and water-quality data from Rink Creek, Salmon River, and Good River, Glacier Bay National Park and Preserve, Alaska, November 2009-October 2011
Glacier Bay National Park and Preserve (GBNPP), Alaska, like many pristine high latitude areas, is exposed to atmospherically deposited contaminants such as mercury (Hg). Although the harmful effects of Hg are well established, information on this contaminant in southeast Alaska is scarce. Here, we assess the level of this contaminant in several aquatic components (water, sediments, and biological
Authors
Sonia A. Nagorski, Edward G. Neal, Timothy P. Brabets
Modern foraminifera, δ13C, and bulk geochemistry of central Oregon tidal marshes and their application in paleoseismology
We assessed the utility of δ13C and bulk geochemistry (total organic content and C:N) to reconstruct relative sea-level changes on the Cascadia subduction zone through comparison with an established sea-level indicator (benthic foraminifera). Four modern transects collected from three tidal environments at Siletz Bay, Oregon, USA, produced three elevation-dependent groups in both the foraminiferal
Authors
Simon E. Engelhart, Benajamin P. Horton, Christopher H. Vane, Alan R. Nelson, Robert C. Witter, Sarah R. Brody, Andrea D. Hawkes