Skip to main content
U.S. flag

An official website of the United States government

Todd Atwood, Ph.D.

Spatial ecology, population ecology, predator-prey dynamics, polar bear ecology

Professional Experience

  • 2012 - Present    Research Wildlife Biologist and Project Leader, USGS Alaska Science Center, Anchorage, AK

  • 2008 - 2012        Research Wildlife Biologist, USDA/APHIS/WS/National Wildlife Research Center, Fort Collins, CO

  • 2006 - 2008       Research Biologist, Research Branch, Arizona Game and Fish Department, Phoenix, AZ

  • 2006                    Biological Technician, USDA/National Wildlife Research Center, Fort Collins, CO

Education and Certifications

  • Ph.D.  2006   Utah State University   Wildlife Biology

  • M.S.    2002   Purdue University        Wildlife Ecology

  • B.S.     1999   Purdue University        Wildlife Ecology

Affiliations and Memberships

  • The Wildlife Society

  • International Association for Bear Research and Management

  • American Society of Mammalogists

Science and Products

link
Female and two cubs polar bears on the sea ice

Polar Bear Maternal Denning

Pregnant polar bears enter maternity dens in October/November, give birth to cubs in December/January, and exit dens in March/April. Historically, most polar bears from the Southern Beaufort Sea (SBS) population constructed maternity dens on the sea ice. Over the last three decades, as sea ice has become thinner and prone to fragmentation, there has been a landward shift in the distribution of...
By
Energy & Wildlife, Alaska Science Center
link

Polar Bear Maternal Denning

Pregnant polar bears enter maternity dens in October/November, give birth to cubs in December/January, and exit dens in March/April. Historically, most polar bears from the Southern Beaufort Sea (SBS) population constructed maternity dens on the sea ice. Over the last three decades, as sea ice has become thinner and prone to fragmentation, there has been a landward shift in the distribution of...
Learn More
link
Polar bear appears to walk on top of rippled gray water. Just behind it are very large breaking waves below a gray-blue sky.

Polar Bear Population Dynamics

Information on the status and trends of polar bear populations are needed to inform management of polar bears under US laws and international agreements. The USGS maintains a long-term research program focused on the population dynamics of the southern Beaufort Sea polar bear population. In addition, the USGS collaborates with the US Fish and Wildlife Service in population studies in the Chukchi...
By
Alaska Science Center
link

Polar Bear Population Dynamics

Information on the status and trends of polar bear populations are needed to inform management of polar bears under US laws and international agreements. The USGS maintains a long-term research program focused on the population dynamics of the southern Beaufort Sea polar bear population. In addition, the USGS collaborates with the US Fish and Wildlife Service in population studies in the Chukchi...
Learn More
link
A polar bear walks across rubble ice in the Alaska portion of the southern Beaufort Sea

Distribution and Movements of Polar Bears

Polar bears are tied to the sea ice for nearly all of their life cycle functions. Most important of these is foraging, or access to food. Polar bears almost exclusively eat seals, and they are equally as dependent upon the sea for their nutrition as are seals, whales, and other aquatic mammals. Polar bears are not aquatic, however, and their only access to the seals is from the surface of the sea...
By
Alaska Science Center
link

Distribution and Movements of Polar Bears

Polar bears are tied to the sea ice for nearly all of their life cycle functions. Most important of these is foraging, or access to food. Polar bears almost exclusively eat seals, and they are equally as dependent upon the sea for their nutrition as are seals, whales, and other aquatic mammals. Polar bears are not aquatic, however, and their only access to the seals is from the surface of the sea...
Learn More
link
Polar bear still hunting at a seal breathing hole

Health and Energetics of Polar Bears

Research in this focal area is centered on (i) collecting data on a variety of systems that help determine and mediate polar bear health and energetics, and (ii) developing monitoring and surveillance programs for detecting changes in population health over time. Additionally, this work will allow us to develop an understanding of how polar bear populations will respond to a variety of stressors...
By
Alaska Science Center
link

Health and Energetics of Polar Bears

Research in this focal area is centered on (i) collecting data on a variety of systems that help determine and mediate polar bear health and energetics, and (ii) developing monitoring and surveillance programs for detecting changes in population health over time. Additionally, this work will allow us to develop an understanding of how polar bear populations will respond to a variety of stressors...
Learn More
link
Polar bear mother and two cubs on the Beaufort Sea ice.

Polar Bear Research

Polar bears (Ursus maritimus) are one of 4 marine mammal species managed by the U.S. Department of Interior. The USGS Alaska Science Center leads long–term research on polar bears to inform local, state, national and international policy makers regarding conservation of the species and its habitat. Our studies, ongoing since 1985, are focused on population dynamics, health and energetics...
By
Ecosystems, Energy & Wildlife, Wildlife Program, Alaska Science Center
link

Polar Bear Research

Polar bears (Ursus maritimus) are one of 4 marine mammal species managed by the U.S. Department of Interior. The USGS Alaska Science Center leads long–term research on polar bears to inform local, state, national and international policy makers regarding conservation of the species and its habitat. Our studies, ongoing since 1985, are focused on population dynamics, health and energetics...
Learn More

Polar Bear Fall Coastal Survey Data from the Southern Beaufort Sea of Alaska, 2010-2013

This data set is one table with observations of polar bears located during aerial surveys along the coast and barrier islands of the southern Beaufort Seas during fall, 2010-2013. Survey flights were conducted using A-Star B2 and Bell 206 helicopters at an average altitude of 300 feet AGL and an average speed of 50 miles per hour. Survey crews searched for polar bears using coastal and inland tran
By
Alaska Science Center

Mapping data of Polar Bear (Ursus maritimus) maternal den habitat, Arctic Coastal Plain, Alaska

These are geospatial data that characterize the distribution of polar bear denning habitat on the National Petroleum Reserve-Alaska (NPR-A), the 1002 Area of the Arctic National Wildlife Refuge and the coastal plain of northern Alaska between the Colville River and the Alaska/Canada border.
By
Alaska Science Center

Pathogen and Contaminant Exposure Data from Southern Beaufort Sea Polar Bears, 2007-2014

These were data collected from polar bears from the Southern Beaufort Sea during the spring between 2007 and 2014. Data include individual ID, capture date, sex and age class, whether individuals visited bowhead whale carrion sites, exposure status relative to five pathogens, and concentrations of certain persistent organic pollutants.
By
Alaska Science Center

Polar Bear Continuous Time-Correlated Random Walk (CTCRW) Location Data Derived from Satellite Location Data, Southern Beaufort Sea, 1986-2016

This dataset consists of one table with predicted locations of adult female polar bears. Locations were derived by a Continuous Time-Correlated Random Walk (CTCRW) model using satellite tracking radio-collared adult female polar bears captured and instrumented in the southern Beaufort Sea, 1986–2016.
By
Alaska Science Center

Innate Immunity and Stress and Reproductive Hormone Metrics for Southern Beaufort Sea Polar Bears, 2013-2015

These were data collected from polar bears from the Southern Beaufort Sea during the spring between 2013 and 2015. Data include individual identification, demographic characteristics, year, status for the current and prior year regarding use of land, concentrations of stress response and reproductive hormones, blood-based biomarker measures indicative of fasting, body mass index, and body conditio
By
Alaska Science Center

Serum Urea and Creatinine Levels of Spring-Caught Polar Bears (Ursus maritimus) in the Southern Beaufort and Chukchi Seas

These data are serum urea nitrogen and creatinine levels for polar bears captured in the southern Beaufort Sea 1983-2016 and the Chukchi Sea 1987-1993 and 2008-2017. The dataset includes relevant information about the bears that were captured including the latitude and longitude of their capture location, capture date, age class and sex, the age and number of cubs accompanying an adult female, and
By
Alaska Science Center

Multistate capture and search data from the southern Beaufort Sea polar bear population in Alaska, 2001-2016

This data release contains two tables of information on polar bear distributions in the southern Beaufort Sea during spring, from 2001 to 2016. One table provides location (classified into 5 broad regions) of individual bears during the spring. The other table presents the aerial search effort by year and area.
By
Alaska Science Center

Polar Bear Microsatellite Data Southern Beaufort Sea 2010-2013

This data set provides Polar Bear microsatellite genotypes derived from twenty loci (G1A, G10B, G10C, CXX110, G1D, G10H, G10J, G10L, G10M, MSUT2, MU59, G10P, 145P07, CPH9, CXX20, MU50, MU51, G10X, CXX173, G10U). Samples for microsatellite genetic analysis were collected from polar bears from the southern Beaufort Sea during the spring and fall, 2010-2013. Tissue samples were collected from capture
By
Alaska Science Center

Satellite Location and Tri-axial Accelerometer Data from Adult Female Polar Bears (Ursus maritimus) in the Southern Beaufort Sea, April-October 2014

These data are from 5 adult female polar bears instrumented in the southern Beaufort Sea, April to October 2014. The dataset is comprised of two data packages: 1) contains GPS and Argos locations collected by satellite-linked GPS receivers mounted on external collars, and 2) contains archival logger data including measures of tri-axial acceleration and conductivity. These data were collected to ga
By
Alaska Science Center

Serological Data on Influenza A from Birds and Mammals on the Arctic Coastal Plain of Northern Alaska, 2011-2017

These data (in two spreadsheets) are the results of screening for influenza A viruses (IAV) in blood from wild animals that utilize the Arctic region of Alaska. 758 blood samples from nine wildlife species (3 mammal, 6 waterbird) were collected in Arctic Alaska, 2011-2017. Two different tests were used and the results are presented in separate spreadsheets. All blood samples were screened for IAV
By
Alaska Science Center

U.S. Geological Survey Polar Bear Mark-Recapture Records, Alaska Portion of the Southern Beaufort Sea, 2001-2010

These data were collected by the U.S. Geological Survey, Alaska Science Center, Polar Bear Research Program as part of long-term on the southern Beaufort Sea polar bear population.
By
Alaska Science Center
Filter Total Items: 60

The role of satellite telemetry data in 21st century conservation of polar bears (Ursus maritimus)

Satellite telemetry (ST) has played a critical role in the management and conservation of polar bears (Ursus maritimus) over the last 50 years. ST data provide biological information relevant to subpopulation delineation, movements, habitat use, maternal denning, health, human-bear interactions, and accurate estimates of vital rates and abundance. Given that polar bears are distributed at low dens
By
Ecosystems, Alaska Science Center

Distinct gut microbiomes in two polar bear subpopulations inhabiting different sea ice ecoregions

Gut microbiomes were analyzed by 16S rRNA gene metabarcoding for polar bears (Ursus maritimus) from the southern Beaufort Sea (SB), where sea ice loss has led to increased use of land-based food resources by bears, and from East Greenland (EG), where persistent sea ice has allowed hunting of ice-associated prey nearly year-round. SB polar bears showed a higher number of total (940 vs. 742) and uni
By
Ecosystems, Alaska Science Center

Diet-driven mercury contamination is associated with polar bear gut microbiota

The gut microbiota may modulate the disposition and toxicity of environmental contaminants within a host but, conversely, contaminants may also impact gut bacteria. Such contaminant-gut microbial connections, which could lead to alteration of host health, remain poorly known and are rarely studied in free-ranging wildlife. The polar bear (Ursus maritimus) is a long-lived, wide-ranging apex predato
By
Ecosystems, Alaska Science Center

Long-term variation in polar bear body condition and maternal investment relative to a changing environment

In the Arctic, warming air and ocean temperatures have resulted in substantial changes to sea ice, which is primary habitat for polar bears (Ursus maritimus). Reductions in extent, duration, and thickness have altered sea ice dynamics, which influences the ability of polar bears to reliably access marine mammal prey. Because nutritional condition is closely linked to population vital rates, a prog
By
Ecosystems, Alaska Science Center

Effects of sea ice decline and summer land use on polar bear home range size in the Beaufort Sea

Animals responding to habitat loss and fragmentation may increase their home ranges to offset declines in localized resources or they may decrease their home ranges and switch to alternative resources. In many regions of the Arctic, polar bears (Ursus maritimus) exhibit some of the largest home ranges of any quadrupedal mammal. Polar bears are presently experiencing a rapid decline in Arctic sea i
By
Ecosystems, Alaska Science Center

Survival and abundance of polar bears in Alaska’s Beaufort Sea, 2001–2016

The Arctic Ocean is undergoing rapid transformation toward a seasonally ice-free ecosystem. As ice-adapted apex predators, polar bears (Ursus maritimus) are challenged to cope with ongoing habitat degradation and changes in their prey base driven by food-web response to climate warming. Knowledge of polar bear response to environmental change is necessary to understand ecosystem dynamics and infor
By
Ecosystems, Alaska Science Center

Human-polar bear interactions

Human-wildlife interactions (HWI) are driven fundamentally by overlapping space and resources. As competition intensifies, the likelihood of interaction and conflict increases. In turn, conflict may impede conservation efforts by lowering social tolerance of wildlife, especially when human-wildlife conflict (HWC) poses a threat to human safety and economic well-being. Thus, mitigating conflict is
By
Ecosystems, Alaska Science Center

Measuring adrenal and reproductive hormones in hair from southern Beaufort Sea polar bears (Ursus maritimus)

Polar bears (Ursus maritimus) use sea ice to access marine mammal prey. In Alaska’s Southern Beaufort Sea, the declining availability of sea ice habitat in summer and fall has reduced opportunities for polar bears to routinely hunt on the ice for seals, their primary prey. This reduced access to prey may result in physiological stress with subsequent potential consequences to reproductive function
By
Ecosystems, Alaska Science Center

How Is climate change affecting polar bears and giant pandas?

Anthropogenic greenhouse gas emissions are the primary cause of climate change and an estimated increase of 3.7 to 4.8 °C is predicted by the year 2100 if emissions continue at current levels. Polar bears (Ursus maritimus) and giant pandas (Ailuropoda melanoleuca) provide an interesting comparison study of the impact of climate change on bear species. While polar bears and giant pandas are arguabl
By
Ecosystems, Alaska Science Center

Analyses on subpopulation abundance and annual number of maternal dens for the U.S. Fish and Wildlife Service on polar bears (Ursus maritimus) in the southern Beaufort Sea, Alaska

The long-term persistence of polar bears (Ursus maritimus) is threatened by sea-ice loss due to climate change, which is concurrently providing an opportunity in the Arctic for increased anthropogenic activities including natural resource extraction. Mitigating the risk of those activities, which can adversely affect the population dynamics of the southern Beaufort Sea (SBS) subpopulation, is an e
By
Ecosystems, Alaska Science Center

Identifying reliable indicators of fitness in polar bears

Animal structural body size and condition are often measured to evaluate individual health, identify responses to environmental change and food availability, and relate food availability to effects on reproduction and survival. A variety of condition metrics have been developed but relationships between these metrics and vital rates are rarely validated. Identifying an optimal approach to estimate
By
Ecosystems, Alaska Science Center, Molecular Ecology Laboratory

Fatty acid-based diet estimates suggest ringed seal remain the main prey of southern Beaufort Sea polar bears despite recent use of onshore food resources

Polar bears (Ursus maritimus) from the southern Beaufort Sea (SB) subpopulation have traditionally fed predominantly upon ice‐seals; however, as the proportion of the subpopulation using onshore habitat has recently increased, foraging on land‐based resources, including remains of subsistence‐harvested bowhead whales (Balaena mysticetus) and colonial nesting seabirds has been observed. Adipose tis
By
Ecosystems, Alaska Science Center

Pre-USGS Publications

Algeo, T. P., D. Slate, R. M. Caron, T. C. Atwood, S. Recuenco, M. Ducey, R. B. Chipman, and M. Palace. 2017. Modeling raccoon (Procyon lotor) habitat connectivity to identify potential corridors for rabies spread. Tropical Medicine and Infectious Diseases 44. doi:10.3390/tropicalmed203044.
Atwood, T. C., E. Peacock, K. M. Lillie, R. R. Wilson, and S. Miller. 2015. Demographic composition and behavior of polar bears summering on shore in Alaska. USGS Administrative Report, 26 p.
Beasley, J. C., T. C. Atwood, M. E. Byrne, K. C. VerCauteren, S. R. Johnson, and O. E. Rhodes, Jr. 2015. A behaviorally-explicit approach for evaluating vaccine baits to mesopredators to control epizootics in fragmented landscapes. PLoS One 10:e0113206. doi:10.1371/journal.pone.0113206.
Anderson, A., S. A. Shwiff, R. B. Chipman, T. C. Atwood, T. Cozzens, F. Fillo, R. Hale, B. Hatch, J. Maki, O. E. Rhodes, Jr, E. E. Rees, C. E. Rupprecht, R. Tinline, K. C. VerCauteren, and D. Slate. 2014. Forecasting the spread of raccoon rabies using a purpose-specific group decision-making process. Human-Wildlife Interactions 8(1):130-138.
Slate, D., R. B. Chipman, T. P. Algeo, S. A. Mills, K. M. Nelson, C. K. Croson, E. J. Dubovi, R. W. Renshaw, K. C. VerCauteren, T. C. Atwood, S. Johnson, and C. E. Rupprecht. 2014. Safety and immunogenicity in the first field trial with ONRAB in raccoons in the United States. Journal of Wildlife Diseases 50(3):582-595. doi:10.7589/2013-08-207.
Kunkel, K. E., T. K. Ruth, T. C. Atwood, D. H. Pletscher, and M. G. Hornocker. 2013. Assessing the value of wolves and cougars as conservation surrogates by linking carnivore hunting success with landscape characteristics. Animal Conservation 16:32-40. doi:10.1111/j.1469-1795.2012.00568.x.
Beasley, J. D., W. S. Beatty, T. C. Atwood, S. Johnson, and O. E. Rhodes, Jr. 2012. A comparison of methods for estimating raccoon abundance: Implications for disease vaccination programs. Journal of Wildlife Management 76(6):1290-1297. doi:10.1002/jwmg.379.
Atwood, T. C. and S. W. Breck. 2012. Carnivores, Conflict, and Conservation: Defining the Landscape of Conflict. Pages 99-118 in F. I. Álvares and G. E. Mata, (eds.). Carnivores: Species, Conservation, and Management. Nova Publishers.
Atwood, T. C., T. L. Fry, and B. R. Leland. 2011. Partitioning of a limited resource by sympatric carnivores in the Chihuahuan Desert and the implications for disease transmission. Journal of Wildlife Management 75:1609-1615.
Atwood, T. C., J. K. Young, J. P. Beckmann, S. W. Breck, O. E. Rhodes, Jr, J. A. Fike, and K. D. Bristow. 2011. Modeling connectivity of black bears in a desert sky island archipelago. Biological Conservation 144(12):2851-2862. doi:10.1016/j.biocon.2011.08.002.
Fry, T. L., T. C. Atwood, and M. R. Dunbar. 2010. Utility of rhodamine B as a biomarker in raccoons. Human-Wildlife Interactions 4:275-282.
Atwood, T. C. and E. M. Gese. 2010. Importance of resource selection and social behaviour to partitioning of hostile space by sympatric canids. Journal of Mammalogy 91:490-499.
Atwood, T. C., T. J. DeLiberto, H. J. Smith, J. Stevenson, and K. C. VerCauteren. 2009. Raccoon spatial ecology related to cattle and bovine tuberculosis. Journal of Wildlife Management 73:647-654.
Atwood, T. C., E. M. Gese, and K. E. Kunkel. 2009. Spatial decomposition of predation risk in a multiple-predator multiple-prey system. Journal of Wildlife Management 73:876-884.
Atwood, T. C. and E. M. Gese. 2008. Coyotes (Canis latrans) and recolonizing wolves (Canis lupus): Social rank mediates risk-conditional behaviour at ungulate carcasses. Animal Behaviour 75:753-762.
VerCauteren, K. C., T. C. Atwood, T. J. DeLiberto, H. J. Smith, J. Stevenson, T. Gidlewski, and B. V. Thomsen. 2008. Sentinel-based surveillance of coyotes to detect bovine tuberculosis in Michigan. Emerging Infectious Diseases 14:1862-1869.
Atwood, T. C., K. C. VerCauteren, T. J. DeLiberto, H. J. Smith, and J. Stevenson. 2007. Coyotes as a potential sentinel species to detect bovine tuberculosis (Mycobacterium bovis) infection in white-tailed deer in Michigan. Journal of Wildlife Management 71:1545-1554.
Atwood, T. C., E. M. Gese, and K. E. Kunkel. 2007. Comparative patterns of predation by cougars and recolonizing wolves. Journal of Wildlife Management 71:1098-1106.
Atwood, T. C. 2006. The influence of habitat patch attributes on coyote group size and interaction in a fragmented landscape. Canadian Journal of Zoology 84:80-87.
Atwood, T. C. 2006. Behavioral interactions between wolves, Canis lupus, and coyotes, Canis latrans, at ungulate carcasses in southwest Montana. Western North American Naturalist 66:390-394.
Atwood, T. C., H. P. Weeks, Jr., and T. M. Gehring. 2004. Spatial ecology of coyotes along a suburban-to-rural gradient. Journal of Wildlife Management 85:1000-1009.
Swihart, R. K., T. C. Atwood, J. R. Goheen, D. A. Scheiman, K. E. Munroe, and T. M. Gehring. 2003. Patch occupancy in North American mammals: Is patchiness in the eye of the beholder? . Journal of Biogeography 30:1259-1279.
Atwood, T. C. and H. P. Weeks, Jr.. 2003. Sex-specific patterns of mineral lick preference in white-tailed deer. Northeastern Naturalist 10:409-414.
Atwood, T. C. and H. P. Weeks, Jr.. 2002. Sex- and age-specific patterns of mineral lick use by white-tailed deer. American Midland Naturalist 148:289-296.
Atwood, T. C. and H. P. Weeks, Jr.. 2002. Facultative dyad formation in adult male coyotes. Northeastern Naturalist 9:353-358.
link

Polar Bear Outlook Favorable Under Certain Scenarios

“The scenarios predicted by our models are encouraging in that there are clear actions that humans can take to improve the chances that healthy polar...

Read Article
link

Observing Polar Bears from Space

Monitoring wildlife in the Arctic is difficult. Study areas are cold, barren and often inaccessible. For decades scientists have struggled to study...

Read Article

Science and Products

  • Science
    link
    Female and two cubs polar bears on the sea ice

    Polar Bear Maternal Denning

    Pregnant polar bears enter maternity dens in October/November, give birth to cubs in December/January, and exit dens in March/April. Historically, most polar bears from the Southern Beaufort Sea (SBS) population constructed maternity dens on the sea ice. Over the last three decades, as sea ice has become thinner and prone to fragmentation, there has been a landward shift in the distribution of...
    By
    Energy & Wildlife, Alaska Science Center
    link

    Polar Bear Maternal Denning

    Pregnant polar bears enter maternity dens in October/November, give birth to cubs in December/January, and exit dens in March/April. Historically, most polar bears from the Southern Beaufort Sea (SBS) population constructed maternity dens on the sea ice. Over the last three decades, as sea ice has become thinner and prone to fragmentation, there has been a landward shift in the distribution of...
    Learn More
    link
    Polar bear appears to walk on top of rippled gray water. Just behind it are very large breaking waves below a gray-blue sky.

    Polar Bear Population Dynamics

    Information on the status and trends of polar bear populations are needed to inform management of polar bears under US laws and international agreements. The USGS maintains a long-term research program focused on the population dynamics of the southern Beaufort Sea polar bear population. In addition, the USGS collaborates with the US Fish and Wildlife Service in population studies in the Chukchi...
    By
    Alaska Science Center
    link

    Polar Bear Population Dynamics

    Information on the status and trends of polar bear populations are needed to inform management of polar bears under US laws and international agreements. The USGS maintains a long-term research program focused on the population dynamics of the southern Beaufort Sea polar bear population. In addition, the USGS collaborates with the US Fish and Wildlife Service in population studies in the Chukchi...
    Learn More
    link
    A polar bear walks across rubble ice in the Alaska portion of the southern Beaufort Sea

    Distribution and Movements of Polar Bears

    Polar bears are tied to the sea ice for nearly all of their life cycle functions. Most important of these is foraging, or access to food. Polar bears almost exclusively eat seals, and they are equally as dependent upon the sea for their nutrition as are seals, whales, and other aquatic mammals. Polar bears are not aquatic, however, and their only access to the seals is from the surface of the sea...
    By
    Alaska Science Center
    link

    Distribution and Movements of Polar Bears

    Polar bears are tied to the sea ice for nearly all of their life cycle functions. Most important of these is foraging, or access to food. Polar bears almost exclusively eat seals, and they are equally as dependent upon the sea for their nutrition as are seals, whales, and other aquatic mammals. Polar bears are not aquatic, however, and their only access to the seals is from the surface of the sea...
    Learn More
    link
    Polar bear still hunting at a seal breathing hole

    Health and Energetics of Polar Bears

    Research in this focal area is centered on (i) collecting data on a variety of systems that help determine and mediate polar bear health and energetics, and (ii) developing monitoring and surveillance programs for detecting changes in population health over time. Additionally, this work will allow us to develop an understanding of how polar bear populations will respond to a variety of stressors...
    By
    Alaska Science Center
    link

    Health and Energetics of Polar Bears

    Research in this focal area is centered on (i) collecting data on a variety of systems that help determine and mediate polar bear health and energetics, and (ii) developing monitoring and surveillance programs for detecting changes in population health over time. Additionally, this work will allow us to develop an understanding of how polar bear populations will respond to a variety of stressors...
    Learn More
    link
    Polar bear mother and two cubs on the Beaufort Sea ice.

    Polar Bear Research

    Polar bears (Ursus maritimus) are one of 4 marine mammal species managed by the U.S. Department of Interior. The USGS Alaska Science Center leads long–term research on polar bears to inform local, state, national and international policy makers regarding conservation of the species and its habitat. Our studies, ongoing since 1985, are focused on population dynamics, health and energetics...
    By
    Ecosystems, Energy & Wildlife, Wildlife Program, Alaska Science Center
    link

    Polar Bear Research

    Polar bears (Ursus maritimus) are one of 4 marine mammal species managed by the U.S. Department of Interior. The USGS Alaska Science Center leads long–term research on polar bears to inform local, state, national and international policy makers regarding conservation of the species and its habitat. Our studies, ongoing since 1985, are focused on population dynamics, health and energetics...
    Learn More
  • Data

    Polar Bear Fall Coastal Survey Data from the Southern Beaufort Sea of Alaska, 2010-2013

    This data set is one table with observations of polar bears located during aerial surveys along the coast and barrier islands of the southern Beaufort Seas during fall, 2010-2013. Survey flights were conducted using A-Star B2 and Bell 206 helicopters at an average altitude of 300 feet AGL and an average speed of 50 miles per hour. Survey crews searched for polar bears using coastal and inland tran
    By
    Alaska Science Center

    Mapping data of Polar Bear (Ursus maritimus) maternal den habitat, Arctic Coastal Plain, Alaska

    These are geospatial data that characterize the distribution of polar bear denning habitat on the National Petroleum Reserve-Alaska (NPR-A), the 1002 Area of the Arctic National Wildlife Refuge and the coastal plain of northern Alaska between the Colville River and the Alaska/Canada border.
    By
    Alaska Science Center

    Pathogen and Contaminant Exposure Data from Southern Beaufort Sea Polar Bears, 2007-2014

    These were data collected from polar bears from the Southern Beaufort Sea during the spring between 2007 and 2014. Data include individual ID, capture date, sex and age class, whether individuals visited bowhead whale carrion sites, exposure status relative to five pathogens, and concentrations of certain persistent organic pollutants.
    By
    Alaska Science Center

    Polar Bear Continuous Time-Correlated Random Walk (CTCRW) Location Data Derived from Satellite Location Data, Southern Beaufort Sea, 1986-2016

    This dataset consists of one table with predicted locations of adult female polar bears. Locations were derived by a Continuous Time-Correlated Random Walk (CTCRW) model using satellite tracking radio-collared adult female polar bears captured and instrumented in the southern Beaufort Sea, 1986–2016.
    By
    Alaska Science Center

    Innate Immunity and Stress and Reproductive Hormone Metrics for Southern Beaufort Sea Polar Bears, 2013-2015

    These were data collected from polar bears from the Southern Beaufort Sea during the spring between 2013 and 2015. Data include individual identification, demographic characteristics, year, status for the current and prior year regarding use of land, concentrations of stress response and reproductive hormones, blood-based biomarker measures indicative of fasting, body mass index, and body conditio
    By
    Alaska Science Center

    Serum Urea and Creatinine Levels of Spring-Caught Polar Bears (Ursus maritimus) in the Southern Beaufort and Chukchi Seas

    These data are serum urea nitrogen and creatinine levels for polar bears captured in the southern Beaufort Sea 1983-2016 and the Chukchi Sea 1987-1993 and 2008-2017. The dataset includes relevant information about the bears that were captured including the latitude and longitude of their capture location, capture date, age class and sex, the age and number of cubs accompanying an adult female, and
    By
    Alaska Science Center

    Multistate capture and search data from the southern Beaufort Sea polar bear population in Alaska, 2001-2016

    This data release contains two tables of information on polar bear distributions in the southern Beaufort Sea during spring, from 2001 to 2016. One table provides location (classified into 5 broad regions) of individual bears during the spring. The other table presents the aerial search effort by year and area.
    By
    Alaska Science Center

    Polar Bear Microsatellite Data Southern Beaufort Sea 2010-2013

    This data set provides Polar Bear microsatellite genotypes derived from twenty loci (G1A, G10B, G10C, CXX110, G1D, G10H, G10J, G10L, G10M, MSUT2, MU59, G10P, 145P07, CPH9, CXX20, MU50, MU51, G10X, CXX173, G10U). Samples for microsatellite genetic analysis were collected from polar bears from the southern Beaufort Sea during the spring and fall, 2010-2013. Tissue samples were collected from capture
    By
    Alaska Science Center

    Satellite Location and Tri-axial Accelerometer Data from Adult Female Polar Bears (Ursus maritimus) in the Southern Beaufort Sea, April-October 2014

    These data are from 5 adult female polar bears instrumented in the southern Beaufort Sea, April to October 2014. The dataset is comprised of two data packages: 1) contains GPS and Argos locations collected by satellite-linked GPS receivers mounted on external collars, and 2) contains archival logger data including measures of tri-axial acceleration and conductivity. These data were collected to ga
    By
    Alaska Science Center

    Serological Data on Influenza A from Birds and Mammals on the Arctic Coastal Plain of Northern Alaska, 2011-2017

    These data (in two spreadsheets) are the results of screening for influenza A viruses (IAV) in blood from wild animals that utilize the Arctic region of Alaska. 758 blood samples from nine wildlife species (3 mammal, 6 waterbird) were collected in Arctic Alaska, 2011-2017. Two different tests were used and the results are presented in separate spreadsheets. All blood samples were screened for IAV
    By
    Alaska Science Center

    U.S. Geological Survey Polar Bear Mark-Recapture Records, Alaska Portion of the Southern Beaufort Sea, 2001-2010

    These data were collected by the U.S. Geological Survey, Alaska Science Center, Polar Bear Research Program as part of long-term on the southern Beaufort Sea polar bear population.
    By
    Alaska Science Center
  • Publications
    Filter Total Items: 60

    The role of satellite telemetry data in 21st century conservation of polar bears (Ursus maritimus)

    Satellite telemetry (ST) has played a critical role in the management and conservation of polar bears (Ursus maritimus) over the last 50 years. ST data provide biological information relevant to subpopulation delineation, movements, habitat use, maternal denning, health, human-bear interactions, and accurate estimates of vital rates and abundance. Given that polar bears are distributed at low dens
    By
    Ecosystems, Alaska Science Center

    Distinct gut microbiomes in two polar bear subpopulations inhabiting different sea ice ecoregions

    Gut microbiomes were analyzed by 16S rRNA gene metabarcoding for polar bears (Ursus maritimus) from the southern Beaufort Sea (SB), where sea ice loss has led to increased use of land-based food resources by bears, and from East Greenland (EG), where persistent sea ice has allowed hunting of ice-associated prey nearly year-round. SB polar bears showed a higher number of total (940 vs. 742) and uni
    By
    Ecosystems, Alaska Science Center

    Diet-driven mercury contamination is associated with polar bear gut microbiota

    The gut microbiota may modulate the disposition and toxicity of environmental contaminants within a host but, conversely, contaminants may also impact gut bacteria. Such contaminant-gut microbial connections, which could lead to alteration of host health, remain poorly known and are rarely studied in free-ranging wildlife. The polar bear (Ursus maritimus) is a long-lived, wide-ranging apex predato
    By
    Ecosystems, Alaska Science Center

    Long-term variation in polar bear body condition and maternal investment relative to a changing environment

    In the Arctic, warming air and ocean temperatures have resulted in substantial changes to sea ice, which is primary habitat for polar bears (Ursus maritimus). Reductions in extent, duration, and thickness have altered sea ice dynamics, which influences the ability of polar bears to reliably access marine mammal prey. Because nutritional condition is closely linked to population vital rates, a prog
    By
    Ecosystems, Alaska Science Center

    Effects of sea ice decline and summer land use on polar bear home range size in the Beaufort Sea

    Animals responding to habitat loss and fragmentation may increase their home ranges to offset declines in localized resources or they may decrease their home ranges and switch to alternative resources. In many regions of the Arctic, polar bears (Ursus maritimus) exhibit some of the largest home ranges of any quadrupedal mammal. Polar bears are presently experiencing a rapid decline in Arctic sea i
    By
    Ecosystems, Alaska Science Center

    Survival and abundance of polar bears in Alaska’s Beaufort Sea, 2001–2016

    The Arctic Ocean is undergoing rapid transformation toward a seasonally ice-free ecosystem. As ice-adapted apex predators, polar bears (Ursus maritimus) are challenged to cope with ongoing habitat degradation and changes in their prey base driven by food-web response to climate warming. Knowledge of polar bear response to environmental change is necessary to understand ecosystem dynamics and infor
    By
    Ecosystems, Alaska Science Center

    Human-polar bear interactions

    Human-wildlife interactions (HWI) are driven fundamentally by overlapping space and resources. As competition intensifies, the likelihood of interaction and conflict increases. In turn, conflict may impede conservation efforts by lowering social tolerance of wildlife, especially when human-wildlife conflict (HWC) poses a threat to human safety and economic well-being. Thus, mitigating conflict is
    By
    Ecosystems, Alaska Science Center

    Measuring adrenal and reproductive hormones in hair from southern Beaufort Sea polar bears (Ursus maritimus)

    Polar bears (Ursus maritimus) use sea ice to access marine mammal prey. In Alaska’s Southern Beaufort Sea, the declining availability of sea ice habitat in summer and fall has reduced opportunities for polar bears to routinely hunt on the ice for seals, their primary prey. This reduced access to prey may result in physiological stress with subsequent potential consequences to reproductive function
    By
    Ecosystems, Alaska Science Center

    How Is climate change affecting polar bears and giant pandas?

    Anthropogenic greenhouse gas emissions are the primary cause of climate change and an estimated increase of 3.7 to 4.8 °C is predicted by the year 2100 if emissions continue at current levels. Polar bears (Ursus maritimus) and giant pandas (Ailuropoda melanoleuca) provide an interesting comparison study of the impact of climate change on bear species. While polar bears and giant pandas are arguabl
    By
    Ecosystems, Alaska Science Center

    Analyses on subpopulation abundance and annual number of maternal dens for the U.S. Fish and Wildlife Service on polar bears (Ursus maritimus) in the southern Beaufort Sea, Alaska

    The long-term persistence of polar bears (Ursus maritimus) is threatened by sea-ice loss due to climate change, which is concurrently providing an opportunity in the Arctic for increased anthropogenic activities including natural resource extraction. Mitigating the risk of those activities, which can adversely affect the population dynamics of the southern Beaufort Sea (SBS) subpopulation, is an e
    By
    Ecosystems, Alaska Science Center

    Identifying reliable indicators of fitness in polar bears

    Animal structural body size and condition are often measured to evaluate individual health, identify responses to environmental change and food availability, and relate food availability to effects on reproduction and survival. A variety of condition metrics have been developed but relationships between these metrics and vital rates are rarely validated. Identifying an optimal approach to estimate
    By
    Ecosystems, Alaska Science Center, Molecular Ecology Laboratory

    Fatty acid-based diet estimates suggest ringed seal remain the main prey of southern Beaufort Sea polar bears despite recent use of onshore food resources

    Polar bears (Ursus maritimus) from the southern Beaufort Sea (SB) subpopulation have traditionally fed predominantly upon ice‐seals; however, as the proportion of the subpopulation using onshore habitat has recently increased, foraging on land‐based resources, including remains of subsistence‐harvested bowhead whales (Balaena mysticetus) and colonial nesting seabirds has been observed. Adipose tis
    By
    Ecosystems, Alaska Science Center

    Pre-USGS Publications

    Algeo, T. P., D. Slate, R. M. Caron, T. C. Atwood, S. Recuenco, M. Ducey, R. B. Chipman, and M. Palace. 2017. Modeling raccoon (Procyon lotor) habitat connectivity to identify potential corridors for rabies spread. Tropical Medicine and Infectious Diseases 44. doi:10.3390/tropicalmed203044.
    Atwood, T. C., E. Peacock, K. M. Lillie, R. R. Wilson, and S. Miller. 2015. Demographic composition and behavior of polar bears summering on shore in Alaska. USGS Administrative Report, 26 p.
    Beasley, J. C., T. C. Atwood, M. E. Byrne, K. C. VerCauteren, S. R. Johnson, and O. E. Rhodes, Jr. 2015. A behaviorally-explicit approach for evaluating vaccine baits to mesopredators to control epizootics in fragmented landscapes. PLoS One 10:e0113206. doi:10.1371/journal.pone.0113206.
    Anderson, A., S. A. Shwiff, R. B. Chipman, T. C. Atwood, T. Cozzens, F. Fillo, R. Hale, B. Hatch, J. Maki, O. E. Rhodes, Jr, E. E. Rees, C. E. Rupprecht, R. Tinline, K. C. VerCauteren, and D. Slate. 2014. Forecasting the spread of raccoon rabies using a purpose-specific group decision-making process. Human-Wildlife Interactions 8(1):130-138.
    Slate, D., R. B. Chipman, T. P. Algeo, S. A. Mills, K. M. Nelson, C. K. Croson, E. J. Dubovi, R. W. Renshaw, K. C. VerCauteren, T. C. Atwood, S. Johnson, and C. E. Rupprecht. 2014. Safety and immunogenicity in the first field trial with ONRAB in raccoons in the United States. Journal of Wildlife Diseases 50(3):582-595. doi:10.7589/2013-08-207.
    Kunkel, K. E., T. K. Ruth, T. C. Atwood, D. H. Pletscher, and M. G. Hornocker. 2013. Assessing the value of wolves and cougars as conservation surrogates by linking carnivore hunting success with landscape characteristics. Animal Conservation 16:32-40. doi:10.1111/j.1469-1795.2012.00568.x.
    Beasley, J. D., W. S. Beatty, T. C. Atwood, S. Johnson, and O. E. Rhodes, Jr. 2012. A comparison of methods for estimating raccoon abundance: Implications for disease vaccination programs. Journal of Wildlife Management 76(6):1290-1297. doi:10.1002/jwmg.379.
    Atwood, T. C. and S. W. Breck. 2012. Carnivores, Conflict, and Conservation: Defining the Landscape of Conflict. Pages 99-118 in F. I. Álvares and G. E. Mata, (eds.). Carnivores: Species, Conservation, and Management. Nova Publishers.
    Atwood, T. C., T. L. Fry, and B. R. Leland. 2011. Partitioning of a limited resource by sympatric carnivores in the Chihuahuan Desert and the implications for disease transmission. Journal of Wildlife Management 75:1609-1615.
    Atwood, T. C., J. K. Young, J. P. Beckmann, S. W. Breck, O. E. Rhodes, Jr, J. A. Fike, and K. D. Bristow. 2011. Modeling connectivity of black bears in a desert sky island archipelago. Biological Conservation 144(12):2851-2862. doi:10.1016/j.biocon.2011.08.002.
    Fry, T. L., T. C. Atwood, and M. R. Dunbar. 2010. Utility of rhodamine B as a biomarker in raccoons. Human-Wildlife Interactions 4:275-282.
    Atwood, T. C. and E. M. Gese. 2010. Importance of resource selection and social behaviour to partitioning of hostile space by sympatric canids. Journal of Mammalogy 91:490-499.
    Atwood, T. C., T. J. DeLiberto, H. J. Smith, J. Stevenson, and K. C. VerCauteren. 2009. Raccoon spatial ecology related to cattle and bovine tuberculosis. Journal of Wildlife Management 73:647-654.
    Atwood, T. C., E. M. Gese, and K. E. Kunkel. 2009. Spatial decomposition of predation risk in a multiple-predator multiple-prey system. Journal of Wildlife Management 73:876-884.
    Atwood, T. C. and E. M. Gese. 2008. Coyotes (Canis latrans) and recolonizing wolves (Canis lupus): Social rank mediates risk-conditional behaviour at ungulate carcasses. Animal Behaviour 75:753-762.
    VerCauteren, K. C., T. C. Atwood, T. J. DeLiberto, H. J. Smith, J. Stevenson, T. Gidlewski, and B. V. Thomsen. 2008. Sentinel-based surveillance of coyotes to detect bovine tuberculosis in Michigan. Emerging Infectious Diseases 14:1862-1869.
    Atwood, T. C., K. C. VerCauteren, T. J. DeLiberto, H. J. Smith, and J. Stevenson. 2007. Coyotes as a potential sentinel species to detect bovine tuberculosis (Mycobacterium bovis) infection in white-tailed deer in Michigan. Journal of Wildlife Management 71:1545-1554.
    Atwood, T. C., E. M. Gese, and K. E. Kunkel. 2007. Comparative patterns of predation by cougars and recolonizing wolves. Journal of Wildlife Management 71:1098-1106.
    Atwood, T. C. 2006. The influence of habitat patch attributes on coyote group size and interaction in a fragmented landscape. Canadian Journal of Zoology 84:80-87.
    Atwood, T. C. 2006. Behavioral interactions between wolves, Canis lupus, and coyotes, Canis latrans, at ungulate carcasses in southwest Montana. Western North American Naturalist 66:390-394.
    Atwood, T. C., H. P. Weeks, Jr., and T. M. Gehring. 2004. Spatial ecology of coyotes along a suburban-to-rural gradient. Journal of Wildlife Management 85:1000-1009.
    Swihart, R. K., T. C. Atwood, J. R. Goheen, D. A. Scheiman, K. E. Munroe, and T. M. Gehring. 2003. Patch occupancy in North American mammals: Is patchiness in the eye of the beholder? . Journal of Biogeography 30:1259-1279.
    Atwood, T. C. and H. P. Weeks, Jr.. 2003. Sex-specific patterns of mineral lick preference in white-tailed deer. Northeastern Naturalist 10:409-414.
    Atwood, T. C. and H. P. Weeks, Jr.. 2002. Sex- and age-specific patterns of mineral lick use by white-tailed deer. American Midland Naturalist 148:289-296.
    Atwood, T. C. and H. P. Weeks, Jr.. 2002. Facultative dyad formation in adult male coyotes. Northeastern Naturalist 9:353-358.
  • News
    link

    Polar Bear Outlook Favorable Under Certain Scenarios

    “The scenarios predicted by our models are encouraging in that there are clear actions that humans can take to improve the chances that healthy polar...

    Read Article
    link

    Observing Polar Bears from Space

    Monitoring wildlife in the Arctic is difficult. Study areas are cold, barren and often inaccessible. For decades scientists have struggled to study...

    Read Article