Hey, J. and E. Farrar. 2001. Surveying ephemeral wetlands for plains spadefoot toads,, Spea bombifrons and Woodhouse's toads, Bufo woodhousei, in Southwestern Minnesota. Final report submitted to the Minnesota Department of Natural Resources. 15 pp.
Our objectives were to determine if Spea bombifrons and Bufo woodhousei occur in southwestern Minnesota. If these species were found we would describe their breeding habitats, characterize the spadefoot tadpoles' ephemeral community and develop a listening protocol. During the summer of 2000 we surveyed for these species using night driving and listening for calling males along preselected routes in Rock and Pipestone counties. However, rainfall was insufficient to provide optimal spadefoot calling conditions during our survey period, and neither species was heard. In 2001 rainfall was abundant during May and June and soils were hydrated. We surveyed our routes, mainly along the western border of Minnesota and South Dakota, in late June under optimal spadefoot calling conditions (warm, rainy nights with water standing in fields, following afternoon thunderstorms). However we heard no spadefoot toads or Woodhouse's toads. A potential Woodhouse's toad call recording sent to us by Carol Hall, Minnesota DNR, from Grant County turned out not to be Bufo woodhousei. It is probably either Bufo hemiophrys or a hybrid of that species with Bufo americanus. We conclude that even though the species of interest have been reported near the Minnesota border in neighboring states, it is unlikely that they occur in the counties that we surveyed.