Computer-aided procedure for counting waterfowl on aerial photographs

Examination of 46 Canada goose goslings yielded 14 species of parasites, including five Protozoa, four Nematoda, two Cestoda, and three Trematoda. Evidence indicates that goslings acquired most of these infections during their first week of life. Some parasites, Prosthogonimus sp., occurred only in younger birds. Others, Leucocytozoon simondi, were evident only during the initial course of infection, while still others remained evident in older geese. Parasites with a direct life cycle appeared to be more prevalent than those requiring intermediate hosts. Among 29 birds from a refuge in Michigan, 14 species of parasites were found; while in 17 goslings from a Utah refuge, only five species occurred.