Rickert Nature Preserve Toads and Frogs
Deformed frogs have been reported in Minnesota since 1994. The original reports in 1994 and 1995 were restricted to a few localities and one species, Northern Leopard Frogs. In 1996, the number of reports and species involved increased tremendously There were reports of deformed frogs from over half the counties in the state, involving six species of frogs (Northern Leopard Frogs, Mink Frogs, Green Frogs, Gray Treefrogs, American Toads, and Spring Peepers). The affected populations ranged form 1% to 60% deformities. The deformities ranged from missing appendages, digits, and eyes to extra limbs, digits and skin membranes.
The current research into the deformed frogs has raised the public awareness and may have lead to some of the increased reporting, but not most of the increase. The lead researchers in this project, Dr. Judy Helgen (MN Pollution Control Agency), Dr. Robert McKinnell (University of Minnesota, St. Paul), and Dr. David Hoppe (University of Minnesota, Morris) have never encountered any deformed frogs in over fifty years of combined frog collecting, prior to 1994.
The deformed frogs have raised the concern of state legislators, to the point that they have provided $130,000 through the Legislatures Committee on Minnesota's Resources (LCMR) to Helgen, McKinnell, and Hoppe to investigate the problem in 1996. There was also a recent workshop held by the USEPA in Duluth, MN that was attended by over fifty persons from the across North America.
The causes of the deformities is still unknown. There are a number of theories and ideas as to the cause, but none have been proven in Minnesota. There are similar deformities to Minnesota's that have been reported in several states and provinces.
Persons wanting detailed information on this topic should address their questions to Judy Helgen or Mark Gernes at MNPCA, Water Quality Division, 520 Lafayette Road, St. Paul, MN 55155.