Amphibians

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Taxonomy in the amphibian checklist closely follows the standard field guide to eastern and central North American species by Conant and Collins (1991) and Salamanders of the United States and Canada (Petranka 1998). Species are listed alphabetically under each family. In some cases, a subspecies is designated. We followed this practice only when a single subspecies is known from the state and there is no question as to its identity. Common names follow Crother, et al. (2000).

The final revision of the checklist contains 19 amphibian species in 7 families. All 19 species are native. No Wisconsin amphibians are listed as endangered or threatened at the federal level. Blanchard's Cricket Frog (Acris crepitans blanchardi) is listed as endangered at the state level. No amphibians are listed as threatened at the state level.

Excluded Amphibian Species

We exclude Tremblay's Salamander (Ambystoma tremblayi) from the checklist. Vogt (1981) included an account for Tremblay's Salamander in his treatment of the Wisconsin herpetofauna, but this "species" is now known to be a triploid, unisexual variety of hybrid origin (between Jefferson's Salamander [Ambystoma jeffersonianum] and Blue-spotted Salamander [Ambystoma laterale]).

The Wisconsin Herpetological Literature

The literature dealing with the ecology, life history, status, history, and distribution of Wisconsin's amphibians is scattered in a plethora of journals, bulletins, and sometimes-obscure reports. Extensive bibliographies providing access to this literature have been compiled (Dlutkowski, et al. 1987, Watermolen 1992), and a comprehensive bibliography is now available on the Milwaukee Public Museum's web site. Updating this bibliography is an on-going cooperative project.

Amphibian Survey and Atlas Efforts

Amphibians are the subjects of several on-going survey and atlas efforts. The Wisconsin Herpetological Atlas Project tracks the distributions of amphibians (and reptiles) in Wisconsin. The Milwaukee Public Museum, with the cooperative support of the DNR's Bureau of Endangered Resources, and The Nature Conservancy, initiated the Herpetological Atlas Project in 1986. The Herpetological Atlas is producing a computerized database of amphibian distribution, based on records obtained from museum collections, field surveys, literature, and field notes provided by volunteer observers throughout the state. Over 30,000 records have been received, and over 450 new county records have been confirmed since the project began. The data collected help in mapping species distributions, documenting rare species occurrences, analyzing population trends, examining habitat requirements, and planning conservation priorities. Preliminary results of the Herpetological Atlas Project are presented in Casper (1996, 1998). For more information on the Herpetological Atlas Project, readers are encouraged to visit the project's web site.

The Wisconsin Frog and Toad Survey is an on-going survey coordinated by the DNR. The survey was initiated in 1984, and relies heavily on volunteer efforts. Background information on the survey is included in Mossman and Hine (1985), and the history, analytical techniques, distribution maps, and trend results through 1995 are thoroughly summarized in Mossman, et al. (1998). Survey routes are distributed statewide, with a goal of two survey routes in each county. Routes consist of 10 sites that are monitored 3 times annually (8-30 April, 20 May - 5 June, and 1-15 July). Presence/absence of each species is determined for each site based on the breeding calls of male frogs. The relative number of calling individuals at each site ranks the abundance of each species. Survey data are statistically analyzed and a calling index to the route populations is calculated. These route populations are regressed over years to create a species population trend (Dhuey and Hay 1999).

Amphibian Species List

Last Revised: Friday October 17 2008