Gizzard nematodes of Canada geese wintering in southern Illinois

Gizzards from 64 hunter-shot Canada geese (Branta canadensis) were collected in southern Illinois (USA) in December 1991 and January 1992 to determine the prevalence and intensity of gizzard nematodes. Three species of gizzard nematodes were recovered: Amidostomum anseris, Amidostomum spatulatum, and Epomidiostomum crami. The prevalence of infection was 98%. Mean intensity was 17.8 nematodes per host and was significantly greater for immature geese (40.3 nematodes/host) than for adult geese (10.9 nematodes/host). The intensity of both A. anseris and E. crami was greater in immature geese, but even the most heavily infected birds did not display serious lesions. Despite a dramatic increase in the population of geese, mean intensity in adult geese was similar to mean intensity reported from earlier studies at the same site. Mean intensity in immature geese in 1991 and 1992 was greater than in earlier studies.