James L Bodkin (Former Employee)
Science and Products
Filter Total Items: 141
Status and Trends of Sea Otter Populations in Southeast Alaska, 1969-2003 Status and Trends of Sea Otter Populations in Southeast Alaska, 1969-2003
Aerial surveys of all known sea otter (Enhydra lutris) habitat in Southeast Alaska (SE AK) in 2002-2003 indicated a population size of 8,949 otters [Standard Error (SE) = 899] at an average density of 0.92 otters per square kilometer. These findings on sea otter distribution and abundance were compared to results from several previous surveys. Sea otters have expanded their range beyond...
Authors
George G. Esslinger, James L. Bodkin
Otters, Marine Otters, Marine
The otters (Mustelidae; Lutrinae) provide an exceptional perspective into the evolution of marine living by mammals. Most extant marine mammals (e.g. the cetaceans, pinnipeds, and sirenians) have been so highly modified by long periods of selection for life in the sea that they bear little resemblance to their terrestrial ancestors. Marine otters, in contrast, are more recent expatriates...
Authors
James A. Estes, James L. Bodkin, M. Ben-David
Phenotypic plasticity in age at first reproduction of female northern sea otters (Enhydra lutris kenyoni) Phenotypic plasticity in age at first reproduction of female northern sea otters (Enhydra lutris kenyoni)
Life-history theory predicts that within a species, reproduction and survival rates will differ among populations that differ in resource availability or predation rates through phenotypic plasticity. When populations are near carrying capacity (K) or when they are declining due to reduced prey resources, the average age at 1st reproduction (average AFR) is predicted to be older than in...
Authors
Vanessa R. von Biela, V.A. Gill, James L. Bodkin, Jennifer M. Burns
Activity budgets derived from time-depth recorders in a diving mammal Activity 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...
Authors
James L. Bodkin, Daniel H. Monson, George G. Esslinger
Strategies for survival: Marine mammals Strategies for survival: Marine mammals
No abstract available.
Authors
Sara J. Iverson, Alan M. Springer, James L. Bodkin
Marine mammal populations Marine mammal populations
No abstract available.
Authors
Alan M. Springer, Sara J. Iverson, James L. Bodkin
Strategies for survival: Stellar sea lions, harbor seals and sea otters Chapter 4.9 Strategies for survival: Stellar sea lions, harbor seals and sea otters Chapter 4.9
No abstract available.
Authors
Alan M. Springer, Sara J. Iverson, James L. Bodkin
Spatial and temporal variation in sea otter demography Spatial 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...
Authors
M. Tim Tinker, Daniel F. Doak, James A. Estes, Brian B. Hatfield, Michelle M. Steadler, James L. Bodkin
Patterns of growth and body condition in sea otters from the Aleutian archipelago before and after the recent population decline Patterns 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...
Authors
K.L. Laidre, J. A. Estes, M. T. Tinker, James L. Bodkin, Daniel H. Monson, K. Schneider
Foraging ecology Foraging 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...
Authors
M. Tim Tinker, James A. Estes, Michelle Staedler, James L. Bodkin
Verification of sex from harvested sea otters using DNA testing Verification 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
Authors
Kim T. Scribner, Ben A. Green, Carol Gorbics, James L. Bodkin
Science and Products
Filter Total Items: 141
Status and Trends of Sea Otter Populations in Southeast Alaska, 1969-2003 Status and Trends of Sea Otter Populations in Southeast Alaska, 1969-2003
Aerial surveys of all known sea otter (Enhydra lutris) habitat in Southeast Alaska (SE AK) in 2002-2003 indicated a population size of 8,949 otters [Standard Error (SE) = 899] at an average density of 0.92 otters per square kilometer. These findings on sea otter distribution and abundance were compared to results from several previous surveys. Sea otters have expanded their range beyond...
Authors
George G. Esslinger, James L. Bodkin
Otters, Marine Otters, Marine
The otters (Mustelidae; Lutrinae) provide an exceptional perspective into the evolution of marine living by mammals. Most extant marine mammals (e.g. the cetaceans, pinnipeds, and sirenians) have been so highly modified by long periods of selection for life in the sea that they bear little resemblance to their terrestrial ancestors. Marine otters, in contrast, are more recent expatriates...
Authors
James A. Estes, James L. Bodkin, M. Ben-David
Phenotypic plasticity in age at first reproduction of female northern sea otters (Enhydra lutris kenyoni) Phenotypic plasticity in age at first reproduction of female northern sea otters (Enhydra lutris kenyoni)
Life-history theory predicts that within a species, reproduction and survival rates will differ among populations that differ in resource availability or predation rates through phenotypic plasticity. When populations are near carrying capacity (K) or when they are declining due to reduced prey resources, the average age at 1st reproduction (average AFR) is predicted to be older than in...
Authors
Vanessa R. von Biela, V.A. Gill, James L. Bodkin, Jennifer M. Burns
Activity budgets derived from time-depth recorders in a diving mammal Activity 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...
Authors
James L. Bodkin, Daniel H. Monson, George G. Esslinger
Strategies for survival: Marine mammals Strategies for survival: Marine mammals
No abstract available.
Authors
Sara J. Iverson, Alan M. Springer, James L. Bodkin
Marine mammal populations Marine mammal populations
No abstract available.
Authors
Alan M. Springer, Sara J. Iverson, James L. Bodkin
Strategies for survival: Stellar sea lions, harbor seals and sea otters Chapter 4.9 Strategies for survival: Stellar sea lions, harbor seals and sea otters Chapter 4.9
No abstract available.
Authors
Alan M. Springer, Sara J. Iverson, James L. Bodkin
Spatial and temporal variation in sea otter demography Spatial 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...
Authors
M. Tim Tinker, Daniel F. Doak, James A. Estes, Brian B. Hatfield, Michelle M. Steadler, James L. Bodkin
Patterns of growth and body condition in sea otters from the Aleutian archipelago before and after the recent population decline Patterns 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...
Authors
K.L. Laidre, J. A. Estes, M. T. Tinker, James L. Bodkin, Daniel H. Monson, K. Schneider
Foraging ecology Foraging 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...
Authors
M. Tim Tinker, James A. Estes, Michelle Staedler, James L. Bodkin
Verification of sex from harvested sea otters using DNA testing Verification 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
Authors
Kim T. Scribner, Ben A. Green, Carol Gorbics, James L. Bodkin
*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