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: 3087
Ovarian follicle dynamics of female Greater Scaup during egg production Ovarian follicle dynamics of female Greater Scaup during egg production
Studies of female waterfowl nutrient reserve use during egg production require a precise understanding of ovarian follicle dynamics to correctly interpret breeding status, and, therefore, derive proper inference. Concerns over numerical declines of North American scaup have increased the need to better understand the role of female condition in reproductive performance. We quantified...
Authors
Kristen B. Gorman, Paul L. Flint, Daniel Esler, T.D. Williams
Holocene slip rate for the western segment of the Castle Mountain fault, Alaska Holocene slip rate for the western segment of the Castle Mountain fault, Alaska
The western segment of the Castle Mountain fault poses a significant seismic hazard to the most populated region of south-central Alaska. We identify a previously unrecognized margin of a postglacial outwash channel that is offset right laterally 36 ± 4 m across the western segment of the Castle Mountain fault. This offset occurred after glaciers withdrew from the lowland 11,300–15,380...
Authors
J.B. Willis, Peter J. Haeussler, R.L. Bruhn, G.C. Willis
Stress hormones link food availability and population processes in seabirds Stress hormones link food availability and population processes in seabirds
Catastrophic population declines in marine top predators in the northern Pacific have been hypothesized to result from nutritional stress affecting reproduction and survival of individuals. However, empirical evidence for food-related stress in wild animals is frequently lacking or inconclusive. We used a field endocrinology approach to measure stress, identify its causes, and examine a...
Authors
A.S. Kitaysky, John F. Piatt, J.C. Wingfield
Variation in winter diet of southern Beaufort Sea polar bears inferred from stable isotope analysis Variation in winter diet of southern Beaufort Sea polar bears inferred from stable isotope analysis
Ringed seals (Phoca hispida Schreber, 1775 = Pusa hispida (Schreber, 1775)) and bearded seals (Erignathus barbatus (Erxleben, 1777)) represent the majority of the polar bear (Ursus maritimus Phipps, 1774) annual diet. However, remains of lower trophic level bowhead whales (Balaena mysticetus L., 1758) are available in the southern Beaufort Sea and their dietary contribution to polar...
Authors
T.W. Bentzen, Erich H. Follmann, Steven C. Amstrup, G.S. York, M. J. Wooller, T. M. O'Hara
Detrital zircon geochronology of some neoproterozoic to triassic rocks in interior Alaska Detrital zircon geochronology of some neoproterozoic to triassic rocks in interior Alaska
No abstract available.
Authors
D. C. Bradley, W.C. McClelland, J. L. Wooden, A.B. Till, S. M. Roeske, Marti L. Miller, Susan M. Karl, J.G. Abbott
Strategies for survival: Marine mammals Strategies for survival: Marine mammals
No abstract available.
Authors
Sara J. Iverson, Alan M. Springer, James L. Bodkin
Food availability affects the maternal transfer of androgens and antibodies into eggs of a colonial seabird Food availability affects the maternal transfer of androgens and antibodies into eggs of a colonial seabird
Mothers can improve the quality of their offspring by increasing the level of certain components in their eggs. To examine whether or not mothers increase deposition of such components in eggs as a function of food availability, we food‐supplemented black‐legged kittiwake females (Rissa tridactyla) before and during egg laying and compared deposition of androgens and antibodies into eggs...
Authors
J. Gasparini, T. Boulinier, V.A. Gill, D. Gil, Scott A. Hatch, A. Roulin
Weirs: Counting and sampling adult salmonids in streams and rivers Weirs: Counting and sampling adult salmonids in streams and rivers
Weirs—which function as porous barriers built across stream—have long been used to capture migrating fish in flowing waters. For example, the Netsilik peoples of northern Canada used V-shaped weirs constructed of river rocks gathered onsite to capture migrating Arctic char Salvelinus alpinus (Balikci 1970). Similarly, fences constructed of stakes and a latticework of willow branches or...
Authors
Christian E. Zimmerman, Laura M. Zabkar
The blind men and the elephant: Concerns about the use of juvenile proportion data The blind men and the elephant: Concerns about the use of juvenile proportion data
Juvenile proportion data in shorebirds are being used with increasing frequency to estimate recruitment and even breeding success. Although this area of investigation holds great promise, flaws in current study designs preclude great confidence in the broad-scale inferences being drawn. We present data from our own investigations on juvenile proportions in Bar-tailed Godwits Limosa...
Authors
Brian J. McCaffery, Colleen M. Handel, Robert E. Gill, Daniel R. Ruthrauff
Population ecology of seabirds in Cook Inlet: Chapter 8 Population ecology of seabirds in Cook Inlet: Chapter 8
[No abstract available]
Authors
John F. Piatt, Ann Harding
Polycyclic aromatic hydrocarbon exposure in Steller's eiders (Polysticta stelleri) and harlequin ducks (Histronicus histronicus) in the Eastern Aleutian Islands, Alaska, USA Polycyclic aromatic hydrocarbon exposure in Steller's eiders (Polysticta stelleri) and harlequin ducks (Histronicus histronicus) in the Eastern Aleutian Islands, Alaska, USA
Seaducks may be affected by harmful levels of polycyclic aromatic hydrocarbons (PAHs) at seaports near the Arctic. As an indicator of exposure to PAHs, we measured hepatic enzyme 7-ethoxyresorufin-O-deethylase activity (EROD) to determine cytochrome P4501A induction in Steller's eiders (Polysticta stelleri) and Harlequin ducks (Histronicus histronicus) from Unalaska, Popof, and Unga...
Authors
A.K. Miles, Paul L. Flint, K.A. Trust, M.A. Ricca, S.E. Spring, D.E. Arrieta, T. Hollmen, B.W. Wilson
Methods to assess natural and anthropogenic thaw lake drainage on the western Arctic coastal plain of northern Alaska Methods to assess natural and anthropogenic thaw lake drainage on the western Arctic coastal plain of northern Alaska
Thousands of lakes are found on the Arctic Coastal Plain of northern Alaska and northwestern Canada. Developed atop continuous permafrost, these thaw lakes and associated drained thaw lake basins are the dominant landscape elements and together cover 46% of the 34,570 km2western Arctic Coastal Plain (WACP). Lakes drain by a variety of episodic processes, including coastal erosion, stream
Authors
Kenneth M. Hinkel, Benjamin M. Jones, Wendy R. Eisner, Chris J. Cuomo, R.A. Beck, R. Frohn