George Durner, Ph.D. (Former Employee)
Science and Products
Filter Total Items: 71
The use of sea ice habitat by female polar bears in the Beaufort Sea
Polar bears (Ursus maritimus) depend on ice-covered seas to satisfy life history requirements. Modern threats to polar bears include oil spills in the marine environment and changes in ice composition resulting from climate change. Managers need practical models that explain the distribution of bears in order to assess the impacts of these threats. We used stepwise procedures to create resource se
Authors
George M. Durner, Steven C. Amstrup, Ryan M. Nielson, Trent McDonald
Using the bootstrap and fast Fourier transform to estimate confidence intervals of 2D kernel densities
No abstract available.
Authors
John W. Kern, Trent L. McDonald, Steven C. Amstrup, George M. Durner, Wallace P. Erickson
Comparing movement patterns of satellite-tagged male and female polar bears
Satellite radiotelemetry has provided great insights into the movements and behaviors of polar bears (Ursus maritimus). The diameter of the neck of adult male polar bears exceeds that of their head, however, and radio collars slip off. This has limited collection of movement information to that from radio-collared females. To overcome this difficulty and gather information about their movements, w
Authors
Steven C. Amstrup, George M. Durner, T. L. McDonald, D.M. Mulcahy, G.W. Garner
Remote identification of polar bear maternal den habitat in northern Alaska
Polar bears (Ursus maritimus) give birth in dens of ice and snow to protect their altricial young. During the snow-free season, we visited 25 den sites located previously by radiotelemetry and characterized the den site physiognomy. Seven dens occurred in habitats with minimal relief. Eighteen dens (72%) were in coastal and river banks. These "banks" were identifiable on aerial photographs. We the
Authors
George M. Durner, Steven C. Amstrup, Ken J. Ambrosius
Movements and distribution of polar bears in the Beaufort sea
We fitted 173 satellite radio collars (platform transmitter terminals) to 121 adult female polar bears in the Beaufort Sea and relocated the bears 44 736 times between 1985 and 1995. We regularly resighted many instrumented bears so that we could ascertain whether changes in movements or distribution were related to reproductive status. Mean short-term movement rates were less than 2 km/h for all
Authors
Steven C. Amstrup, George M. Durner, I. Stirling, N.J. Lunn, F. Messier
Estimating the impacts of oil spills on polar bears
The polar bear is the apical predator and universal symbol of the Arctic. They occur throughout the Arctic marine environment wherever sea ice is prevalent. In the southern Beaufort Sea, polar bears are most common within the area of the outer continental shelf, where the hunt for seals along persistent leads and openings in the ice. Polar bears are a significant cultural and subsistence component
Authors
George M. Durner, Steven C. Amstrup, Trent L. McDonald
Caribou distribution during the post-calving period in relation to infrastructure in the Prudhoe Bay oil field, Alaska
There is concern that caribou (Rangifer tarandus) may avoid roads and facilities (i.e., infrastructure) in the Prudhoe Bay oil field (PBOF) in northern Alaska, and that this avoidance can have negative effects on the animals. We quantified the relationship between caribou distribution and PBOF infrastructure during the post-calving period (mid-June to mid-August) with aerial surveys from 1990 to 1
Authors
Matthew A. Cronin, Steven C. Amstrup, George M. Durner, Lynn E. Noel, Trent L. McDonald, Warren B. Ballard
Mass and body-dimension relationships of polar bears in northern Alaska
Models developed from morphometric parameters are useful for estimating body mass (M) of captured wild ursids. The accuracy of those models, however, may depend on sex, season, and geographic location of the population. We tested the suitability of reported models to predict mass of polar bears (Ursus maritimus) captured in northern Alaska, but found that models developed for other populations per
Authors
George M. Durner, Steven C. Amstrup
Polar bear research in the Beaufort Sea
Current research is designed to determine the status of the polar bear population in the Beaufort Sea and adjacent areas. One goal is to determine how polar bears are distributed relative to each other and habitat features, and to define population boundaries. Another goal is to determine the population size and trend, and assess how present and future management issues may affect thetrend. Specif
Authors
Steven C. Amstrup, George M. Durner
Movements of a polar bear from northern Alaska to northern Greenland
Using satellite telemetry, we monitored the movements of an adult female polar bear (Ursus maritimus) as she traveled from the Alaskan Beaufort Sea coast to northern Greenland. She is the first polar bear known to depart the Beaufort Sea region for an extended period, and the first polar bear known to move between Alaska and Greenland. This bear traveled for four months across the polar basin and
Authors
George M. Durner, Steven C. Amstrup
Survival rates of radio-collared female polar bears and their dependent young
Polar bears are hunted throughout most of their range. In addition to
hunting, polar bears of the Beaufort Sea region are exposed to mineral
and hydrocarbon extraction and related human activities such as
shipping, road building, and seismic testing. As human populations
increase and demands for polar bears and other arctic resources
escalate, reliable estimates of survivo
Authors
Steven C. Amstrup, George M. Durner
Non-USGS Publications**
Amstrup, S. C., G. M. Durner, A. S. Fischbach, K. S. Simac, and G. W. York. 2011. Polar Bear Research in the Beaufort Sea. Proceedings: Bear Taxanomic Group Workshop on Ursids in Captivity. American Zoological Society Annual Meeting. Detroit, MI, USA.
Durner, G. M., D. C. Douglas, R. M. Nielson, S. C. Amstrup, and T. L. McDonald. 2007. Predicting the future distribution of Polar Bear Habitat in the polar basin from resource selection functions applied to 21st century general circulation model projections of sea ice. USGS Administrative Report, 61 p. doi:10.3133/70174076
Bergen, S., G. M. Durner, D. C. Douglas, and S. C. Amstrup. 2007. Predicting movements of female polar bears between summer sea ice foraging habitats and terrestrial denning habitats of Alaska in the 21st century: Proposed methodology and pilot assessment. USGS Administrative Report, 24 p.
Durner, G. M., S. C. Amstrup, G. York, E. V. Regehr, K. S. Simac, T. S. Smith, S. T. Partridge, T. W. Bentzen, K. S. Amstrup, and D. C. Douglas. 2005. Report on research progress in Alaska. Proceedings: 15th Annual meeting of joint commissioners and technical advisors of the Inuvialiut Game Council and North Slope Borough. Edmonton, Alberta, Canada.
Amstrup, S. C., G. M. Durner, E. V. Regehr, G. W. York, K. S. Simac, T. S. Smith, S. T. Partridge, and D. C. Douglas. 2004. Polar Bear Research in the Beaufort Sea. February 2004, Winnipeg, Manitoba. Proceedings: Canadian Polar Bear Technical Committee.
Amstrup, S. C., G. M. Durner, A. S. Fischbach, G. W. York, K. S. Simac, T. S. Smith, S. T. Partridge, and D. C. Douglas. 2003. Polar Bear Research in the Beaufort Sea. February 2003, Edmonton, Alberta. Proceedings: Canadian Polar Bear Technical Committee.
Durner, G. M., S. C. Amstrup, R. Neilson, and T. L. McDonald. 2003. The use of sea ice habitat by female polar bears in the Beaufort Sea. Pages 60-61 in Proceedings of the Ninth MMS Information Transfer Meeting. MMS OCS Study 2003-042, 118 p.
Amstrup, S. C., G. M. Durner, A. S. Fischbach, K. S. Simac, and G. W. York. 2002. Polar Bear Research in the Beaufort Sea. Pages 109-125 in edited by N. J. Lunn, S. Schliebe and E. W. Born, (eds.), Occasional Paper IUCN Specialists Survey Commission 26. Proceedings: 13th Working Meeting of the IUCN/SSC Polar Bear Specialist Group, 23-28 June 2001. Nuuk, Greenland.
Durner, G. M., S. C. Amstrup, A. S. Fischbach, G. S. York, and K. S. Simac. 2002. Polar bear research in the Beaufort Sea. Proceedings: Canadian Polar Bear Technical Committee, 9-10 Feb 2002. Iqualuit, Canada.
Amstrup, S. C., G. M. Durner, A. S. Fischbach, K. S. Simac, and G. W. York. 2002. Polar Bear Research in the Beaufort Sea. Proceedings of the Bear Taxanomic Group Workshop on Ursids in Captivity. Annual Meeting of the American Zoological Society, Detroit, MI, April 27 - 29, 2001.
Amstrup, S. C., G. M. Durner, and T. L. McDonald. 2002. Volume III, Appendix J 1, Liberty Development and Production Plan. Draft Environmental Impact Statement. Minerals Management Service, Alaska Outer Continental Shelf Region OCS EIS/EA MMS 2001-001.
Amstrup, S. C. and G. M. Durner. 1999. Polar Bear Research in the Beaufort Sea. Pages 131-139 in A. E. Derocher, (ed.), Occasional Paper IUCN Specialists Survey Commission 19. Proceedings: IUCN/SSC Polar Bear Specialist Group
Amstrup, S. C. and G. M. Durner. 1999. Polar bear research in the Beaufort Sea. Proceedings: Canadian Polar Bear Technical Committee
Amstrup, S. C. and G. M. Durner. 1998. Polar bear research in the Beaufort Sea. Pages 47-52 in Proceedings: Canadian Polar Bear Technical Committee
Amstrup, S. C. and G. M. Durner. 1998. Polar bear research in the Beaufort Sea. Pages 131-139 in A. E. Derocher, G. W. Garner, N. J. Lunn, and O. Wiig, (eds.). International Union for Conservation of Nature and Natural Resources, Gland, Switzerland. IUCN/SSC Occasional Paper 19. 159 pp. Proceedings: 12th Working Meeting of the IUCN/SSC Polar Bear Specialist Group Oslo, Norway.
Amstrup, S. C. and G. M. Durner. 1998. Identification of polar bear den habitat in northern Alaska. Pages 141-145 in A. E. Derocher, G. W. Garner, N. J. Lunn, and O. Wiig, (eds.). International Union for Conservation of Nature and Natural Resources, Gland, Switzerland. IUCN/SSC Occasional Paper 19. 159 pp. Proceedings: 12th Working Meeting of the IUCN/SSC Polar Bear Specialist Group Oslo, Norway.
Durner, G. M. and J. E. Gates. 1993. Spatial Ecology of Black Rat Snakes on Remington Farms, Maryland. Journal of Wildlife Management 57(4):812-826.
Amstrup, S. C. and G. M. Durner. 1992. Temporal and geographic variation of maternity denning among polar bears of the Beaufort Sea. US Fish and Wildlife Service, Pages 198-206 in T. R. Mc Cabe, B. Griffith, N. E. Walsh, and D. D. Young, (eds.). Terrestrial Research: 1002 area - Arctic National Wildlife Refuge, Interim Report, 1988-1990, 432 p.
Amstrup, S. C. and G. M. Durner. 1992. Polar bear maternity denning on the Arctic National Wildlife Refuge, Alaska. US Fish and Wildlife Service, Pages 189-197 in T. R. Mc Cabe, B. Griffith, N. E. Walsh, and D. D. Young, (eds.). Terrestrial Research: 1002 area - Arctic National Wildlife Refuge, Interim Report, 1988-1990, 432 p.
Amstrup, S. C. and G. M. Durner. 1992. Responses of maternal polar bears to human activities in Alaska. US Fish and Wildlife Service, Pages 198-206 in T. R. Mc Cabe, B. Griffith, N. E. Walsh, and D. D. Young, (eds.). Terrestrial Research: 1002 area - Arctic National Wildlife Refuge, Interim Report, 1988-1990, 432 p.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
Filter Total Items: 71
The use of sea ice habitat by female polar bears in the Beaufort Sea
Polar bears (Ursus maritimus) depend on ice-covered seas to satisfy life history requirements. Modern threats to polar bears include oil spills in the marine environment and changes in ice composition resulting from climate change. Managers need practical models that explain the distribution of bears in order to assess the impacts of these threats. We used stepwise procedures to create resource se
Authors
George M. Durner, Steven C. Amstrup, Ryan M. Nielson, Trent McDonald
Using the bootstrap and fast Fourier transform to estimate confidence intervals of 2D kernel densities
No abstract available.
Authors
John W. Kern, Trent L. McDonald, Steven C. Amstrup, George M. Durner, Wallace P. Erickson
Comparing movement patterns of satellite-tagged male and female polar bears
Satellite radiotelemetry has provided great insights into the movements and behaviors of polar bears (Ursus maritimus). The diameter of the neck of adult male polar bears exceeds that of their head, however, and radio collars slip off. This has limited collection of movement information to that from radio-collared females. To overcome this difficulty and gather information about their movements, w
Authors
Steven C. Amstrup, George M. Durner, T. L. McDonald, D.M. Mulcahy, G.W. Garner
Remote identification of polar bear maternal den habitat in northern Alaska
Polar bears (Ursus maritimus) give birth in dens of ice and snow to protect their altricial young. During the snow-free season, we visited 25 den sites located previously by radiotelemetry and characterized the den site physiognomy. Seven dens occurred in habitats with minimal relief. Eighteen dens (72%) were in coastal and river banks. These "banks" were identifiable on aerial photographs. We the
Authors
George M. Durner, Steven C. Amstrup, Ken J. Ambrosius
Movements and distribution of polar bears in the Beaufort sea
We fitted 173 satellite radio collars (platform transmitter terminals) to 121 adult female polar bears in the Beaufort Sea and relocated the bears 44 736 times between 1985 and 1995. We regularly resighted many instrumented bears so that we could ascertain whether changes in movements or distribution were related to reproductive status. Mean short-term movement rates were less than 2 km/h for all
Authors
Steven C. Amstrup, George M. Durner, I. Stirling, N.J. Lunn, F. Messier
Estimating the impacts of oil spills on polar bears
The polar bear is the apical predator and universal symbol of the Arctic. They occur throughout the Arctic marine environment wherever sea ice is prevalent. In the southern Beaufort Sea, polar bears are most common within the area of the outer continental shelf, where the hunt for seals along persistent leads and openings in the ice. Polar bears are a significant cultural and subsistence component
Authors
George M. Durner, Steven C. Amstrup, Trent L. McDonald
Caribou distribution during the post-calving period in relation to infrastructure in the Prudhoe Bay oil field, Alaska
There is concern that caribou (Rangifer tarandus) may avoid roads and facilities (i.e., infrastructure) in the Prudhoe Bay oil field (PBOF) in northern Alaska, and that this avoidance can have negative effects on the animals. We quantified the relationship between caribou distribution and PBOF infrastructure during the post-calving period (mid-June to mid-August) with aerial surveys from 1990 to 1
Authors
Matthew A. Cronin, Steven C. Amstrup, George M. Durner, Lynn E. Noel, Trent L. McDonald, Warren B. Ballard
Mass and body-dimension relationships of polar bears in northern Alaska
Models developed from morphometric parameters are useful for estimating body mass (M) of captured wild ursids. The accuracy of those models, however, may depend on sex, season, and geographic location of the population. We tested the suitability of reported models to predict mass of polar bears (Ursus maritimus) captured in northern Alaska, but found that models developed for other populations per
Authors
George M. Durner, Steven C. Amstrup
Polar bear research in the Beaufort Sea
Current research is designed to determine the status of the polar bear population in the Beaufort Sea and adjacent areas. One goal is to determine how polar bears are distributed relative to each other and habitat features, and to define population boundaries. Another goal is to determine the population size and trend, and assess how present and future management issues may affect thetrend. Specif
Authors
Steven C. Amstrup, George M. Durner
Movements of a polar bear from northern Alaska to northern Greenland
Using satellite telemetry, we monitored the movements of an adult female polar bear (Ursus maritimus) as she traveled from the Alaskan Beaufort Sea coast to northern Greenland. She is the first polar bear known to depart the Beaufort Sea region for an extended period, and the first polar bear known to move between Alaska and Greenland. This bear traveled for four months across the polar basin and
Authors
George M. Durner, Steven C. Amstrup
Survival rates of radio-collared female polar bears and their dependent young
Polar bears are hunted throughout most of their range. In addition to
hunting, polar bears of the Beaufort Sea region are exposed to mineral
and hydrocarbon extraction and related human activities such as
shipping, road building, and seismic testing. As human populations
increase and demands for polar bears and other arctic resources
escalate, reliable estimates of survivo
Authors
Steven C. Amstrup, George M. Durner
Non-USGS Publications**
Amstrup, S. C., G. M. Durner, A. S. Fischbach, K. S. Simac, and G. W. York. 2011. Polar Bear Research in the Beaufort Sea. Proceedings: Bear Taxanomic Group Workshop on Ursids in Captivity. American Zoological Society Annual Meeting. Detroit, MI, USA.
Durner, G. M., D. C. Douglas, R. M. Nielson, S. C. Amstrup, and T. L. McDonald. 2007. Predicting the future distribution of Polar Bear Habitat in the polar basin from resource selection functions applied to 21st century general circulation model projections of sea ice. USGS Administrative Report, 61 p. doi:10.3133/70174076
Bergen, S., G. M. Durner, D. C. Douglas, and S. C. Amstrup. 2007. Predicting movements of female polar bears between summer sea ice foraging habitats and terrestrial denning habitats of Alaska in the 21st century: Proposed methodology and pilot assessment. USGS Administrative Report, 24 p.
Durner, G. M., S. C. Amstrup, G. York, E. V. Regehr, K. S. Simac, T. S. Smith, S. T. Partridge, T. W. Bentzen, K. S. Amstrup, and D. C. Douglas. 2005. Report on research progress in Alaska. Proceedings: 15th Annual meeting of joint commissioners and technical advisors of the Inuvialiut Game Council and North Slope Borough. Edmonton, Alberta, Canada.
Amstrup, S. C., G. M. Durner, E. V. Regehr, G. W. York, K. S. Simac, T. S. Smith, S. T. Partridge, and D. C. Douglas. 2004. Polar Bear Research in the Beaufort Sea. February 2004, Winnipeg, Manitoba. Proceedings: Canadian Polar Bear Technical Committee.
Amstrup, S. C., G. M. Durner, A. S. Fischbach, G. W. York, K. S. Simac, T. S. Smith, S. T. Partridge, and D. C. Douglas. 2003. Polar Bear Research in the Beaufort Sea. February 2003, Edmonton, Alberta. Proceedings: Canadian Polar Bear Technical Committee.
Durner, G. M., S. C. Amstrup, R. Neilson, and T. L. McDonald. 2003. The use of sea ice habitat by female polar bears in the Beaufort Sea. Pages 60-61 in Proceedings of the Ninth MMS Information Transfer Meeting. MMS OCS Study 2003-042, 118 p.
Amstrup, S. C., G. M. Durner, A. S. Fischbach, K. S. Simac, and G. W. York. 2002. Polar Bear Research in the Beaufort Sea. Pages 109-125 in edited by N. J. Lunn, S. Schliebe and E. W. Born, (eds.), Occasional Paper IUCN Specialists Survey Commission 26. Proceedings: 13th Working Meeting of the IUCN/SSC Polar Bear Specialist Group, 23-28 June 2001. Nuuk, Greenland.
Durner, G. M., S. C. Amstrup, A. S. Fischbach, G. S. York, and K. S. Simac. 2002. Polar bear research in the Beaufort Sea. Proceedings: Canadian Polar Bear Technical Committee, 9-10 Feb 2002. Iqualuit, Canada.
Amstrup, S. C., G. M. Durner, A. S. Fischbach, K. S. Simac, and G. W. York. 2002. Polar Bear Research in the Beaufort Sea. Proceedings of the Bear Taxanomic Group Workshop on Ursids in Captivity. Annual Meeting of the American Zoological Society, Detroit, MI, April 27 - 29, 2001.
Amstrup, S. C., G. M. Durner, and T. L. McDonald. 2002. Volume III, Appendix J 1, Liberty Development and Production Plan. Draft Environmental Impact Statement. Minerals Management Service, Alaska Outer Continental Shelf Region OCS EIS/EA MMS 2001-001.
Amstrup, S. C. and G. M. Durner. 1999. Polar Bear Research in the Beaufort Sea. Pages 131-139 in A. E. Derocher, (ed.), Occasional Paper IUCN Specialists Survey Commission 19. Proceedings: IUCN/SSC Polar Bear Specialist Group
Amstrup, S. C. and G. M. Durner. 1999. Polar bear research in the Beaufort Sea. Proceedings: Canadian Polar Bear Technical Committee
Amstrup, S. C. and G. M. Durner. 1998. Polar bear research in the Beaufort Sea. Pages 47-52 in Proceedings: Canadian Polar Bear Technical Committee
Amstrup, S. C. and G. M. Durner. 1998. Polar bear research in the Beaufort Sea. Pages 131-139 in A. E. Derocher, G. W. Garner, N. J. Lunn, and O. Wiig, (eds.). International Union for Conservation of Nature and Natural Resources, Gland, Switzerland. IUCN/SSC Occasional Paper 19. 159 pp. Proceedings: 12th Working Meeting of the IUCN/SSC Polar Bear Specialist Group Oslo, Norway.
Amstrup, S. C. and G. M. Durner. 1998. Identification of polar bear den habitat in northern Alaska. Pages 141-145 in A. E. Derocher, G. W. Garner, N. J. Lunn, and O. Wiig, (eds.). International Union for Conservation of Nature and Natural Resources, Gland, Switzerland. IUCN/SSC Occasional Paper 19. 159 pp. Proceedings: 12th Working Meeting of the IUCN/SSC Polar Bear Specialist Group Oslo, Norway.
Durner, G. M. and J. E. Gates. 1993. Spatial Ecology of Black Rat Snakes on Remington Farms, Maryland. Journal of Wildlife Management 57(4):812-826.
Amstrup, S. C. and G. M. Durner. 1992. Temporal and geographic variation of maternity denning among polar bears of the Beaufort Sea. US Fish and Wildlife Service, Pages 198-206 in T. R. Mc Cabe, B. Griffith, N. E. Walsh, and D. D. Young, (eds.). Terrestrial Research: 1002 area - Arctic National Wildlife Refuge, Interim Report, 1988-1990, 432 p.
Amstrup, S. C. and G. M. Durner. 1992. Polar bear maternity denning on the Arctic National Wildlife Refuge, Alaska. US Fish and Wildlife Service, Pages 189-197 in T. R. Mc Cabe, B. Griffith, N. E. Walsh, and D. D. Young, (eds.). Terrestrial Research: 1002 area - Arctic National Wildlife Refuge, Interim Report, 1988-1990, 432 p.
Amstrup, S. C. and G. M. Durner. 1992. Responses of maternal polar bears to human activities in Alaska. US Fish and Wildlife Service, Pages 198-206 in T. R. Mc Cabe, B. Griffith, N. E. Walsh, and D. D. Young, (eds.). Terrestrial Research: 1002 area - Arctic National Wildlife Refuge, Interim Report, 1988-1990, 432 p.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government