Calling Frog Survey: Results

From March to July since the year 2000 we’ve been venturing forth, morning to night, searching for the frogs and toads at various sites in more than eight Chicago Wilderness counties. Monitors have found all thirteen of the species known to occur in our region. Here’s a summary of who’s been found where, up to the 2003 monitoring season:

Based on abundance, the frogs and toads fell roughly into 3 groups:

Group 1: Chorus Frog, Green Frog, American Toad and Bullfrog were commonly discovered at most locations.

Group 2: Spring Peeper, Gray Treefrog and Northern Leopard Frog were less common but locally abundant during certain years.

Group 3: Eastern Gray Treefrog, Cricket Frog, Wood Frog, Fowlers Toad, Plains Leopard Frog and the Pickerel Frog were generally quite rare and local.

Numbers and species of frogs/toads recorded are highly dependant on temperature, weather and terrain, so their relative abundance varied from place to place and from year to year. Chorus Frogs were the only species found in every county, most commonly in Cook, DuPage, Kane, Lake, IL, and Will Counties. The rarest by far was the elusive Pickerel Frog, only recorded from Kane County, one July evening.

If Indiana were to have a contest for “State Frog”, the Spring Peeper would be a contender. This frog was the most commonly recorded species at all sites in Indiana. The Spring Peeper can be heard both morning and evening. As its name suggests, this is one of the first frogs to come out of hibernation, commonly heard from March to May, but occasionally in June.

Thanks to Jane Dorman for contributing to this analysis.