tAmphibian populations have been declining worldwide, with several documented specie extinctions in the past two decades. Although monitoring population health can presen challenges, surveys of breeding choruses are relatively effective methods for assessing populations and population trends of many frog and toad species. We analyzed data from breeding chorus surveys conducted throughout Illinois from 1986 to 1989. Of the 20 species native to Illinois, 9 were stable or increasing during the survey period whereas the trends for other species were either inconsistent or indicated a decline in population size. To better assess population trends for Illinois frogs, we advocate re establishment and regular monitoring of choruses, and improved training for volunteers who conduct the surveys.
Florey, Justin and Mullin, Stephen J., "A Survey of Anuran Breeding Activity in Illinois, 1986-1989" (2005). Faculty Publications. Paper 108.