Julie Yee
Dr. Julie Yee is a Research Statistician with the Western Ecological Research Center (WERC).
Since 1997, she has used statistics and biometry for WERC to quantitatively analyze and interpret a variety of aspects of wildlife and plant population dynamics, such as recruitment, growth, survival, and wildlife movement. Her research has been applied to study the effects of renewable energy, contaminants, fire, and other influences on wildlife populations and ecosystems. She is currently a PI at the Santa Cruz field station where she supervises continued work on sea otter and nearshore research.
RESEARCH INTERESTS
- Frequentist and Bayesian statistical analysis
- Survival analysis
- Population dynamics
- Mark-recapture
- State-space modeling
- Integrated population modeling
- High performance computing
EDUCATION
- Ph.D., 1997, Statistics with Emphasis in Biostatistics, University of California, Davis.
- Dissertation Title: Asymptotic Approximations to Bayesian Posterior Distributions in Survival Problems with Incomplete Data
- M.S., 1993, Statistics, University of California, Davis
- B.S., 1991, Mathematics, California Institute of Technology
Science and Products
Filter Total Items: 52
Habitat features predict carrying capacity of a recovering marine carnivore
The recovery of large carnivore species from over‐exploitation can have socioecological effects; thus, reliable estimates of potential abundance and distribution represent a valuable tool for developing management objectives and recovery criteria. For sea otters (Enhydra lutris), as with many apex predators, equilibrium abundance is not constant across space but rather varies as a function of loca
Authors
M. Tim Tinker, Julie L. Yee, Kristin L. Laidre, Brian B. Hatfield, Michael D. Harris, Joseph A. Tomoleoni, Tom W. Bell, Emily Saarman, Lilian P. Carswell, A. Keith Miles
Feral burros and other influences on desert tortoise presence in the western Sonoran Desert
Across the globe, conflicting priorities exist in how land and resources are managed. In the American West, conflicts are common on public lands with historical mandates for multiple uses. We explored the impacts of multiple uses of land in a case study of Agassiz's Desert Tortoises (Gopherus agassizii), a federally threatened species, in the western Sonoran Desert. The tortoise has declined for m
Authors
Kristin H. Berry, Julie L. Yee, Lisa L. Lyren
Southern (California) sea otter population status and trends at San Nicolas Island, 2017–2020
The southern sea otter (Enhydra lutris nereis) population at San Nicolas Island, California, has been monitored annually since the translocation of 140 sea otters to the island was completed in 1990. Monitoring efforts have varied in frequency and type across years. In 2017, the U.S. Navy and the U.S. Fish and Wildlife Service initiated a sea otter monitoring and research plan to determine the eff
Authors
Julie L. Yee, Joseph A. Tomoleoni, Michael C. Kenner, Jessica Fujii, Gena B. Bentall, M. Tim Tinker, Brian B. Hatfield
The distribution of woody species in relation to climate and fire in Yosemite National Park, California, USA
BackgroundThe effects of climate on plant species ranges are well appreciated, but the effects of other processes, such as fire, on plant species distribution are less well understood. We used a dataset of 561 plots 0.1 ha in size located throughout Yosemite National Park, in the Sierra Nevada of California, USA, to determine the joint effects of fire and climate on woody plant species. We analyze
Authors
Jan W. van Wagtendonk, Peggy E Moore, Julie L. Yee, James A. Lutz
The catastrophic decline of tortoises at a fenced natural area
Agassiz’s desert tortoise (Gopherus agassizii), a threatened species of the southwestern United States, has severely declined to the point where 76% of populations in critical habitat (Tortoise Conservation Areas) are below viability. The potential for rapid recovery of wild populations is low because females require 12–20 years to reach reproductive maturity and produce few eggs annually. We repo
Authors
Kristin H. Berry, Julie L. Yee, Timothy A. Shields, Laura Stockton
Good prospects: High-resolution telemetry data suggests novel brood-site selection behavior in waterfowl
Breeding success should increase with prior knowledge of the surrounding environment, which is dependent upon an animal’s ability to evaluate habitat. Prospecting for nesting locations and migratory stop-over sites are well-established behaviors among bird species. We assessed whether ducks in Suisun Marsh, California, USA, a brackish marsh, prospect for suitable wetlands in the week prior to broo
Authors
Michael L. Casazza, Fiona McDuie, Austen Lorenz, David A. Keiter, Julie L. Yee, Cory T. Overton, Sarah H. Peterson, Cliff L. Feldheim, Joshua T. Ackerman
Assessing population-level consequences of anthropogenic stressors for terrestrial wildlife
Human activity influences wildlife. However, the ecological and conservation significances of these influences are difficult to predict and depend on their population‐level consequences. This difficulty arises partly because of information gaps, and partly because the data on stressors are usually collected in a count‐based manner (e.g., number of dead animals) that is difficult to translate into
Authors
Todd E. Katzner, Melissa A. Braham, Tara Conkling, James E. Diffendorfer, Adam E. Duerr, Scott R. Loss, David M. Nelson, Hannah B. Vander Zanden, Julie L. Yee
An uncertain future for a population of desert tortoises experiencing human impacts
We evaluated the status of a population of Mojave Desert Tortoises (Gopherus agassizii), a threatened species, in the El Paso Mountains of the northwestern Mojave Desert in California, USA. The study area lies north of and adjacent to a designated critical habitat unit for the species, is adjacent to a state park, and is a short distance from the Desert Tortoise Research Natural Area. We randomly
Authors
Kristin H. Berry, Julie L. Yee, Lisa L. Lyren, Jeremy S Mack
Trends in mammalian predator control trapping events intended to protect ground-nesting, endangered birds at Haleakalā National Park, Hawaiʻi: 2000–14
Predation and habitat degradation by non-native species are principal terrestrial threats to the federally endangered Hawaiian Petrel (ʻuaʻu, Pterodroma sandwichensis) and Hawaiian Goose (nēnē, Branta sandvicensis) within Haleakalā National Park (HALE), Maui, Hawaiʻi. Since 1981, HALE has maintained a network of live traps to control invasive mammalian predators and protect these endangered birds.
Authors
Emily C. Kelsey, Josh Adams, Max F. Czapanskiy, Jonathan J. Felis, Julie L. Yee, Raina L. Kaholoaa, Cathleen Natividad Bailey
Wind energy: An ecological challenge
No abstract available.
Authors
Todd E. Katzner, David M. Nelson, Jay E. Diffendorfer, Adam E. Duerr, Caitlin J. Campbell, Douglas Leslie, Hanna B. Vander Zanden, Julie L. Yee, Maitreyi Sur, Manuela M. Huso, Melissa A. Braham, Michael L. Morrison, Scott R. Loss, Sharon Poessel, Tara Conkling, Tricia A. Miller
California sea otter (Enhydra lutris nereis) census results, spring 2019
The 2019 census of southern sea otters (Enhydra lutris nereis), also known as California sea otters, was conducted from early May to early July along the mainland coast of central California and in April at San Nicolas Island in southern California. The range-wide index, defined as the 3-year average of combined counts from the mainland range and San Nicolas Island, was 2,962, a decrease of 166 se
Authors
Brian B. Hatfield, Julie L. Yee, Michael C. Kenner, Joseph A. Tomoleoni
Which trees die during drought? The key role of insect host-tree selection
1. During drought, the tree subpopulations (such as size or vigor classes) that suffer disproportionate mortality can be conceptually arrayed along a continuum defined by the actions of biotic agents, particularly insects. At one extreme, stress dominates: insects are absent or simply kill the most physiologically stressed trees. At the opposite extreme, host selection dominates: outbreaking
Authors
Nathan L. Stephenson, Adrian J. Das, Nicholas J. Ampersee, Beverly M Bulaon, Julie L. Yee
Science and Products
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Filter Total Items: 52
Habitat features predict carrying capacity of a recovering marine carnivore
The recovery of large carnivore species from over‐exploitation can have socioecological effects; thus, reliable estimates of potential abundance and distribution represent a valuable tool for developing management objectives and recovery criteria. For sea otters (Enhydra lutris), as with many apex predators, equilibrium abundance is not constant across space but rather varies as a function of locaAuthorsM. Tim Tinker, Julie L. Yee, Kristin L. Laidre, Brian B. Hatfield, Michael D. Harris, Joseph A. Tomoleoni, Tom W. Bell, Emily Saarman, Lilian P. Carswell, A. Keith MilesFeral burros and other influences on desert tortoise presence in the western Sonoran Desert
Across the globe, conflicting priorities exist in how land and resources are managed. In the American West, conflicts are common on public lands with historical mandates for multiple uses. We explored the impacts of multiple uses of land in a case study of Agassiz's Desert Tortoises (Gopherus agassizii), a federally threatened species, in the western Sonoran Desert. The tortoise has declined for mAuthorsKristin H. Berry, Julie L. Yee, Lisa L. LyrenSouthern (California) sea otter population status and trends at San Nicolas Island, 2017–2020
The southern sea otter (Enhydra lutris nereis) population at San Nicolas Island, California, has been monitored annually since the translocation of 140 sea otters to the island was completed in 1990. Monitoring efforts have varied in frequency and type across years. In 2017, the U.S. Navy and the U.S. Fish and Wildlife Service initiated a sea otter monitoring and research plan to determine the effAuthorsJulie L. Yee, Joseph A. Tomoleoni, Michael C. Kenner, Jessica Fujii, Gena B. Bentall, M. Tim Tinker, Brian B. HatfieldThe distribution of woody species in relation to climate and fire in Yosemite National Park, California, USA
BackgroundThe effects of climate on plant species ranges are well appreciated, but the effects of other processes, such as fire, on plant species distribution are less well understood. We used a dataset of 561 plots 0.1 ha in size located throughout Yosemite National Park, in the Sierra Nevada of California, USA, to determine the joint effects of fire and climate on woody plant species. We analyzeAuthorsJan W. van Wagtendonk, Peggy E Moore, Julie L. Yee, James A. LutzThe catastrophic decline of tortoises at a fenced natural area
Agassiz’s desert tortoise (Gopherus agassizii), a threatened species of the southwestern United States, has severely declined to the point where 76% of populations in critical habitat (Tortoise Conservation Areas) are below viability. The potential for rapid recovery of wild populations is low because females require 12–20 years to reach reproductive maturity and produce few eggs annually. We repoAuthorsKristin H. Berry, Julie L. Yee, Timothy A. Shields, Laura StocktonGood prospects: High-resolution telemetry data suggests novel brood-site selection behavior in waterfowl
Breeding success should increase with prior knowledge of the surrounding environment, which is dependent upon an animal’s ability to evaluate habitat. Prospecting for nesting locations and migratory stop-over sites are well-established behaviors among bird species. We assessed whether ducks in Suisun Marsh, California, USA, a brackish marsh, prospect for suitable wetlands in the week prior to brooAuthorsMichael L. Casazza, Fiona McDuie, Austen Lorenz, David A. Keiter, Julie L. Yee, Cory T. Overton, Sarah H. Peterson, Cliff L. Feldheim, Joshua T. AckermanAssessing population-level consequences of anthropogenic stressors for terrestrial wildlife
Human activity influences wildlife. However, the ecological and conservation significances of these influences are difficult to predict and depend on their population‐level consequences. This difficulty arises partly because of information gaps, and partly because the data on stressors are usually collected in a count‐based manner (e.g., number of dead animals) that is difficult to translate intoAuthorsTodd E. Katzner, Melissa A. Braham, Tara Conkling, James E. Diffendorfer, Adam E. Duerr, Scott R. Loss, David M. Nelson, Hannah B. Vander Zanden, Julie L. YeeAn uncertain future for a population of desert tortoises experiencing human impacts
We evaluated the status of a population of Mojave Desert Tortoises (Gopherus agassizii), a threatened species, in the El Paso Mountains of the northwestern Mojave Desert in California, USA. The study area lies north of and adjacent to a designated critical habitat unit for the species, is adjacent to a state park, and is a short distance from the Desert Tortoise Research Natural Area. We randomlyAuthorsKristin H. Berry, Julie L. Yee, Lisa L. Lyren, Jeremy S MackTrends in mammalian predator control trapping events intended to protect ground-nesting, endangered birds at Haleakalā National Park, Hawaiʻi: 2000–14
Predation and habitat degradation by non-native species are principal terrestrial threats to the federally endangered Hawaiian Petrel (ʻuaʻu, Pterodroma sandwichensis) and Hawaiian Goose (nēnē, Branta sandvicensis) within Haleakalā National Park (HALE), Maui, Hawaiʻi. Since 1981, HALE has maintained a network of live traps to control invasive mammalian predators and protect these endangered birds.AuthorsEmily C. Kelsey, Josh Adams, Max F. Czapanskiy, Jonathan J. Felis, Julie L. Yee, Raina L. Kaholoaa, Cathleen Natividad BaileyWind energy: An ecological challenge
No abstract available.AuthorsTodd E. Katzner, David M. Nelson, Jay E. Diffendorfer, Adam E. Duerr, Caitlin J. Campbell, Douglas Leslie, Hanna B. Vander Zanden, Julie L. Yee, Maitreyi Sur, Manuela M. Huso, Melissa A. Braham, Michael L. Morrison, Scott R. Loss, Sharon Poessel, Tara Conkling, Tricia A. MillerCalifornia sea otter (Enhydra lutris nereis) census results, spring 2019
The 2019 census of southern sea otters (Enhydra lutris nereis), also known as California sea otters, was conducted from early May to early July along the mainland coast of central California and in April at San Nicolas Island in southern California. The range-wide index, defined as the 3-year average of combined counts from the mainland range and San Nicolas Island, was 2,962, a decrease of 166 seAuthorsBrian B. Hatfield, Julie L. Yee, Michael C. Kenner, Joseph A. TomoleoniWhich trees die during drought? The key role of insect host-tree selection
1. During drought, the tree subpopulations (such as size or vigor classes) that suffer disproportionate mortality can be conceptually arrayed along a continuum defined by the actions of biotic agents, particularly insects. At one extreme, stress dominates: insects are absent or simply kill the most physiologically stressed trees. At the opposite extreme, host selection dominates: outbreakingAuthorsNathan L. Stephenson, Adrian J. Das, Nicholas J. Ampersee, Beverly M Bulaon, Julie L. Yee - News