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
Accounting for rate variation among lineages in comparative demographic analyses
Genetic analyses of contemporary populations can be used to estimate the demographic histories of species within an ecological community. Comparison of these demographic histories can shed light on community responses to past climatic events. However, species experience different rates of molecular evolution, and this presents a major obstacle to comparative demographic analyses. We address this p
Authors
Andrew G. Hope, Simon Y. W. Ho, Jason L. Malaney, Joseph A. Cook, Sandra L. Talbot
Survival of surf scoters and white-winged scoters during remigial molt
Quantifying sources and timing of variation in demographic rates is necessary to determine where and when constraints may exist within the annual cycle of organisms. Surf scoters (Melanitta perspicillata) and white-winged scoters (M. fusca) undergo simultaneous remigial molt during which they are flightless for >1 month. Molt could result in reduced survival due to increased predation risk or incr
Authors
Brian D. Uher-Koch, Daniel Esler, Rian D. Dickson, Jerry W. Hupp, Joseph R. Evenson, Eric M. Anderson, Jennifer Barrett, Joel A. Schmutz
Guidelines for the collection of continuous stream water-temperature data in Alaska
Objectives of stream monitoring programs differ considerably among many of the academic, Federal, state, tribal, and non-profit organizations in the state of Alaska. Broad inclusion of stream-temperature monitoring can provide an opportunity for collaboration in the development of a statewide stream-temperature database. Statewide and regional coordination could reduce overall monitoring cost, whi
Authors
Ryan C. Toohey, Edward G. Neal, Gary L. Solin
Environmental and physiological influences to isotopic ratios of N and protein status in a montane ungulate in winter
Winter severity can influence large herbivore populations through a reduction in maternal proteins available for reproduction. Nitrogen (N) isotopes in blood fractions can be used to track the use of body proteins in northern and montane ungulates. We studied 113 adult female caribou for 13 years throughout a series of severe winters that reduced population size and offspring mass. After these sev
Authors
David D. Gustine, Perry S. Barboza, Layne G. Adams, Nathan B. Wolf
Multilocus phylogeography and systematic revision of North American water shrews (genus: Sorex)
North American water shrews, which have traditionally included Sorex alaskanus, S. bendirii, and S. palustris, are widely distributed through Nearctic boreal forests and adapted for life in semiaquatic environments. Molecular mitochondrial signatures for these species have recorded an evolutionary history with variable levels of regional divergence, suggesting a strong role of Quaternary environme
Authors
Andrew G. Hope, Nicholas Panter, Joseph A. Cook, Sandra L. Talbot, David W. Nagorsen
The Early Jurassic Bokan Mountain peralkaline granitic complex (southeastern Alaska): geochemistry, petrogenesis and rare-metal mineralization
The Early Jurassic (ca. 177 Ma) Bokan Mountain granitic complex, located on southern Prince of Wales Island, southernmost Alaska, cross-cuts Paleozoic igneous and metasedimentary rocks of the Alexander terrane of the North American Cordillera and was emplaced during a rifting event. The complex is a circular body (~3 km in diameter) of peralkaline granitic composition that has a core of arfvedsoni
Authors
Jaroslav Dostal, Daniel J. Kontak, Susan M. Karl
A hierarchical model combining distance sampling and time removal to estimate detection probability during avian point counts
Imperfect detection during animal surveys biases estimates of abundance and can lead to improper conclusions regarding distribution and population trends. Farnsworth et al. (2005) developed a combined distance-sampling and time-removal model for point-transect surveys that addresses both availability (the probability that an animal is available for detection; e.g., that a bird sings) and perceptib
Authors
Courtney L. Amundson, J. Andrew Royle, Colleen M. Handel
Reconstruction of an early Paleozoic continental margin based on the nature of protoliths in the Nome Complex, Seward Peninsula, Alaska
The Nome Complex is a large metamorphic unit that sits along the southern boundary of the Arctic Alaska–Chukotka terrane, the largest of several micro continental fragments of uncertain origin located between the Siberian and Laurentian cratons. The Arctic Alaska–Chukotka terrane moved into its present position during the Mesozoic; its Mesozoic and older movements are central to reconstruction of
Authors
Alison B. Till, Julie A. Dumoulin, Robert A. Ayuso, John N. Aleinikoff, Jeffrey M. Amato, John F. Slack, W.C. Pat Shanks
Historical and contemporary imagery to assess ecosystem change on the Arctic coastal plain of northern Alaska
The Arctic Coastal Plain of northern Alaska is a complex landscape of lakes, streams, and wetlands scattered across low-relief tundra that is underlain by permafrost. This region of the Arctic has experienced a warming trend over the past three decades leading to thawing of on-shore permafrost and the disappearance of sea ice at unprecedented rates. The U.S. Geological Survey’s (USGS) Changing Arc
Authors
Ken D. Tape, John M. Pearce, Dennis H. Walworth, Brandt W. Meixell, Tom F. Fondell, David D. Gustine, Paul L. Flint, Jerry W. Hupp, Joel A. Schmutz, David H. Ward
Cenozoic mountain building on the northeastern Tibetan Plateau
Northeastern Tibetan Plateau growth illuminates the kinematics, geodynamics, and climatic consequences of large-scale orogenesis, yet only recently have data become available to outline the spatiotemporal pattern and rates of this growth. I review the tectonic history of range growth across the plateau margin north of the Kunlun fault (35°–40°N) and east of the Qaidam basin (98°–107°E), synthesizi
Authors
Richard O. Lease
Polar bears from space: Assessing satellite imagery as a tool to track Arctic wildlife
Development of efficient techniques for monitoring wildlife is a priority in the Arctic, where the impacts of climate change are acute and remoteness and logistical constraints hinder access. We evaluated high resolution satellite imagery as a tool to track the distribution and abundance of polar bears. We examined satellite images of a small island in Foxe Basin, Canada, occupied by a high densit
Authors
Seth P. Stapleton, Michelle A. LaRue, Nicolas Lecomte, Stephen N. Atkinson, David L. Garshelis, Claire Porter, Todd C. Atwood
Climate-driven effects of fire on winter habitat for caribou in the Alaskan-Yukon Arctic
Climatic warming has direct implications for fire-dominated disturbance patterns in northern ecosystems. A transforming wildfire regime is altering plant composition and successional patterns, thus affecting the distribution and potentially the abundance of large herbivores. Caribou (Rangifer tarandus) are an important subsistence resource for communities throughout the north and a species that de
Authors
David D. Gustine, Todd J. Brinkman, Michael A. Lindgren, Jennifer I. Schmidt, T. Scott Rupp, Layne G. Adams