Summary

Description

Three federally listed endangered bat species are known to inhabit Oklahoma. The gray bat Myotis grisescens is probably the most abundant, and is presently known to occur in Adair, Cherokee, Delaware, and Ottawa Counties. The Indiana bat Myotis sodalis is rare in Oklahoma, but is considered to be present in Adair, Delaware, LeFlore, and Pushmataha Counties. The Ozark bigeared bat Piecotus townsendii ingens is probably a relict population which has always been small in number. In addition to human disturbance and destruction of habitat, pesticides are often cited as one of the potential major causes in the decline of endangered bat species. Several cases of pesticide poisoning have been reported for gray bats Clark et al 1978, Clark et al 1983, Clawson and Clark 1989. Endangered bat species in Oklahoma feed exclusively on insects, and in fact, food habits within a species may be relatively restricted. The U.S. Fish and Wildlife Service established Oklahoma Bat Caves National Wildlife Refuge in 1985 to protect endangered bats by preserving and managing several of their known cave habitats. In an effort to better assess the overall status of the populations inhabiting these caves, samples of Ozark bigeared bat and gray bat guano were collected from caves and analyzed for contaminants. In addition, during the course of other, ongoing studies related to the bats, dead individuals were encountered on the floor of the caves and were collected for chemical analysis. The purpose of this report is to present the results of contaminant analyses on these samples.