Scheduling censuses of breeding white pelicans (Pelecanus erythrorhynchos) in northern Alberta
Beaver, RD.; Lewin, V.
Canadian Field-Naturalist 952: 198-201
In May 1976 and June 1977 aerial surveys were flown over Birch Lake in northeastern Alberta to determine the numbers of white pelicans (P. erythrorhynchos) occupying nests. Ground counts conducted concurrently with the 1977 aerial surveys revealed that the aerial counts included some pelicans not occupying nests. Pelicans that were present but not occupying nests were loafing birds, either non-breeders, mates off the nest or both. Evening rather than morning census flights are preferable because the number of such loafing pelicans appeared then to be lower. Censuses to record numbers of incubating pelicans in northern Alberta should be conducted in late May or early June during the peak of the incubation period.