Waterfowl Breeding Population and Habitat Survey
The Waterfowl Breeding Population and Habitat Survey is the most extensive and most important of North America's waterfowl population surveys. It was started experimentally in 1947, became operational in 1955, and has been conducted every year since then.
This survey is a cooperative effort of the United States Fish and Wildlife Service, the Canadian Wildlife Service, and state, provincial, and tribal agencies. It currently covers more than 2.1 million square miles of the northern United States and Canada, and includes most of the primary duck nesting areas in North America.
Each year, air crews (a pilot biologist and an observer) fly fixed-wing aircraft at low altitude (150 ft) over transect lines through waterfowl habitat areas. Over 55,000 miles of transects are flown every year. That’s like counting ducks in a single line over two times around the world!
Because some birds cannot be seen from the air, ground crews conduct similar counts in some survey areas. Using the difference in the two counts, biologists develop visibility correction factors to apply to aerial counts.
Estimates of breeding populations for all waterfowl species observed are derived by taking the aerial counts, adjusting them based on the visibility correction factors, and expanding them over the survey area.
The most recent results for this survey are available in the Status of Waterfowl section of this website.