Eustrongylides and pesticide levels in a great blue heron shot in Wisconsin

The parasitic roundworm, Eustrongylides ignotus Jagersk, has been known to cause mortality and morbidity in members of the heron family in the eastern states of North America. To date no previous records exist for this nematode in Wisconsin. Even though eustrongylidiosis was first detected in the District of Columbia in 1926 by Chapin (1926), it was not until 1976 that this parasite was found in the midwest, in central Indiana (Winterfield and Kazacos 1977). The purpose of this report is to document the occurrence of this nematode even further westward in Wisconsin, and to show the debilitating effect it can have on herons.