Science activity

The California breeding population survey is modeled after the continental breeding survey. Though most of the wintering waterfowl in California breed outside of the state, California still has a significant number that both breed and winter here. CDFW and California Waterfowl Association (CWA) biologists conduct the California survey. Surveyed areas include wetland and agricultural areas in northeastern California, throughout the Central Valley, the Suisun Marsh, and some coastal valleys. CDFW biologists and warden-pilots use a fixed-wing aircraft to fly all of the transects while CWA completes the "ground" portion of the survey using a helicopter. This survey also utilizes a visibility correction factor. For the most part, ducks that only winter in California comprise most of the harvest, but CDFW augments the continental survey assessment with the estimates of California's breeding population for developing hunting regulation recommendations.