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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: 3087

QFASAR: Quantitative fatty acid signature analysis with R QFASAR: Quantitative fatty acid signature analysis with R

Knowledge of predator diets provides essential insights into their ecology, yet diet estimation is challenging and remains an active area of research.Quantitative fatty acid signature analysis (QFASA) is a popular method of estimating diet composition that continues to be investigated and extended. However, software to implement QFASA has only recently become publicly available.I...
Authors
Jeffrey F. Bromaghin

Comparison of acoustic recorders and field observers for monitoring tundra bird communities Comparison of acoustic recorders and field observers for monitoring tundra bird communities

Acoustic recorders can be useful for studying bird populations but their efficiency and accuracy should be assessed in pertinent ecological settings before use. We investigated the utility of an acoustic recorder for monitoring abundance of tundra‐breeding birds relative to point‐count surveys in northwestern Alaska, USA, during 2014. Our objectives were to 1) compare numbers of birds...
Authors
Skyler T. Vold, Colleen M. Handel, Lance B. McNew

A comment on “temporal variation in survival and recovery rates of lesser scaup” A comment on “temporal variation in survival and recovery rates of lesser scaup”

Concerns about declines in the abundance of lesser scaup (Aythya affinis) have promoted a number of analyses to understand reasons for this decline. Unfortunately, most of these analyses, including that of Arnold et al. (2016 Journal of Wildlife Management 80: 850–861), are based on observational studies leading to weak inference. Although we commend the efforts of Arnold et al. (2016...
Authors
Mark S. Lindberg, G. Scott Boomer, Joel A. Schmutz, Johann A. Walker

Simultaneous estimation of diet composition and calibration coefficients with fatty acid signature data Simultaneous estimation of diet composition and calibration coefficients with fatty acid signature data

Knowledge of animal diets provides essential insights into their life history and ecology, although diet estimation is challenging and remains an active area of research. Quantitative fatty acid signature analysis (QFASA) has become a popular method of estimating diet composition, especially for marine species. A primary assumption of QFASA is that constants called calibration...
Authors
Jeffrey F. Bromaghin, Suzanne M. Budge, Gregory W. Thiemann, Karyn D. Rode

Polar bears and sea ice habitat change Polar bears and sea ice habitat change

The polar bear (Ursus maritimus) is an obligate apex predator of Arctic sea ice and as such can be affected by climate warming-induced changes in the extent and composition of pack ice and its impacts on their seal prey. Sea ice declines have negatively impacted some polar bear subpopulations through reduced energy input because of loss of hunting habitats, higher energy costs due to...
Authors
George M. Durner, Todd C. Atwood

Polar bears experience skeletal muscle atrophy in response to food deprivation and reduced activity in winter and summer Polar bears experience skeletal muscle atrophy in response to food deprivation and reduced activity in winter and summer

When reducing activity and using stored energy during seasonal food shortages, animals risk degradation of skeletal muscles, although some species avoid or minimize the resulting atrophy while experiencing these conditions during hibernation. Polar bears may be food deprived and relatively inactive during winter (when pregnant females hibernate and hunting success declines for other...
Authors
John P. Whiteman, Henry J. Harlow, George M. Durner, Eric V. Regehr, Bryan C. Rourke, Manuel Robles, Steven C. Amstrup, Merav Ben-David

Maintenance of influenza A viruses and antibody response in mallards (Anas platyrhynchos) sampled during the non-breeding season in Alaska Maintenance of influenza A viruses and antibody response in mallards (Anas platyrhynchos) sampled during the non-breeding season in Alaska

Prevalence of influenza A virus (IAV) infections in northern-breeding waterfowl has previously been reported to reach an annual peak during late summer or autumn; however, little is known about IAV infection dynamics in waterfowl populations persisting at high-latitude regions such as Alaska, during winter. We captured mallards (Anas platyrhynchos) throughout the non-breeding season...
Authors
Timothy J. Spivey, Mark S. Lindberg, Brandt W. Meixell, Kyle R. Smith, Wendy Blay Puryear, Kimberly R. Davis, Jonathan A. Runstadler, David E. Stallknecht, Andrew M. Ramey

Small mammals as indicators of climate, biodiversity, and ecosystem change Small mammals as indicators of climate, biodiversity, and ecosystem change

Climate is a driving evolutionary force for biodiversity in high-latitude Alaska. This region is complex and dynamic with high annual variation in temperature and light. Through deeper time, Alaska has experienced major climate extremes over much longer periodicity. For example, the Quaternary Period (the last ~2.5 million years), commonly known as the Ice Age, was punctuated by more...
Authors
Andrew G. Hope, Eric Waltari, Nathan R. Morse, M.J. Flamme, Sandra L. Talbot, Joseph A. Cook

Combined analysis of roadside and off-road breeding bird survey data to assess population change in Alaska Combined analysis of roadside and off-road breeding bird survey data to assess population change in Alaska

Management interest in North American birds has increasingly focused on species that breed in Alaska, USA, and Canada, where habitats are changing rapidly in response to climatic and anthropogenic factors. We used a series of hierarchical models to estimate rates of population change in 2 forested Bird Conservation Regions (BCRs) in Alaska based on data from the roadside North American...
Authors
Colleen M. Handel, John R. Sauer

New constraints on coseismic slip during southern Cascadia subduction zone earthquakes over the past 4600 years implied by tsunami deposits and marine turbidites New constraints on coseismic slip during southern Cascadia subduction zone earthquakes over the past 4600 years implied by tsunami deposits and marine turbidites

Forecasting earthquake and tsunami hazards along the southern Cascadia subduction zone is complicated by uncertainties in the amount of megathrust fault slip during past ruptures. Here, we estimate slip on hypothetical ruptures of the southern part of the megathrust through comparisons of late Holocene Cascadia earthquake histories derived from tsunami deposits on land and marine...
Authors
George R. Priest, Robert C. Witter, Yinglong J. Zhang, Chris Goldfinger, Kelin Wang, Jonathan C. Allan

Detect and exploit hidden structure in fatty acid signature data Detect and exploit hidden structure in fatty acid signature data

Estimates of predator diet composition are essential to our understanding of their ecology. Although several methods of estimating diet are practiced, methods based on biomarkers have become increasingly common. Quantitative fatty acid signature analysis (QFASA) is a popular method that continues to be refined and extended. Quantitative fatty acid signature analysis is based on...
Authors
Jeffrey F. Bromaghin, Suzanne M. Budge, Gregory W. Thiemann

Hydrologic impacts of changes in climate and glacier extent in the Gulf of Alaska watershed Hydrologic impacts of changes in climate and glacier extent in the Gulf of Alaska watershed

High‐resolution regional‐scale hydrologic models were used to quantify the response of late 21st century runoff from the Gulf of Alaska (GOA) watershed to changes in regional climate and glacier extent. NCEP Climate Forecast System Reanalysis data were combined with five Coupled Model Intercomparison Project Phase 5 general circulation models (GCMs) for two representative concentration...
Authors
Jordan Beamer, Dave Hill, Daniel Mcgrath, Anthony A. Arendt, Christian Kienholz
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