Natural Features of the PA Watershed

--Frog/Toad Data from DNR:

The Michigan Department of Natural Resources coordinates frog and toad surveys for designated routes throughout the state. Each route contains ten sites that are visited three times annually. Three of these routes include sites in the Portage Creek subwatershed. (Seven sites are in the subwatershed.) Routes have been traversed three times each spring (April, May and June) of each year from 1996 to 2001. (Note: data is not available for year 2000.) Field personnel stop at predetermined sites and record the number of calls heard from various frog and toad species. The following graph illustrates the total calls heard at the sites in the Portage Creek subwatershed for each year of the study. The sites are all located in the Gourdneck State Game Area, around Hampton Lake.

Frog and Toad Data for Sites in Portage Creek Subwatershed (View the Enlarged Graph)

Thirteen species of anurans (frogs and toads) are native to Michigan. Of those 13 species, all except the mink frog have been heard in Kalamazoo County at least once during the spring surveys. Nine of these thirteen species have been heard at the sites in the Portage Creek subwatershed.

Two species, the wood frog and Cope's gray tree frog, were heard in the 1990's but not during the 2001 sampling events. Five species were heard in all years of the study:

• Western Chorus Frog
• Spring Peeper
• American Toad
• Gray Tree Frog
• Green Frog

Of those five species heard each year, the number of calls heard in 2001 is greater than those heard in 1996 for three species:

• American Toad
• Gray Tree Frog
• Green Frog

The Spring Peeper was the most abundant species in all years of sampling.

Frog and toad survey data for the entire state of Michigan can be found by clicking here.

Source: Data courtesy of Lori Sargent, Natural Heritage Program, Wildlife Division, Michigan Department of Natural Resources. February 4, 2002.