 He was chairman of the IUCN Species Survival Commission from 1989 to 1996 and later served as a board member for the Center for Humans and Nature as well as for the Illinois State Museum.Rabb published widely on such topics as the evolutionary relationships of viperid snakes, behavioral development in okapi, social behavior in captive wolf packs, and breeding behavior of pipid frogs.He founded the Declining Amphibian Populations Task Force and was active in amphibian conservation issues with the Amphibian Survival Alliance and the Amphibian Ark.