Cory Overton
Cory Overton is a wildlife biologist at the Western Ecological Research Center.
Science and Products
AIMS for Wildlife
We are building a 21st century wildlife monitoring system to inform resource management of the impacts of drought, wildfire, land use, climate change, and other landscape level stressors. The Automated Interactive Monitoring System (AIMS) for Wildlife will provide an actionable data stream by combining enormous quantities of wildlife movement data with environmental data and delivering it to...
Waterbird Ecology and Movement in the Saline Lakes
How do changing conditions in the terminal lakes of the Great Basin effect the migratory birds that depend on them? USGS scientists investigate bird movement and habitat use to find out.
Goose Population Dynamics in the California Central Valley and Pacific Flyway
USGS scientists and partners are studying how growing goose populations in the California Central Valley wintering areas are affecting ducks and other waterfowl.
Webinar: Linking Remote Sensing and Bird Behavior Data to Understand the Impacts of Drought on Waterfowl
View this webinar to learn how scientists are exploring the impacts of drought on waterfowl.
The Impact of Drought on Waterbirds and Their Wetland Habitats in California’s Central Valley
California’s Central Valley is a nexus for water resources in the state, draining the Sacramento and San Joaquin River watersheds. Urban centers, agricultural operations, and the environment all compete for limited water, and demand is expected to only increase as the population grows and agriculture intensifies. At the same time, the water supply is projected to decrease as temperatures rise, pre
Effects of Sea-Level Rise and Extreme Storms on California Coastal Habitats: Part 1
In California, the near-shore area where the ocean meets the land is a highly productive yet sensitive region that supports a wealth of wildlife, including several native bird species. These saltmarshes, mudflats, and shallow bays are not only critical for wildlife, but they also provide economic and recreational benefits to local communities. Today, sea-level rise, more frequent and stronger stor
Fate of Endangered Species in San Francisco Bay Tidal Marshes with Sea-Level Rise
The San Francisco Bay estuary contains the largest remaining expanse of tidal salt marshes in the western U.S. These marshes are home to a variety of federal and state protected species, such as the California clapper rail, California black rail, and the salt marsh harvest mouse. The estuary is also located on the Pacific Flyway, and is an important site for migrating and wintering birds. As clima
Filter Total Items: 19
Timing of Occurrence of Waterfowl in U.S. Counties and Canadian Counties, Boroughs, Census Districts, and Other Populated Area Designations with Modeled Exposure Status to Highly Pathogenic Avian Influenza Virus in 2021-2022
This data provides county level occurrence information for all individuals used in modelling potential exposure and spread of highly pathogenic avian influenza (HPAIv) from the 2021-2022 North American outbreak. The data set contains individual identifiers and taxa information, an indicator of exposure, exposure status (Susceptible, Exposed by HPAIv detection in the county, or Exposed by secondary
Movement Data for Migrating Geese Over the Northeast Pacific Ocean, 2018-2021
This dataset consists of one table with a record (row) for each goose location and columns containing location information and covariates. The dataset was used in an analysis of altitude selection and flight propensity in an accompanying paper (Weiser et al. 2024) and is being provided here to allow replication of that analysis. Goose locations (latitude, longitude, and altitude) were collected wi
Data describing habitat use and availability for wild waterfowl in California, USA
These data describe the overlap of wild waterfowl and domestic poultry operations in California, USA. These data support a paired USGS publication.
Movements, Used Habitats, and Available Habitats Identified using Step Selection Processes for Four Species of Waterfowl in California's Central Valley, 2016-2022
Step selection functions use animal movement patterns to estimate habitats available at each step along a movement track. These data were generated from four species of waterfowl (Anser albifrons [greater white-fronted goose], Anser caerulescens caerulescens [lesser snow goose], Anas platyrhynchos [mallard], Anas acuta [northern pintail]) using the Central Valley of California 2016 to 2022 that we
Waterfowl GPS Observations in North America from 2015 to 2023 for Custom Wildlife Report Example for Sacramento National Wildlife Refuge
To effectively manage species and habitats at multiple scales, land managers require rapid information on wildlife use of managed areas and responses to landscape conditions and management actions. Global positioning system (GPS) tracking studies of wildlife are particularly informative to species ecology, habitat use, and conservation. Combining GPS data with administrative data, would more compr
Bibliography of hydrological and ecological research in the Great Basin terminal lakes, USA
This database contains literature citations and associated abstracts pertaining to the ecology and hydrology of terminal lakes in the Great Basin region of the western United States. This is not meant to be an exhaustive list, nor did we perform a systematic meta-analysis; rather, literature records were included based on topical relevance.
Data describing infection status and movement ecology of North American waterfowl
These data, which support a USGS authored manuscript, describe how active and previous previous infection with avian influenza impacts the movement ecology of several wild waterfowl species that overwinter in California. Results varied by species and demonstrate that the relationships between avian influenza infection and wild bird movements are context- and species-dependent.
Hourly GPS Locations, Associated Habitat Condition, and Annotated Life History State for Training Machine Learned Models of Waterfowl Daily Activity
These data represent an annotated training data for machine learned life history classification of the daily activity of dabbling ducks (f. Anatidae sf. Anatinae) using hourly GPS data. Each row of data represents a single GPS location for one of 5 species of dabbling duck. Note: the machine learned model was developed to be general across sf. Anatinae and does not include specific reference to th
Data measuring avian influenza infection, mercury concentration, and body condition in wild waterfowl
These data represent mercury contamination, influenza infection, and body condition in 11 species of dabbling and diving ducks in the Pacific Flyway. These data support a USGS lead scientific publication.
Selenium concentrations in Yuma Ridgway's Rails occupying managed and unmanaged emergent marshes at the Salton Sea
Yuma Ridgway's rail (Rallus obsoletus yumanensis, hereafter, "rail" are an endangered species for which patches of emergent marsh within the Salton Sea watershed comprise a substantial portion of habitat for the species' disjointed range in the southwestern United States. These areas of emergent marsh include: 1) marshes managed by federal (particularly the U.S. Fish and Wildlife Service's Sonny B
Yuma Ridgway's Rail (Rallus obsoletus yumanensis) Population Surveys, Rail Movement, and Potential Habitat at the Salton Sea of California
Data were obtained as part of a project assessing risk to the federal and California listed endangered Yuma Ridgway's rail (Rallus obsoletus yumanensis) populations resulting from selenium contaminated agricultural runoff and to inform habitat restoration and management decisions. Four data sets were produced and used to analyze patterns of Yuma Ridgway's rail (Rallus obsoletus yumanensis, renamed
Suisun Tidal Marsh Duck Use Dataset
Location data with corresponding habitat class (managed vs tidal marsh) and habitat type (permanent pond, seasonal pond, channel, or marshland) for waterfowl utilizing the Suisun Marsh region of California with species, sex, season and date information.
These data support the following publication:
Casazza, M.L., McDuie, F., Jones, S., Lorenz, A.A., Overton, C.T., Yee, J., Feldheim, C.L., Acke
Filter Total Items: 51
Mitigating risk: Predicting H5N1 avian influenza spread with an empirical model of bird movement
Understanding timing and distribution of virus spread is critical to global commercial and wildlife biosecurity management. A highly pathogenic avian influenza virus (HPAIv) global panzootic, affecting ~600 bird and mammal species globally and over 83 million birds across North America (Dec 2023), poses a serious global threat to animals and public health. We combined a large, long-term waterfowl
Authors
Fiona McDuie, Cory T. Overton, Austen Lorenz, Elliott Matchett, Andrea Mott, Desmond Alexander Mackell, Josh T. Ackerman, Susan E. W. De La Cruz, Vijay P. Patil, Diann Prosser, John Y. Takekawa, Dennis L. Orthmeyer, Maurice E. Pitesky, Samuel L. Díaz-Muñoz, Brock M. Riggs, Joseph Gendreau, Eric T. Reed, Mark J. Petrie, Chris K. Williams, Jeffrey J. Buler, Matthew J. Hardy, Brian S. Ladman, Pierre Legagneux, Joël Bêty, Philippe J. Thomas, Jean Rodrigue, Josée Lefebvre, Michael L. Casazza
Potential use of poultry farms by wild waterfowl in California's Central Valley varies across space, times of day, and species: implications for influenza transmission risk
Interactions between wildlife and livestock can lead to cross-species disease transmission, which incurs economic costs and threatens wildlife conservation. Wild waterfowl are natural hosts of avian influenza viruses (AIVs), are often abundant near poultry farms, and have been linked to outbreaks of AIVs in poultry. Interspecific and seasonal variation in waterfowl movement and habitat use means t
Authors
Claire S. Teitelbaum, Michael L. Casazza, Cory T. Overton, Jeffery D. Sullivan, Elliott Matchett, Fiona McDuie, Austen Lorenz, Josh T. Ackerman, Susan E. W. De La Cruz, Diann Prosser
Geese migrating over the Pacific Ocean select altitudes coinciding with offshore wind turbine blades
Renewable energy facilities are a key part of mitigating climate change, but can pose threats to wild birds and bats, most often through collisions with infrastructure. Understanding collision risk and the factors affecting it can help minimize impacts on wild populations. For wind turbines, flight altitude is a major factor influencing collision risk, and altitude-selection analyses can evaluate
Authors
Emily L. Weiser, Cory T. Overton, David C. Douglas, Michael L. Casazza, Paul L. Flint
Integrated science strategy for assessing and monitoring water availability and migratory birds for terminal lakes across the Great Basin, United States
Executive SummaryIn 2022, the U.S. Geological Survey (USGS) established the Saline Lake Ecosystems Integrated Water Availability Assessment (IWAAs) to monitor and assess the hydrology of terminal lakes in the Great Basin and the migratory birds and other wildlife dependent on those habitats. Scientists from across the USGS (with specialties in water quantity, water quality, limnology, avian biolog
Authors
Rebecca J. Frus, Cameron L. Aldridge, Michael L. Casazza, Collin A. Eagles-Smith, Garth Herring, Scott A. Hynek, Daniel K. Jones, Susan K Kemp, Thomas M. Marston, Christopher M. Morris, Ramon C. Naranjo, Cee Nell, David R. O'Leary, Cory T. Overton, Bryce A. Pulver, Brian E. Reichert, Christine A. Rumsey, Rudy Schuster, Cassandra D. Smith
Movement behavior, habitat selection, and functional responses to habitat availability among four species of wintering waterfowl in California
Habitat selection analyses provide a window into the perceived value of habitats by animals and how those perceptions compare with other animals, change across time, or change in relation to availability (termed functional responses). Habitat selection analysis and functional responses can be used to develop strategies to avoid habitat limitations, guide habitat management, and set attainable cons
Authors
Cory T. Overton, Michael L. Casazza
AIMS for wildlife: Developing an automated interactive monitoring system to integrate real-time movement and environmental data for true adaptive management
To effectively manage species and habitats at multiple scales, population and land managers require rapid information on wildlife use of managed areas and responses to landscape conditions and management actions. GPS tracking studies of wildlife are particularly informative to species ecology, habitat use, and conservation. Combining GPS data with administrative data and a diverse suite of remotel
Authors
Michael L. Casazza, Austen Lorenz, Cory T. Overton, Elliott L. Matchett, Andrea Lynn Mott, Desmond Alexander Mackell, Fiona McDuie
Waterfowl recently infected with low pathogenic avian influenza exhibit reduced local movement and delayed migration
Understanding relationships between infection and wildlife movement patterns is important for predicting pathogen spread, especially for multispecies pathogens and those that can spread to humans and domestic animals, such as avian influenza viruses (AIVs). Although infection with low pathogenic AIVs is generally considered asymptomatic in wild birds, prior work has shown that influenza-infected b
Authors
Claire S. Teitelbaum, Michael L. Casazza, Fiona McDuie, Susan E. W. De La Cruz, Cory T. Overton, Laurie Anne Hall, Elliott Matchett, Josh T. Ackerman, Jeffery D. Sullivan, Andrew M. Ramey, Diann Prosser
Postbreeding movements and molting ecology of female gadwalls and mallards
The wing molt is an important annual life-history event that occurs in waterfowl and molt site selection can play an important role in determining survival. We tracked postbreeding movements of gadwall (Mareca strepera) and mallard (Anas platyrhynchos) females that bred in the Suisun Marsh (Suisun) of California, USA, to determine molt site selection and wing molt chronology. We attached backpack
Authors
Jeffrey D Kohl, Michael L. Casazza, Cory T. Overton, Mark P. Herzog, Josh T. Ackerman, Cliff L. Feldheim, John M. Eadie
Avian influenza antibody prevalence increases with mercury contamination in wild waterfowl
Environmental contamination is widespread and can negatively impact wildlife health. Some contaminants, including heavy metals, have immunosuppressive effects, but prior studies have rarely measured contamination and disease simultaneously, which limits our understanding of how contaminants and pathogens interact to influence wildlife health. Here, we measured mercury concentrations, influenza inf
Authors
Claire Stewart Teitelbaum, Josh T. Ackerman, Mason A. Hill, Jaqueline M. Satter, Michael L. Casazza, Susan E. W. De La Cruz, Walter M. Boyce, Evan James Buck, John M. Eadie, Mark P. Herzog, Elliott Matchett, Cory T. Overton, Sarah H. Peterson, Magdalena Plancarte, Andrew M. Ramey, Jeffery D. Sullivan, Diann Prosser
Yuma Ridgway’s rail selenium exposure and occupancy within managed and unmanaged emergent marshes at the Salton Sea
Yuma Ridgway’s rail (Rallus obsoletus yumanensis, hereafter, rail) is an endangered species for which patches of emergent marsh within the Salton Sea watershed comprise a substantial part of habitat for the species’ disjointed range in the southwestern United States. These areas of emergent marsh include (1) marshes managed by federal (particularly the U.S. Fish and Wildlife Service’s Sonny Bono S
Authors
Mark A. Ricca, Cory T. Overton, Thomas W. Anderson, Angela Merritt, Eamon Harrity, Elliott Matchett, Michael L. Casazza
Machine learned daily life history classification using low frequency tracking data and automated modelling pipelines: Application to North American waterfowl
BackgroundIdentifying animal behaviors, life history states, and movement patterns is a prerequisite for many animal behavior analyses and effective management of wildlife and habitats. Most approaches classify short-term movement patterns with high frequency location or accelerometry data. However, patterns reflecting life history across longer time scales can have greater relevance to species bi
Authors
Cory T. Overton, Michael L. Casazza, Joseph Bretz, Fiona McDuie, Elliott Matchett, Desmond Alexander Mackell, Austen Lorenz, Andrea Mott, Mark P. Herzog, Josh T. Ackerman
Pathways for avian influenza virus spread: GPS reveals wild waterfowl in commercial livestock facilities and connectivity with the natural wetland landscape
Zoonotic diseases are of considerable concern to the human population and viruses such as avian influenza (AIV) threaten food security, wildlife conservation and human health. Wild waterfowl and the natural wetlands they use are known AIV reservoirs, with birds capable of virus transmission to domestic poultry populations. While infection risk models have linked migration routes and AIV outbreaks,
Authors
Fiona McDuie, Elliott Matchett, Diann Prosser, John Y. Takekawa, Maurice E. Pitesky, Austen Lorenz, Madeline M McCuen, Cory T. Overton, Josh T. Ackerman, Susan E. W. De La Cruz, Michael L. Casazza
Science and Products
AIMS for Wildlife
We are building a 21st century wildlife monitoring system to inform resource management of the impacts of drought, wildfire, land use, climate change, and other landscape level stressors. The Automated Interactive Monitoring System (AIMS) for Wildlife will provide an actionable data stream by combining enormous quantities of wildlife movement data with environmental data and delivering it to...
Waterbird Ecology and Movement in the Saline Lakes
How do changing conditions in the terminal lakes of the Great Basin effect the migratory birds that depend on them? USGS scientists investigate bird movement and habitat use to find out.
Goose Population Dynamics in the California Central Valley and Pacific Flyway
USGS scientists and partners are studying how growing goose populations in the California Central Valley wintering areas are affecting ducks and other waterfowl.
Webinar: Linking Remote Sensing and Bird Behavior Data to Understand the Impacts of Drought on Waterfowl
View this webinar to learn how scientists are exploring the impacts of drought on waterfowl.
The Impact of Drought on Waterbirds and Their Wetland Habitats in California’s Central Valley
California’s Central Valley is a nexus for water resources in the state, draining the Sacramento and San Joaquin River watersheds. Urban centers, agricultural operations, and the environment all compete for limited water, and demand is expected to only increase as the population grows and agriculture intensifies. At the same time, the water supply is projected to decrease as temperatures rise, pre
Effects of Sea-Level Rise and Extreme Storms on California Coastal Habitats: Part 1
In California, the near-shore area where the ocean meets the land is a highly productive yet sensitive region that supports a wealth of wildlife, including several native bird species. These saltmarshes, mudflats, and shallow bays are not only critical for wildlife, but they also provide economic and recreational benefits to local communities. Today, sea-level rise, more frequent and stronger stor
Fate of Endangered Species in San Francisco Bay Tidal Marshes with Sea-Level Rise
The San Francisco Bay estuary contains the largest remaining expanse of tidal salt marshes in the western U.S. These marshes are home to a variety of federal and state protected species, such as the California clapper rail, California black rail, and the salt marsh harvest mouse. The estuary is also located on the Pacific Flyway, and is an important site for migrating and wintering birds. As clima
Filter Total Items: 19
Timing of Occurrence of Waterfowl in U.S. Counties and Canadian Counties, Boroughs, Census Districts, and Other Populated Area Designations with Modeled Exposure Status to Highly Pathogenic Avian Influenza Virus in 2021-2022
This data provides county level occurrence information for all individuals used in modelling potential exposure and spread of highly pathogenic avian influenza (HPAIv) from the 2021-2022 North American outbreak. The data set contains individual identifiers and taxa information, an indicator of exposure, exposure status (Susceptible, Exposed by HPAIv detection in the county, or Exposed by secondary
Movement Data for Migrating Geese Over the Northeast Pacific Ocean, 2018-2021
This dataset consists of one table with a record (row) for each goose location and columns containing location information and covariates. The dataset was used in an analysis of altitude selection and flight propensity in an accompanying paper (Weiser et al. 2024) and is being provided here to allow replication of that analysis. Goose locations (latitude, longitude, and altitude) were collected wi
Data describing habitat use and availability for wild waterfowl in California, USA
These data describe the overlap of wild waterfowl and domestic poultry operations in California, USA. These data support a paired USGS publication.
Movements, Used Habitats, and Available Habitats Identified using Step Selection Processes for Four Species of Waterfowl in California's Central Valley, 2016-2022
Step selection functions use animal movement patterns to estimate habitats available at each step along a movement track. These data were generated from four species of waterfowl (Anser albifrons [greater white-fronted goose], Anser caerulescens caerulescens [lesser snow goose], Anas platyrhynchos [mallard], Anas acuta [northern pintail]) using the Central Valley of California 2016 to 2022 that we
Waterfowl GPS Observations in North America from 2015 to 2023 for Custom Wildlife Report Example for Sacramento National Wildlife Refuge
To effectively manage species and habitats at multiple scales, land managers require rapid information on wildlife use of managed areas and responses to landscape conditions and management actions. Global positioning system (GPS) tracking studies of wildlife are particularly informative to species ecology, habitat use, and conservation. Combining GPS data with administrative data, would more compr
Bibliography of hydrological and ecological research in the Great Basin terminal lakes, USA
This database contains literature citations and associated abstracts pertaining to the ecology and hydrology of terminal lakes in the Great Basin region of the western United States. This is not meant to be an exhaustive list, nor did we perform a systematic meta-analysis; rather, literature records were included based on topical relevance.
Data describing infection status and movement ecology of North American waterfowl
These data, which support a USGS authored manuscript, describe how active and previous previous infection with avian influenza impacts the movement ecology of several wild waterfowl species that overwinter in California. Results varied by species and demonstrate that the relationships between avian influenza infection and wild bird movements are context- and species-dependent.
Hourly GPS Locations, Associated Habitat Condition, and Annotated Life History State for Training Machine Learned Models of Waterfowl Daily Activity
These data represent an annotated training data for machine learned life history classification of the daily activity of dabbling ducks (f. Anatidae sf. Anatinae) using hourly GPS data. Each row of data represents a single GPS location for one of 5 species of dabbling duck. Note: the machine learned model was developed to be general across sf. Anatinae and does not include specific reference to th
Data measuring avian influenza infection, mercury concentration, and body condition in wild waterfowl
These data represent mercury contamination, influenza infection, and body condition in 11 species of dabbling and diving ducks in the Pacific Flyway. These data support a USGS lead scientific publication.
Selenium concentrations in Yuma Ridgway's Rails occupying managed and unmanaged emergent marshes at the Salton Sea
Yuma Ridgway's rail (Rallus obsoletus yumanensis, hereafter, "rail" are an endangered species for which patches of emergent marsh within the Salton Sea watershed comprise a substantial portion of habitat for the species' disjointed range in the southwestern United States. These areas of emergent marsh include: 1) marshes managed by federal (particularly the U.S. Fish and Wildlife Service's Sonny B
Yuma Ridgway's Rail (Rallus obsoletus yumanensis) Population Surveys, Rail Movement, and Potential Habitat at the Salton Sea of California
Data were obtained as part of a project assessing risk to the federal and California listed endangered Yuma Ridgway's rail (Rallus obsoletus yumanensis) populations resulting from selenium contaminated agricultural runoff and to inform habitat restoration and management decisions. Four data sets were produced and used to analyze patterns of Yuma Ridgway's rail (Rallus obsoletus yumanensis, renamed
Suisun Tidal Marsh Duck Use Dataset
Location data with corresponding habitat class (managed vs tidal marsh) and habitat type (permanent pond, seasonal pond, channel, or marshland) for waterfowl utilizing the Suisun Marsh region of California with species, sex, season and date information.
These data support the following publication:
Casazza, M.L., McDuie, F., Jones, S., Lorenz, A.A., Overton, C.T., Yee, J., Feldheim, C.L., Acke
Filter Total Items: 51
Mitigating risk: Predicting H5N1 avian influenza spread with an empirical model of bird movement
Understanding timing and distribution of virus spread is critical to global commercial and wildlife biosecurity management. A highly pathogenic avian influenza virus (HPAIv) global panzootic, affecting ~600 bird and mammal species globally and over 83 million birds across North America (Dec 2023), poses a serious global threat to animals and public health. We combined a large, long-term waterfowl
Authors
Fiona McDuie, Cory T. Overton, Austen Lorenz, Elliott Matchett, Andrea Mott, Desmond Alexander Mackell, Josh T. Ackerman, Susan E. W. De La Cruz, Vijay P. Patil, Diann Prosser, John Y. Takekawa, Dennis L. Orthmeyer, Maurice E. Pitesky, Samuel L. Díaz-Muñoz, Brock M. Riggs, Joseph Gendreau, Eric T. Reed, Mark J. Petrie, Chris K. Williams, Jeffrey J. Buler, Matthew J. Hardy, Brian S. Ladman, Pierre Legagneux, Joël Bêty, Philippe J. Thomas, Jean Rodrigue, Josée Lefebvre, Michael L. Casazza
Potential use of poultry farms by wild waterfowl in California's Central Valley varies across space, times of day, and species: implications for influenza transmission risk
Interactions between wildlife and livestock can lead to cross-species disease transmission, which incurs economic costs and threatens wildlife conservation. Wild waterfowl are natural hosts of avian influenza viruses (AIVs), are often abundant near poultry farms, and have been linked to outbreaks of AIVs in poultry. Interspecific and seasonal variation in waterfowl movement and habitat use means t
Authors
Claire S. Teitelbaum, Michael L. Casazza, Cory T. Overton, Jeffery D. Sullivan, Elliott Matchett, Fiona McDuie, Austen Lorenz, Josh T. Ackerman, Susan E. W. De La Cruz, Diann Prosser
Geese migrating over the Pacific Ocean select altitudes coinciding with offshore wind turbine blades
Renewable energy facilities are a key part of mitigating climate change, but can pose threats to wild birds and bats, most often through collisions with infrastructure. Understanding collision risk and the factors affecting it can help minimize impacts on wild populations. For wind turbines, flight altitude is a major factor influencing collision risk, and altitude-selection analyses can evaluate
Authors
Emily L. Weiser, Cory T. Overton, David C. Douglas, Michael L. Casazza, Paul L. Flint
Integrated science strategy for assessing and monitoring water availability and migratory birds for terminal lakes across the Great Basin, United States
Executive SummaryIn 2022, the U.S. Geological Survey (USGS) established the Saline Lake Ecosystems Integrated Water Availability Assessment (IWAAs) to monitor and assess the hydrology of terminal lakes in the Great Basin and the migratory birds and other wildlife dependent on those habitats. Scientists from across the USGS (with specialties in water quantity, water quality, limnology, avian biolog
Authors
Rebecca J. Frus, Cameron L. Aldridge, Michael L. Casazza, Collin A. Eagles-Smith, Garth Herring, Scott A. Hynek, Daniel K. Jones, Susan K Kemp, Thomas M. Marston, Christopher M. Morris, Ramon C. Naranjo, Cee Nell, David R. O'Leary, Cory T. Overton, Bryce A. Pulver, Brian E. Reichert, Christine A. Rumsey, Rudy Schuster, Cassandra D. Smith
Movement behavior, habitat selection, and functional responses to habitat availability among four species of wintering waterfowl in California
Habitat selection analyses provide a window into the perceived value of habitats by animals and how those perceptions compare with other animals, change across time, or change in relation to availability (termed functional responses). Habitat selection analysis and functional responses can be used to develop strategies to avoid habitat limitations, guide habitat management, and set attainable cons
Authors
Cory T. Overton, Michael L. Casazza
AIMS for wildlife: Developing an automated interactive monitoring system to integrate real-time movement and environmental data for true adaptive management
To effectively manage species and habitats at multiple scales, population and land managers require rapid information on wildlife use of managed areas and responses to landscape conditions and management actions. GPS tracking studies of wildlife are particularly informative to species ecology, habitat use, and conservation. Combining GPS data with administrative data and a diverse suite of remotel
Authors
Michael L. Casazza, Austen Lorenz, Cory T. Overton, Elliott L. Matchett, Andrea Lynn Mott, Desmond Alexander Mackell, Fiona McDuie
Waterfowl recently infected with low pathogenic avian influenza exhibit reduced local movement and delayed migration
Understanding relationships between infection and wildlife movement patterns is important for predicting pathogen spread, especially for multispecies pathogens and those that can spread to humans and domestic animals, such as avian influenza viruses (AIVs). Although infection with low pathogenic AIVs is generally considered asymptomatic in wild birds, prior work has shown that influenza-infected b
Authors
Claire S. Teitelbaum, Michael L. Casazza, Fiona McDuie, Susan E. W. De La Cruz, Cory T. Overton, Laurie Anne Hall, Elliott Matchett, Josh T. Ackerman, Jeffery D. Sullivan, Andrew M. Ramey, Diann Prosser
Postbreeding movements and molting ecology of female gadwalls and mallards
The wing molt is an important annual life-history event that occurs in waterfowl and molt site selection can play an important role in determining survival. We tracked postbreeding movements of gadwall (Mareca strepera) and mallard (Anas platyrhynchos) females that bred in the Suisun Marsh (Suisun) of California, USA, to determine molt site selection and wing molt chronology. We attached backpack
Authors
Jeffrey D Kohl, Michael L. Casazza, Cory T. Overton, Mark P. Herzog, Josh T. Ackerman, Cliff L. Feldheim, John M. Eadie
Avian influenza antibody prevalence increases with mercury contamination in wild waterfowl
Environmental contamination is widespread and can negatively impact wildlife health. Some contaminants, including heavy metals, have immunosuppressive effects, but prior studies have rarely measured contamination and disease simultaneously, which limits our understanding of how contaminants and pathogens interact to influence wildlife health. Here, we measured mercury concentrations, influenza inf
Authors
Claire Stewart Teitelbaum, Josh T. Ackerman, Mason A. Hill, Jaqueline M. Satter, Michael L. Casazza, Susan E. W. De La Cruz, Walter M. Boyce, Evan James Buck, John M. Eadie, Mark P. Herzog, Elliott Matchett, Cory T. Overton, Sarah H. Peterson, Magdalena Plancarte, Andrew M. Ramey, Jeffery D. Sullivan, Diann Prosser
Yuma Ridgway’s rail selenium exposure and occupancy within managed and unmanaged emergent marshes at the Salton Sea
Yuma Ridgway’s rail (Rallus obsoletus yumanensis, hereafter, rail) is an endangered species for which patches of emergent marsh within the Salton Sea watershed comprise a substantial part of habitat for the species’ disjointed range in the southwestern United States. These areas of emergent marsh include (1) marshes managed by federal (particularly the U.S. Fish and Wildlife Service’s Sonny Bono S
Authors
Mark A. Ricca, Cory T. Overton, Thomas W. Anderson, Angela Merritt, Eamon Harrity, Elliott Matchett, Michael L. Casazza
Machine learned daily life history classification using low frequency tracking data and automated modelling pipelines: Application to North American waterfowl
BackgroundIdentifying animal behaviors, life history states, and movement patterns is a prerequisite for many animal behavior analyses and effective management of wildlife and habitats. Most approaches classify short-term movement patterns with high frequency location or accelerometry data. However, patterns reflecting life history across longer time scales can have greater relevance to species bi
Authors
Cory T. Overton, Michael L. Casazza, Joseph Bretz, Fiona McDuie, Elliott Matchett, Desmond Alexander Mackell, Austen Lorenz, Andrea Mott, Mark P. Herzog, Josh T. Ackerman
Pathways for avian influenza virus spread: GPS reveals wild waterfowl in commercial livestock facilities and connectivity with the natural wetland landscape
Zoonotic diseases are of considerable concern to the human population and viruses such as avian influenza (AIV) threaten food security, wildlife conservation and human health. Wild waterfowl and the natural wetlands they use are known AIV reservoirs, with birds capable of virus transmission to domestic poultry populations. While infection risk models have linked migration routes and AIV outbreaks,
Authors
Fiona McDuie, Elliott Matchett, Diann Prosser, John Y. Takekawa, Maurice E. Pitesky, Austen Lorenz, Madeline M McCuen, Cory T. Overton, Josh T. Ackerman, Susan E. W. De La Cruz, Michael L. Casazza