Michael Casazza
Biography
RESEARCH INTERESTS
Mike Casazza's research program at the Dixon Field Station focuses on the ecology of waterfowl and wetland management in the Pacific Flyway. 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
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...
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...
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...
Geospatial data for object-based high-resolution classification of conifers within greater sage-grouse habitat across Nevada and a portion of northeastern California (ver. 2.0 July 2018)
These products were developed to provide scientific and correspondingly spatially explicit information regarding the distribution and abundance of conifers (namely, singleleaf pinyon (Pinus monophylla), Utah juniper (Juniperus osteosperma), and western juniper (Juniperus occidentalis)) in Nevada and portions of northeastern California. Encroachment of these trees into sagebr
Geospatial data for object-based high-resolution classification of conifers within the geographic range of the Bi-State Distinct Population Segment of greater sage-grouse in California and Nevada
These products were developed to provide scientific and correspondingly spatially explicit information regarding the distribution and abundance of conifers (namely, singleleaf pinyon (Pinus monophylla), Utah juniper (Juniperus osteosperma), and western juniper (Juniperus occidentalis)) in Nevada and portions of northeastern California. Encroachment of these trees into sagebr
Coastal 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.
Microhabitat and Vegetation Selection by Giant Gartersnakes Associated with a Restored Marsh in California
These data describe differences in percent cover of microhabitats and vegetation types at giant gartersnake locations and random points paired with giant gartersnake locations for use in case-control logistic regression. The data also include information on the individual snake, the year of observation, and whether the individual had moved from its previous location to allow for correlation o...
A Century of Landscape Disturbance and Urbanization of the San Francisco Bay Region affects the Present-day Genetic Diversity of the California Ridgway’s Rail (Rallus obsoletus obsoletus).
Fragmentation and loss of natural habitat have important consequences for wild populations and can negatively affect long-term viability and resilience to environmental change. Salt marsh obligate species, such as those that occupy the San Francisco Bay Estuary in western North America, occupy already impaired habitats as result of human development and modifications and are highly susceptible...
Megafires 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....
Overton, Cory T.; Lorenz, Austen; James, Eric P; Ahmadov, Ravan; Eadie, John M.; McDuie, Fiona; Petrie, Mark J.; Nicolai, Chris A.; Weaver, Melanie L; Skalos, Daniel A; Skalos, Shannon; Mott, Andrea Lynn; Mackell, Desmond Alexander; Kennedy, Anna; Matchett, Elliott L.; Casazza, Michael L. Migration 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...
Mackell, Desmond Alexander; Casazza, Michael L.; Overton, Cory T.; Donnelly, J. Patrick; Olson, David; McDuie, Fiona; Ackerman, Joshua T.; Eadie, John M. Wetland 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...
Schacter, Carley Rose; Peterson, Sarah H.; Herzog, Mark P.; Hartman, C. Alex; Casazza, Michael L.; Ackerman, Joshua T. Informing 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...
McDuie, Fiona; Lorenz, Austen; Klinger, Robert C.; Overton, Cory T.; Feldheim, Cliff L.; Ackerman, Joshua T.; Casazza, Michael L. A 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...
Halstead, Brian J.; Valcarcel, Patricia; Kim, Richard; Jordan, Anna; Rose, Jonathan P.; Skalos, Shannon; Reyes, Gabriel; Ersan, Julia; Casazza, Michael L.; Essert, Allison; Fulton, Alexandria M Changes 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...
Fleskes, Joseph P.; Casazza, Michael L.; Overton, Cory T.; Matchett, Elliott L.; Yee, Julie L. A 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...
Roth, Cali L.; Coates, Peter S.; Gustafson, K. Benjamin; Chenaille, Michael; Ricca, Mark A.; Sanchez-Chopitea, Erika; Casazza, Michael L. Nocturnal incubation recess and flushing behavior by duck hens
Incubating birds must balance the needs of their developing embryos with their own physiological needs, and many birds accomplish this by taking periodic breaks from incubation. Mallard (Anas platyrhynchos) and gadwall (Mareca strepera) hens typically take incubation recesses in the early morning and late afternoon, but recesses can also take...
Croston, Rebecca; Peterson, Sarah H.; Hartman, C. Alex; Herzog, Mark P.; Feldheim, Cliff L.; Casazza, Michael L.; Ackerman, Joshua T. Interrupted incubation: How dabbling ducks respond when flushed from the nest
Nesting birds must provide a thermal environment sufficient for egg development while also meeting self‐maintenance needs. Many birds, particularly those with uniparental incubation, achieve this balance through periodic incubation recesses, during which foraging and other self‐maintenance activities can occur. However, incubating birds may...
Croston, Rebecca; Hartman, C. Alex; Herzog, Mark P.; Peterson, Sarah H.; Kohl, Jeffrey; Overton, Cory T.; Feldheim, Cliff L.; Casazza, Michael L.; Ackerman, Joshua T.
Using high resolution satellite and telemetry data to track flooded habitats, their use by waterfowl, and evaluate effects of drought on waterfowl and shorebird bioenergetics in California
Wetland managers in the Central Valley of California, a dynamic hydrological landscape, require information regarding the amount and location of existing wetland habitat to make decisions on how to best use water resources to support multiple wildlife objectives, particularly during drought. Scientists from the U.S. Geological Survey Western...
Matchett, Elliott L.; Reiter, Matthew; Overton, Cory T.; Jongsomjit, Dennis; Casazza, Michael L. Seasonal impoundment alters patterns of tidal wetland plant diversity across spatial scales
Understanding patterns of biodiversity is a key goal of ecology and is especially pressing in the current human‐caused biodiversity crisis. In wetland ecosystems, human impacts are centered around hydrologic manipulation including the common practice of wetland diking and impoundment. Constraining how wetland management influences plant...
Jones, Scott; Janousek, Christopher N.; Casazza, Michael L.; Takekawa, John Y.; Thorne, Karen M. Waterfowl use of wetland habitats informs wetland restoration designs for multi‐species benefits
Extensive global estuarine wetland losses have prompted intensive focus on restoration of these habitats. In California, substantial tracts of freshwater, brackish and tidal wetlands have been lost. Given the anthropogenic footprint of development and urbanization in this region, wetland restoration must rely on conversion of existing habitat...
Casazza, Michael L.; McDuie, Fiona; Jones, Scott; Lorenz, Austen; Overton, Cory T.; Yee, Julie L.; Feldheim, Cliff L.; Ackerman, Joshua T.; Thorne, Karen M.
Research Spotlight: Dabbling Ducks Prefer Managed Wetlands and Pond-Like Features in Suisun Marsh
A recent study by USGS scientists found that dabbling ducks in Suisun Marsh, California, spend about 98% percent of their time in managed wetlands, consistently selecting managed wetlands over tidal marsh habitat.
Dabbling Duck Flight Speeds: High Tech Update For the 21st Century
In a recent study, U.S. Geological Survey biologists used technologically advanced GSM-GPS transmitters to calculate migratory and non-migratory flight speeds of six species of dabbling ducks. The highly improved flight speed estimates are the first in nearly a century and provide the science for resource managers to better estimate food and habitat requirements for dabbling ducks.
Research Spotlight: California Central Valley Ducks Move Shorter Distances and Use Smaller Areas Than Expected
In a new publication, U.S. Geological Survey biologists report the results of real-time tracking of three species of dabbling ducks in California’s Central Valley with GPS to examine the ducks’ fine-scale 24-hour movement patterns.
Secrets of Suisun Marsh's Birds of Prey
Did you know that the USGS is studying raptors in California? Biologists with the USGS Western Ecological Research Center are hard at work in the field, learning more about the ecology of Northern Harriers and their interactions with migratory waterfowl of concern to the U.S. Fish and Wildlife Service.
Livestock grazing effects on sage-grouse: study identifies options to sustain ranching and help wildlife
Effects of livestock grazing on greater sage-grouse populations can be positive or negative depending on the amount of grazing and when grazing occurs, according to research published today in Ecological Applications. The research was conducted by scientists from the United States Geological Survey, Colorado State University and Utah State University.
Cumulative Effects of Wildfire Adversely Affect Greater Sage-Grouse in the Great Basin
Slowing fire-related population declines in greater sage-grouse in the Great Basin over the next 30 years may depend on the intensity of fire suppression efforts in core breeding areas and long-term patterns of precipitation, according to a just-published USGS-led study.