Distribution of Strecker's chorus frogs in relation to their tolerance for freezing. Packard, G. C., J. K. Tucker, and L. D. Lohmiller. 1998. Distribution of Strecker's chorus frogs (Pseudacris streckeri) in relation to their tolerance for freezing. Journal of Herpetology 32(3):437 440. Reprinted by U.S. Geological Survey, Upper Midwest Environmental Sciences Center, La Crosse, Wisconsin, February 1999. LTRMP 99-R003. 4 pp. (NTIS #PB99-134637) ABSTRACT We examined the response of Strecker's chorus frog (Pseudacris streckeri) and the western chorus frog (P. triseriata) to subfreezing temperatures. Both species were collected in west-central Illinois. We found that the western chorus frog could survive freezing at temperatures between -1.2øC and -1.6øC; eight of eight frogs tested survived. In contrast, Strecker's chorus frog could not survive freezing at these same temperatures (one of nine survived). These results are consistent with the geographic ranges of the species with the western chorus frog being widely distributed even in cold regions of North America and Strecker's chorus frog limited to more southern regions. Lack of freeze tolerance may be why more northerly populations of P. streckeri are limited to habitats with sand substrates. Only here can the frog bury deeply enough to escape freezing. KEYWORDS Anurans, freeze tolerance, Illinois, overwinter survival, Pseudacris, Pseudacris streckeri, Pseudacris triseriata