James L Bodkin
Population biology and ecology of marine mammals, population estimation, predator/prey relations, carnivora, coastal marine ecology, marine conservation.
Professional Experience
2013 - Present Research Wildlife Biologist Emeritus, USGS, Alaska Science Center, Anchorage, Alaska
1990 - 2013 Research Wildlife Biologist, USGS, Alaska Science Center, Anchorage, Alaska
1989 - 1990 Wildlife Biologist, U.S. Fish & Wildlife Service, Koyukuk Wildlife Refuge, Galena, AK
1986 - 1989 Fish and Wildlife Biologist, National Ecology Research Center, Santa Cruz, CA
Education and Certifications
M.S. 1986 California Polytechnical University, San Luis Obispo, CA Biology
B.S. 1975 California State University, Long Beach, CA Wildlife Biology
Affiliations and Memberships*
Society for Conservation Biology
American Society of Mammalogy
Society for Marine Mammalogy
The Wildlife Society
Science and Products
Strategies for survival: Stellar sea lions, harbor seals and sea otters Chapter 4.9
Activity budgets derived from time-depth recorders in a diving mammal
Spatial and temporal variation in sea otter demography
Foraging ecology
Patterns of growth and body condition in sea otters from the Aleutian archipelago before and after the recent population decline
Verification of sex from harvested sea otters using DNA testing
Studying sea otter foraging ecology: A review of some methodological approaches
Status of sea otter populations in southcentral and southeast Alaska, 2002-2003
Sea otter research methods and tools
Population demographics, survival, and reporduction: Alaska sea otter research
Sea otter studies in Glacier Bay National Park and Preserve
Science and Products
- Science
- Data
- Publications
Filter Total Items: 136
Strategies for survival: Stellar sea lions, harbor seals and sea otters Chapter 4.9
No abstract available.AuthorsAlan M. Springer, Sara J. Iverson, James L. BodkinActivity budgets derived from time-depth recorders in a diving mammal
We describe a method to convert continuously collected time–depth data from archival time–depth recorders (TDRs) into activity budgets for a benthic-foraging marine mammal. We used data from 14 TDRs to estimate activity-specific time budgets in sea otters (Enhydra lutris) residing near Cross Sound, southeast Alaska, USA. From the TDRs we constructed a continuous record of behavior for each individAuthorsJames L. Bodkin, Daniel H. Monson, George G. EsslingerSpatial and temporal variation in sea otter demography
1) Better information on historical and current population dynamics is central to understanding patterns of growth and decline in the California sea otter population. We developed a maximum likelihood-based analytical method to estimate historical age/sex specific vital rates as well as spatial and temporal variation in vital rates from longitudinal databases on population census numbers and the aAuthorsM. Tim Tinker, Daniel F. Doak, James A. Estes, Brian B. Hatfield, Michelle M. Steadler, James L. BodkinForaging ecology
Longitudinal foraging data collected from 60 sea otters implanted with VHF radio transmitters at two study sites in Central California over a three-year period demonstrated even greater individual dietary specialization than in previous studies, with only 54% dietary overlap between individuals and the population.Multivariate statistical analyses indicated that individual diets could be grouped inAuthorsM. Tim Tinker, James A. Estes, Michelle Staedler, James L. BodkinPatterns of growth and body condition in sea otters from the Aleutian archipelago before and after the recent population decline
1. Growth models for body mass and length were fitted to data collected from 1842 sea otters Enhydra lutris shot or live-captured throughout south-west Alaska between 1967 and 2004. Growth curves were constructed for each of two main year groups: 1967–71 when the population was at or near carrying capacity and 1992–97 when the population was in steep decline. Analyses of data collected from animalAuthorsK.L. Laidre, J. A. Estes, M. T. Tinker, James L. Bodkin, Daniel H. Monson, K. SchneiderVerification of sex from harvested sea otters using DNA testing
We used molecular genetic methods to determine the sex of 138 sea otters (Enhydra lutris) harvested from 3 regions of Alaska from 1994 to 1997, to assess the accuracy of post‐harvest field‐sexing. We also tested each of a series of factors associated with errors in field‐sexing of sea otters, including male or female bias, age‐class bias, regional bias, and bias associated with hunt characteristicAuthorsKim T. Scribner, Ben A. Green, Carol Gorbics, James L. BodkinStudying sea otter foraging ecology: A review of some methodological approaches
The study of foraging ecology plays a central role in our understanding of animal populations and natural communities, and can also provide information necessary for the effective conservation of rare or endangered species. Sea otter researchers are interested in foraging ecology for many different reasons, but for heuristic purposes we identify three general types of research questions: (1) questAuthorsM. T. Tinker, J. A. Estes, James L. Bodkin, M. M. Staedler, Daniel H. MonsonStatus of sea otter populations in southcentral and southeast Alaska, 2002-2003
During the years 2002-2004 estimated sea otter population sizes were calculated for Southeast Alaska, Prince William Sound, and the Kenai Peninsula and Cook Inlet regions of Alaska. Aerial surveys were conducted by a single observer from a float-equipped Bellanca Scout fixed-wing aircraft flying at 91 m altitude and 65 mph. The surveys followed protocols written by Bodkin and Udevitz (1999). The sAuthorsJames L. BodkinSea otter research methods and tools
Sea otters possess physical characteristics and life history attributes that provide both opportunity and constraint to their study. Because of their relatively limited diving ability they occur in nearshore marine habitats that are usually viewable from shore, allowing direct observation of most behaviors. Because sea otters live nearshore and forage on benthic invertebrates, foraging success andAuthorsJames L. BodkinPopulation demographics, survival, and reporduction: Alaska sea otter research
The fundamental force behind population change is the balance between age-specific survival and reproductive rates. Thus, understanding population demographics is crucial when trying to interpret trends in population change over time. For many species, demographic rates change as the population’s status (i.e., relative to prey resources) varies. Indices of body condition indicative of individual eAuthorsDaniel H. Monson, James L. Bodkin, D.F. Doak, James A. Estes, M. T. Tinker, D.B. SiniffSea otter studies in Glacier Bay National Park and Preserve
No abstract available.AuthorsJames L. Bodkin, Brenda E. Ballachey, Kimberly A. Kloecker, George G. Esslinger, Daniel H. Monson, H.A. Coletti, James A. Estes - News
*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