USGS - science for a changing world

Alaska Science Center

white dothome: white dotproducts: white dotoutreach/media: white dotcontact us:   white dotinternal:

Forecasting Pacific walrus responses to climate change

Walrus hauled out on shore near Pt. Lay in the Eastern Chukchi Sea - Photo by Tony Fischbach, USGSThe Pacific walrus is a benthic feeding, ice-associated pinniped that ranges over the continental shelves of the Bering and Chukchi seas.  The extent of summer sea ice in the Chukchi Sea has decreased substantially in recent years and this trend is projected to continue.  Changes in the distribution of seasonal sea ice will likely affect walrus distribution and behavior and could affect the status of this population.  Based on this and concerns about the effects of large-scale industrial developments that are expected to take place in walrus habitat, the U.S. Fish and Wildlife Service has recently designated this the Pacific walrus as warranted for listing under the Endangered Species Act, with a final decision scheduled for 2017.  Department of Interior agencies need information on likely responses of walruses to climate change and other potential impacts as a basis for management of this trust species.  As a part of the USGS Changing Arctic Ecosystem Initiative, this research is focused on developing a comprehensive approach for forecasting status of the Pacific walrus population under changing climate scenarios.  We are developing and integrating bioenergetic and population dynamics models to provide mechanistic linkages between forecasted changes in sea ice and benthic prey and population level consequences for walruses.  There is almost no existing information about bioenergetic or demographic parameters for walruses, there have been no previous attempts to model their bioenergetics, and existing population models are rudimentary.  Technology for long-term monitoring of individual walruses is not currently available and other approaches for estimating the necessary parameters must be developed.


Noren, S. R., M. S. Udevitz, L. Triggs, J. Paschke, L. Oland, and C. V. Jay. 2015. Identifying a reliable blubber measurement site to assess body condition in a marine mammal with topographically variable blubber, the Pacific walrus. Marine Mammal Science 31(2):658-676. doi:10.1111/mms.12186 [Details] [Full Publication]

Taylor, R. L. and M. S. Udevitz. 2015. Demography of the Pacific walrus (Odobenus rosmarus divergens): 1974-2006. Marine Mammal Science 31(1):231-254. doi:10.1111/mms.12156 [Details] [Full Publication]

Van Hemert, C. R., P. L. Flint, M. S. Udevitz, J. C. Koch, T. C. Atwood, K. L. Oakley, and J. A. Pearce. 2015. Forecasting wildlife response to rapid warming in the Alaskan Arctic. BioScience In Press. doi:10.1093/biosci/biv069 [Details] [Full Publication]

Noren, S. R., M. S. Udevitz, and C. V. Jay. 2014. Energy demands for maintenance, growth, pregnancy, and lactation of female Pacific walruses (Odobenus rosmarus divergens). Physiological and Biochemical Zoology 87(6). doi:10.1086/678237 [Details] [Full Publication]

Udevitz, M. S., R. L. Taylor, J. Garlich-Miller, L. T. Quakenbush, and J. Snyder. 2013. Potential population-level effects of increased haulout-related mortality of Pacific walrus calves. Polar Biology 36(2):291-298. doi:10.1007/s00300-012-1259-3 [Details] [Full Publication]

Noren, S. R., M. S. Udevitz, and C. V. Jay. 2012. Bioenergetics model for estimating food requirements of female Pacific walruses (Odobenus rosmarus divergens). Marine Ecology Progress Series 460:261-275. doi:10.3354/meps09706 [Details] [Full Publication]

Oakley, K. L., M. E. Whalen, D. C. Douglas, M. S. Udevitz, T. C. Atwood, and C. V. Jay. 2012. Changing Arctic Ecosystems - Polar bear and walrus response to the rapid decline in Arctic sea ice. USGS Fact Sheet 2012-3131, 4 p. [Details] [Full Publication]


Accessibility FOIA Privacy Policies and Notices logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information:
Page Last Modified: December 06 2016 10:54:55.