In July a portion of the lines surveyed in May during the Breeding Waterfowl Survey are surveyed to obtain information on duck production. These counts yield measures of duck production and give an idea of the timing of nesting chronology for the year, assess water body abundance, and result in a qualitative assessment of July habitat conditions. The July brood counts are not adjusted for visibility bias and thus provide only a relative index rather than a direct estimate. The July Duck Production Survey is helpful in predicting the number of ducks to be expected during the Fall hunting season. Each May and June the Canadian Wildlife Service and the U.S. Fish and Wildlife Service survey breeding waterfowl from the north-central U.S. throughout Canada and Alaska.
Survey biologists estimate numbers and species from airplanes flown along transects.
A portion of the transects are then surveyed from the ground by biologists who census all waterfowl. The ground census corrects for birds not counted by the aerial team. This survey is the most extensive wildlife survey in the world, and its results are a major factor used in setting annual duck-hunting regulations. Winter Surveys Many geese and ducks can't be counted in the spring and summer on breeding areas because they either can't be surveyed using airplanes or they nest in remote and inaccessible Arctic areas. Abundance indices for these species are obtained from surveys on wintering areas.