William leads research on wildlife population modeling, movement ecology, and space use with an emphasis on migratory waterbirds
Professional Experience
2021 – Present, Research Wildlife Biologist, U.S. Geological Survey, Upper Midwest Environmental Sciences Center, La Crosse, Wisconsin
2016 – 2021, Wildlife Biologist, U.S. Fish and Wildlife Service, Marine Mammals Management, Anchorage, Alaska
2014 – 2016, Research Wildlife Biologist, U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska
2012 – 2014, Post-doctoral Fellow, University of Missouri, Missouri Cooperative Fish and Wildlife Research Unit
Education and Certifications
Ph.D., Purdue University, Wildlife Science, 2012
M.S., Eastern Illinois University, Biological Sciences, 2008
B.S., University of Missouri, Fisheries and Wildlife Science, 2005
Affiliations and Memberships*
The Wildlife Society
Society for Marine Mammalogy
Science and Products
Q&A: Estimates of Abundance for Pacific Walrus
Walrus Haulout and In-water Activity Levels Relative to Vessel Interactions in the Chukchi Sea, 2012-2015
Pacific Walrus Behavior Data and Associated Chukchi Sea Ice Observations and Projections for use with Bioenergetics Models to Forecast Walrus Body Condition
Estimating Pacific walrus abundance and survival with multievent mark-recapture models
Restoration of Gavia immer (common loon) in Minnesota—2021 annual report
Walrus haul-out and in water activity levels relative to sea ice availability in the Chukchi Sea
How will predicted land-use change affect waterfowl spring stopover ecology? Inferences from an individual-based model
Space use of a dominant Arctic vertebrate: Effects of prey, sea ice, and land on Pacific walrus resource selection
An evaluation of behavior inferences from Bayesian state-space models: A case study with the Pacific walrus
Science and Products
- Science
Q&A: Estimates of Abundance for Pacific Walrus
The Pacific walrus ranges across the Bering and Chukchi seas during the year. This wide geographic distribution makes it difficult to estimate Pacific walrus population abundance. However, recent technological advances in genetics and drone imagery have generated precise regional and range-wide abundance estimates. - Data
Walrus Haulout and In-water Activity Levels Relative to Vessel Interactions in the Chukchi Sea, 2012-2015
These data were used to evaluate effects of vessel exposure on Pacific walrus (Odobenus rosmarus divergens) behaviors. We obtained greater than 120,000 hours of location and behavior (foraging, in-water not foraging, hauled out) data from 218 satellite-tagged walruses and linked them to vessel locations from the marine Automated Information System. This yielded 206 vessel-exposed walrus telemetryPacific Walrus Behavior Data and Associated Chukchi Sea Ice Observations and Projections for use with Bioenergetics Models to Forecast Walrus Body Condition
This data release comprises 3 datasets used to develop forecasts of autumn body condition for adult female Pacific walruses in the Chukchi Sea during mid and late century time periods. The activity dataset contains daily telemetry records for 218 adult female walruses tracked for periods of 7 to 104 days during 2008-2014, in the Chukchi Sea. Records include the number of hours the walrus was in - Publications
Estimating Pacific walrus abundance and survival with multievent mark-recapture models
Arctic marine ecosystems are undergoing rapid physical and biological change associated with climate warming and loss of sea ice. Sea ice loss will impact many species through altered spatial and temporal availability of resources. In the Bering and Chukchi Seas, the Pacific walrus Odobenus rosmarus divergens is one species that could be impacted by rapid environmental change, and thus, populationRestoration of Gavia immer (common loon) in Minnesota—2021 annual report
The Deepwater Horizon oil spill caused extensive injury to natural resources in the Gulf of Mexico, and Gavia immer (common loon) were negatively affected from the spill. The Open Ocean Trustee Implementation Group funded the project Restoration of Common Loons in Minnesota to restore common loons lost to the spill. In 2020–21, priority lakes in an eight-county region in north-central Minnesota weWalrus haul-out and in water activity levels relative to sea ice availability in the Chukchi Sea
An animal’s energetic costs are dependent on the amount of time it allocates to various behavioral activities. For Arctic pinnipeds, the time allocated to active and resting behaviors could change with future reductions in sea ice cover and longer periods of open water. The Pacific walrus (Odobenus rosmarus divergens) is a large Arctic pinniped that rests on sea ice or land between foraging tripsHow will predicted land-use change affect waterfowl spring stopover ecology? Inferences from an individual-based model
Habitat loss, habitat fragmentation, overexploitation and climate change pose familiar and new challenges to conserving natural populations throughout the world. One approach conservation planners may use to evaluate the effects of these challenges on wildlife populations is scenario planning.We developed an individual-based model to evaluate the effects of future land use and land cover changes oSpace use of a dominant Arctic vertebrate: Effects of prey, sea ice, and land on Pacific walrus resource selection
Sea ice dominates marine ecosystems in the Arctic, and recent reductions in sea ice may alter food webs throughout the region. Sea ice loss may also stress Pacific walruses (Odobenus rosmarus divergens), which feed on benthic macroinvertebrates in the Bering and Chukchi seas. However, no studies have examined the effects of sea ice on foraging Pacific walrus space use patterns. We tested a seriesAn evaluation of behavior inferences from Bayesian state-space models: A case study with the Pacific walrus
State-space models offer researchers an objective approach to modeling complex animal location data sets, and state-space model behavior classifications are often assumed to have a link to animal behavior. In this study, we evaluated the behavioral classification accuracy of a Bayesian state-space model in Pacific walruses using Argos satellite tags with sensors to detect animal behavior in real t
*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