Are amphibian malformations and population declines linked?
GRAY, ROBERT1, 1 ABSTRACT- The cricket frog, Acris crepitans, has undergone a dramatic decline in the upper Midwestern United States and Canada where it was once abundant. It is on the endangered species list in Minnesota, Wisconsin and Ontario, Canada, threatened in New York, and a species of special concern in Indiana, Michigan and West Virginia. The species may even be extinct in Minnesota and Ontario, Canada. Concurrent with population declines of other amphibian species, reports of malformed individuals have been increasing. Reported amphibian malformations include external deformities, mostly missing hindlimbs, but also missing forelimbs, extra arms and legs, missing eyes and mandibles, as well as internal abnormalities involving the bladder, digestive system and testes. From 1968 through 1971, I studied the adaptive significance of color polymorphism in the cricket frog in Illinois and kept detailed records of the condition of each individual. Evaluation of data for almost 10,00
