Mike Casazza's research program at the Dixon Field Station focuses on the ecology of waterfowl and wetland management in the Pacific Flyway.
RESEARCH INTERESTS
Mike and his team are experts in wildlife telemetry and apply cutting edge tools to answer complex ecological questions. In addition, Mike’s program also focuses on threatened and endangered species in a variety of ecosystems including primary ecological research on the endangered California Ridgway's Rail in SF Bay, the endangered San Francisco Gartersnake, the threatened Giant Gartersnake in the Central Valley of California, the California state-listed Greater Sandhill Crane, and the Greater Sage-Grouse. Mike Casazza's research has targeted studies which provide critical species information to land managers responsible for maintaining diverse and healthy wildlife populations while trying to help recover special status species. Understanding key life history traits of special status species can lead to management options promoting species recovery.
EDUCATION
- 1995 M.S. California State University, Sacramento Thesis: Habitat use and movement of Northern Pintails wintering in Suisun Marsh, CA
- 1988 B.S. Wildlife Biology, U.C. Davis
Science and Products
To catch a (marsh) predator: Modified trapping methods for breeding and wintering Northern Harriers (Circus hudsonius)
Functional wetland loss drives emerging risks to waterbird migration networks
Assessment of waste grain densities to aid waterfowl conservation in the Klamath Basin of northeastern California and southeastern Oregon
Pathways for avian influenza virus spread: GPS reveals wild waterfowl in commercial livestock facilities and connectivity with the natural wetland landscape
Host correlates of avian influenza virus infection in wild waterfowl of the Sacramento Valley, California
Megafires and thick smoke portend big problems for migratory birds
Migration stopover ecology of Cinnamon Teal in western North America
Wetland availability and salinity concentrations for breeding waterfowl in Suisun Marsh, California
Informing wetland management with waterfowl movement and sanctuary use responses to human-induced disturbance
A tale of two valleys: Endangered species policy and the fate of the giant gartersnake
Changes in the abundance and distribution of waterfowl wintering in the Central Valley of California, 1973–2000
A customized framework for regional classification of conifers using automated feature extraction
Goose Population Dynamics in the California Central Valley and Pacific Flyway
Webinar: Linking Remote Sensing and Bird Behavior Data to Understand the Impacts of Drought on Waterfowl
Suisun Marsh Waterfowl and Wildlife Studies
Waterfowl Ecology in California and the Pacific Flyway
Ecology and Population Dynamics of Ridgway's Rails along the West Coast of the U.S.
Dixon Field Station
The Impact of Drought on Waterbirds and Their Wetland Habitats in California’s Central Valley
Effects of Sea-Level Rise and Extreme Storms on California Coastal Habitats: Part 1
Fate of Endangered Species in San Francisco Bay Tidal Marshes with Sea-Level Rise
Selenium concentrations in Yuma Ridgway's Rails occupying managed and unmanaged emergent marshes at the Salton Sea
Yuma Ridgway's Rail (Rallus obsoletus yumanensis) Population Surveys, Rail Movement, and Potential Habitat at the Salton Sea of California
Suisun Tidal Marsh Duck Use Dataset
Migration stopover ecology of cinnamon teal in western North America
Waterfowl Disturbance in California and Nevada (2018)
Locations of Pacific Flyway Ducks in and near Commercial Livestock Facilities of the Western USA (2015-2021)
Tule Greater White-fronted Goose Migration Tracks (2019-2020) and Atmospheric Smoke Concentrations (2020).
Tracking Data for Greater White-fronted Geese (Anser albifrons)
Comparisons of Gambel's quail survey methods conducted in 2016 within the Mohave Desert of California with results and summaries
Impounded and tidal wetland plant diversity and composition across spatial scales, San Francisco Bay-Delta, California, USA (2016-2018)
Classification of Waterfowl Habitat, and Quantification of Interannual Space Use and Movement Distance from Primary Roosts to Night Feeding Locations by Waterfowl in California for October - March of 2015 through 2018
Coastal California San Francisco Gartersnake Capture-Mark-Recapture Data (2008-2013)
Science and Products
- Publications
Filter Total Items: 170
To catch a (marsh) predator: Modified trapping methods for breeding and wintering Northern Harriers (Circus hudsonius)
Although there are a variety of methods available for trapping raptors, some species, such as Northern Harriers (Circus hudsonius), are not easily captured with standard methods. We tested several existing trapping methods and modified two of them based on Northern Harrier ecology and behavior across seasons in a study population in California. No previously successful methods described in the litFunctional wetland loss drives emerging risks to waterbird migration networks
Migratory waterbirds (i.e., shorebirds, wading birds, and waterfowl) rely on a diffuse continental network of wetland habitats to support annual life cycle needs. Emerging threats of climate and land-use change raise new concerns over the sustainability of these habitat networks as water scarcity triggers cascading ecological effects impacting wetland habitat availability. Here we use important waAssessment of waste grain densities to aid waterfowl conservation in the Klamath Basin of northeastern California and southeastern Oregon
Post-harvest waste seed from cereal grains is a major dietary component of waterfowl in the Klamath Basin in northeastern California and southeastern Oregon, a region that plays host to over a million waterfowl annually. Understanding food abundance is critical to local waterfowl management, therefore we conducted a study in 2008 to investigate waste grain densities in barley, oat and wheat fieldsPathways 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,Host correlates of avian influenza virus infection in wild waterfowl of the Sacramento Valley, California
Avian influenza viruses (AIVs) are distributed globally in members of the family Anatidae (waterfowl), and significant disease may occur when these viruses infect commercial poultry or humans. Early detection of AIV through surveillance of wild waterfowl is one measure to prevent future disease outbreaks. Surveillance efforts that are designed to account for host and environmental determinants ofMegafires and thick smoke portend big problems for migratory birds
In 2020, the fire season affecting the western United States reached unprecedented levels. The 116 fires active in September consumed nearly 20,822 km2 (https://inciweb.nwcg.gov/accessible-view/ Accessed 2020-09-29) with eighty percent of this footprint (16,567 km2) from 68 fires occurring within California, Oregon, and Washington. Although the 2020 fire season was the most extreme on record, it eMigration stopover ecology of Cinnamon Teal in western North America
Identifying migration routes and fall stopover sites of Cinnamon Teal (Spatula cyanoptera septentrionalium) can provide a spatial guide to management and conservation efforts, and address vulnerabilities in wetland networks that support migratory waterbirds. Using high spatiotemporal resolution GPS-GSM transmitters, we analyzed 61 fall migration tracks across western North America during our threeWetland availability and salinity concentrations for breeding waterfowl in Suisun Marsh, California
Availability of wetlands with low salinities during the breeding season can influence waterfowl reproductive success and population recruitment. Salinities as low as 2 ppt (3.6 mScm–1) can impair duckling growth and influence behavior, with mortality occurring above 9 ppt (14.8 mScm–1). We used satellite imagery to quantify the amount of available water, and sampled surface water salinity at GrizzInforming wetland management with waterfowl movement and sanctuary use responses to human-induced disturbance
Long-term environmental management to prevent waterfowl population declines is informed by ecology, movement behavior and habitat use patterns. Extrinsic factors, such as human-induced disturbance, can cause behavioral changes which may influence movement and resource needs, driving variation that affects management efficacy. To better understand the relationship between human-based disturbance anA tale of two valleys: Endangered species policy and the fate of the giant gartersnake
By the mid-20th Century, giant gartersnakes (Thamnophis gigas) had lost more than 90% of their Central Valley marsh habitat and were extirpated from more than two-thirds of their range. This massive habitat loss led to their inclusion in the inaugural list of rare species under the California Endangered Species Act (CESA). Listing under the CESA provided giant gartersnakes legal protection and mecChanges in the abundance and distribution of waterfowl wintering in the Central Valley of California, 1973–2000
The Central Valley of California is one of the most important areas for wintering waterfowl in the world and the focus of extensive conservation efforts to mitigate for historical losses and counter continuing stressors to habitats. To guide conservation, we analyzed trends in the abundance and distribution (spatiotemporal abundance patterns) of waterfowl and their habitats in the Central Valley aA customized framework for regional classification of conifers using automated feature extraction
Pinyon and juniper expansion into sagebrush ecosystems is one of the major challenges facing land managers in the Great Basin. Effective pinyon and juniper treatment requires maps that accurately and precisely depict tree location and degree of woodland development so managers can target restoration efforts for early stages of pinyon and juniper expansion. However, available remotely sensed layers - Science
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.Suisun Marsh Waterfowl and Wildlife Studies
Suisun Marsh provides critical habitat for wintering and breeding waterbirds in California. USGS WERC collaborates with the California Department of Water Resources to examine trends in bird declines and to assess the habitat factors driving long-term survival of waterfowl, rails, and other birds in this important area.Waterfowl Ecology in California and the Pacific Flyway
The Suisun Marsh and Central Valley in California offer some of the world’s most important wetland habitats for waterfowl in the Pacific Flyway. Mike Casazza and USGS WERC biologists are providing the science to support and evaluate waterfowl populations and habitat management in North America.Ecology and Population Dynamics of Ridgway's Rails along the West Coast of the U.S.
The Ridgway’s rail is a federal and state listed endangered species that occurs in wetlands along the Pacific Coast and from the Lower Colorado River drainage to southern Baja California. Three subspecies of Ridgway’s rail are found within the United States: the California Ridgway’s Rail, Yuma Ridgway’s rail, and Light-footed Ridgway’s rail. All three subspecies have declined since 1900 as a...Dixon Field Station
WERC scientists at the Dixon Field Station conduct studies from the San Francisco Bay-Delta in California to the Great Basin spanning California and Nevada.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 storFate 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 - Data
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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. FYuma 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, renamedSuisun 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., AckeMigration stopover ecology of cinnamon teal in western North America
Identifying migration routes and fall stopover sites of cinnamon teal (Spatula cyanoptera septentrionalium) can provide a spatial guide to management and conservation efforts, and address vulnerabilities in wetland networks that support migratory waterbirds. Using high spatio-temporal resolution GSM-GPS transmitters, we tracked the fall migration of 61 cinnamon teal across western North America ovWaterfowl Disturbance in California and Nevada (2018)
Long-term environmental management to prevent waterfowl population declines is informed by ecology, movement behavior and habitat use patterns. Extrinsic factors such as human-induced disturbance can cause behavioral changes which may influence movement, and resource needs, driving variation that affects management efficacy. To better understand the relationship between human-based disturbance andLocations of Pacific Flyway Ducks in and near Commercial Livestock Facilities of the Western USA (2015-2021)
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 outbreaksTule Greater White-fronted Goose Migration Tracks (2019-2020) and Atmospheric Smoke Concentrations (2020).
April through May (spring) and August through September (fall) locations for tule greater white-fronted geese (Anser albifrons elgasi) marked with GPS collars at Summer Lake Wildlife Area, OR in 2018 and 2019. Locations may include pre-migration and post-migration designations. Locations occurring between September 11, 2020, and arrival at, or within 50 kilometers of the Summer Lake Wildlife AreaTracking Data for Greater White-fronted Geese (Anser albifrons)
This metadata document describes VHF tracking data for Greater White-fronted Geese (Anser albifrons) that were marked annually from 1987 to 1991 in Alaska and the Klamath Basin (Oregon and California) and subsequently tracked through the Pacific Flyway (primarily in Alaska, California, and Mexico). Only tracking data for geese marked or located, at least once, in Alaska are included in this data pComparisons of Gambel's quail survey methods conducted in 2016 within the Mohave Desert of California with results and summaries
Data includes results collected in the Mohave Desert during 2016 using three survey methods (acoustic recording units, camera traps, and call-count surveys) to detect gamebirds, primarily Gambel's quail (Callipepla gambelii) but also including records of mourning dove (Zenaida macroura), Eurasian collared-dove (Streptopelia decaocto), and chukar (Alectoris chukar). ARU data includes the SelectionsImpounded and tidal wetland plant diversity and composition across spatial scales, San Francisco Bay-Delta, California, USA (2016-2018)
These datasets provide information on plant alpha, beta, and gamma diversity, and plant species abundance at several spatial scales for tidal wetlands along a salinity gradient in the San Francisco Bay-Delta and an impounded brackish wetland complex in Suisun Marsh, California. Files include diversity metrics calculated at the patch, site, and region scales, average percent cover of wetland dominaClassification of Waterfowl Habitat, and Quantification of Interannual Space Use and Movement Distance from Primary Roosts to Night Feeding Locations by Waterfowl in California for October - March of 2015 through 2018
Technological advancements in Global Positioning System (GPS) telemetry markers allow almost real-time observation of waterfowl movements and habitat selection. Telemetry data on ducks marked with GPS transmitters can be used to evaluate performance of remote sensing data (for example, dynamic open-water maps produced by Point Blue Conservation Science) for classifying habitats that are flooded anCoastal California San Francisco Gartersnake Capture-Mark-Recapture Data (2008-2013)
These data are multi-state capture histories of 273 individual San Francisco gartersnakes collected at a site before and after a portion of the site was burned. Data collection began in 2008 and continued until 2013, and the prescribed fire was applied in the fall of 2010. These data support the following paper: Halstead, B. J., Thompson, M. E., Amarello, M. , Smith, J. J., Wylie, G. D., Routman, - News