Waterfowl Ecology in California and the Pacific Flyway

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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.

Suisun marsh and waterfowl

Waterfowl in Suisun Marsh

(Public domain.)

Suisun Marsh and Central Valley: A Critical Wetland Habitat for Waterfowl

California’s Suisun Marsh and Central Valley provide critical breeding and wintering habitat for many waterfowl in the Pacific Flyway. Together, these areas provide for 60 percent of wintering Pacific Flyway waterfowl and 20 percent of the waterfowl in North America annually.

However, the state’s growing population, increasing demand for water, and regional losses of wetland habitats present considerable challenges for waterfowl and waterbird conservation and management. To support and inform ongoing conservation efforts, Mike Casazza and USGS WERC biologists are leading projects on the following:

  • Population size for wintering waterfowl in Suisun Marsh and the Central Valley.
  • Waterfowl habitat use and movements using telemetry.
  • Waterfowl body condition, health, and changes in these over time.
  • Long-term trends in nest survival and nest density in Suisun Marsh and nesting ecology of waterfowl related to nest predators, their alternative prey, hen quality and fidelity.
  • Duckling survival, brood ecology, habitat use, and movements in relation to wetland habitats and salinity in Suisun Marsh.
  • Long-term trends in waterfowl demographic rates and population viability in the Pacific Flyway.
  • Value of food types and different wetland habitats used by waterfowl in Suisun Marsh and other regions in California, and habitat carrying capacity for waterfowl.  This will include evaluating impacts of habitat management and wetland and upland restoration on waterfowl in Suisun Marsh.
  • Use banding data and satellite radio-markers to provide more reliable and accurate demographic information, understand and assess spatial habitat use, determine population status, and Cinnamon Teal responses to harvest and habitat management in eight major breeding sites across the west.
  • Effects of long-term drought on waterfowl in Suisun Marsh and the Central Valley. 

For a look at the team's field work from start to finish, explore the photo gallery below. Click "fullscreen" for the best quality.