Publications
Publications from the Alaska Science Center.
Filter Total Items: 2889
Polar bear energetic and behavioral strategies on land with implications for surviving the ice-free period
Declining Arctic sea ice is increasing polar bear land use. Polar bears on land are thought to minimize activity to conserve energy. Here, we measure the daily energy expenditure (DEE), diet, behavior, movement, and body composition changes of 20 different polar bears on land over 19–23 days from August to September (2019–2022) in Manitoba, Canada. Polar bears on land exhibited a 5.2-fold range in
Authors
Anthony M. Pagano, Karyn D. Rode, Nicholas J. Lunn, David McGeachy, Stephen N. Atkinson, Sean D. Farley, Joy A. Erlenbach, Charles T. Robbins
Rayleigh step-selection functions and connections to continuous-time mechanistic movement models
BackgroundThe process known as ecological diffusion emerges from a first principles view of animal movement, but ecological diffusion and other partial differential equation models can be difficult to fit to data. Step-selection functions (SSFs), on the other hand, have emerged as powerful practical tools for ecologists studying the movement and habitat selection of animals.MethodsSSFs typically i
Authors
Joseph Michael Eisaguirre, Perry J. Williams, Mevin B. Hooten
Long-term storage at -20°C compromises fatty acid composition of polar bear adipose biopsies
This study aimed to gain insight into the influence of storage time and temperature on fatty acid (FA) signatures of biopsies of marine mammal adipose/blubber tissues. To examine storage effects, biopsy-type slices from larger pieces of adipose tissues from 2 polar bears Ursus maritimus were stored at either -20 or -80°C and subsequently analyzed for fatty acid composition initially (before storag
Authors
Rose Lacombe, Todd C. Atwood, Elizabeth Peacock, Anais Remili, Rune Dietz, Christian Sonne, Melissa McKinney
Approaches for using CMIP projections in climate model ensembles to address the ‘hot model’ problem
Several recent generation global-climate models were found to have anomalously high climate sensitivities and may not be useful for certain applications. Four approaches for developing ensembles of climate projections for applications that address this issue are:Using an “all models” approach;Screening using equilibrium climate sensitivity and (or) transient climate response;Bayesian model averagi
Authors
Ryan Boyles, Catherine A. Nikiel, Brian W. Miller, Jeremy Littell, Adam J. Terando, Imtiaz Rangwala, Jay R. Alder, Derek H. Rosendahl, Adrienne M. Wootten
Identifying indicators of polar bear population status
Monitoring trends in large mammal populations is a fundamental component of wildlife management and conservation. However, direct estimates of population size and vital rates of large mammals can be logistically challenging and expensive. Indicators that reflect trends in abundance, therefore, can be valuable tools for supporting population monitoring. Polar bears have a relatively simple life his
Authors
Karyn D. Rode, Ryan R. Wilson, Justin A. Crawford, Lori T. Quakenbush
Sea-ice conditions predict polar bear land use around military installations in Alaska
Polar bears (Ursus maritimus) are threatened by sea-ice loss due to climate change, which is concurrently opening the Arctic to natural resource extraction and a broader scope of national security responsibilities. Mitigating the risk of human–bear conflicts is an emerging challenge as many polar bears spend longer ice-free summers on land where they have limited access to food and come into more
Authors
Eric V. Regehr, Kristin L. Laidre, Todd C. Atwood, Harry Stern, Benjamin R. Cohen
A decade of death and other dynamics: Deepening perspectives on the diversity and distribution of sea stars and wasting
Mass mortality events provide valuable insight into biological extremes and also ecological interactions more generally. The sea star wasting epidemic that began in 2013 catalyzed study of the microbiome, genetics, population dynamics, and community ecology of several high-profile species inhabiting the northeastern Pacific but exposed a dearth of information on the diversity, distributions, and i
Authors
Michael Dawson, Paige Duffin, Melina Giakoumis, Lauren M Schiebelhut, Rodrigo Beas-Luna, Keith Bosley, Rita Castilho, Christine Ewers-Saucedo, Katie Gavenus, Aimee Keller, Brenda Konar, John L. Largier, Julio Lorda, Melissa Miner, Monica Moritsch, Sergio Navarette, Peter T. Raimondi, Sarah Beth Traiger, Monica Turner, John Wares
Alaska's climate sensitive Yukon-Kuskokwim Delta supports seven million Arctic-breeding shorebirds, including the majority of six North American populations
Baseline information about declining North American shorebird populations is essential to determine the effects of global warming at low-lying coastal areas of the Arctic and subarctic, where numerous taxa breed, and to assess population recovery throughout their range. We estimated population sizes on the Yukon-Kuskokwim Delta in western Alaska on the eastern edge of the Bering Sea. We conducted
Authors
James E. Lyons, Stephen C. Brown, Sarah T. Saalfeld, James A. Johnson, Brad A. Andres, Kristine M. Sowl, Robert E. Gill, Brian J. McCaffery, Lindall Kidd, Metta McGarvey, Brad Winn, H. River Gates, Diane A. Granfors, Richard B. Lanctot
How to handle glacier area change in geodetic mass balance
Innovations in geodesy enable widespread analysis of glacier surface elevation change and geodetic mass balance. However, coincident glacier area data are less widely available, causing inconsistent handling of glacier area change. Here we quantify the bias introduced into meters water equivalent (m w.e.) specific geodetic mass balance results when using a fixed, maximum glacier area, and illustra
Authors
Caitlyn Florentine, Louis C. Sass, Christopher J. McNeil, Emily Baker, Shad O'Neel
Environmental DNA as a tool for better understanding the distribution, abundance, and health of Atlantic and Pacific salmon
The development and application of approaches to detect and quantify environmental DNA (eDNA) have potential to improve our understanding of the distribution, abundance, and health of Atlantic Salmon Salmo salar and Pacific salmon Oncorhynchus spp. Here, we review 61 articles focusing on eDNA applications pertaining to salmon occupying natural habitat and aquaculture facilities in the context of a
Authors
Andrew M. Ramey, Cherie Marie Mckeeman, Eleni Leto Petrou, Damian M. Menning, Ora L. Russ, Andrés López
Site fidelity of migratory shorebirds facing habitat deterioration: Insights from satellite tracking and mark-resighting
BackgroundSite fidelity, the tendency to return to a previously visited site, is commonly observed in migratory birds. This behaviour would be advantageous if birds returning to the same site, benefit from their previous knowledge about local resources. However, when habitat quality declines at a site over time, birds with lower site fidelity might benefit from a tendency to move to sites with bet
Authors
Ying-Chi Chan, David Tsz-Chung Chan, Lee Tibbitts, Chris J. Hassell, Theunis Piersma
Rapid population decline in McKay's Bunting, an Alaskan endemic, highlights the species’ current status relative to international standards for vulnerable species
The McKay’s Bunting (Plectrophenax hyperboreus) is endemic to Alaska, breeds solely on the remote and uninhabited St. Matthew and Hall islands (332 km2) in the central Bering Sea, and is designated as a species of high conservation concern due to its small population size and restricted range. A previous hypothesized population estimate (~2,800—6,000 individuals) was greatly increased (~31,200 ind
Authors
Rachel M. Richardson, Courtney L. Amundson, James A. Johnson, Marc D. Romano, Audrey R. Taylor, Michael D. Fleming, Steven M. Matsuoka