CONSERVATION AND THE COMMON SNAPPING TURTLE (CHELYDRA SERPENTINA) ALONG THE 
ILLINOIS RIVER.

John K. Tucker1 and James T. Lamer2 
1 Great Rivers Field Station, Illinois Natural History Survey, 8450 Montclaire 
Ave, Brighton, IL 62012. 2 Department of Biological Sciences, Western Illinois 
University, 1 University Circle, Macomb, IL 61455.

The common snapping turtle (Chelydra serpentina) is harvested as a food item in 
much of its range in the United States.  Harvest of snapping turtles from roads 
has received little attention.  These turtles, which are nearly all females 
going to nest or returning from nesting, are usually destined for the cooking 
pot.  Removing nesting females has to have a large impact on populations.  
Recently, we initiated a trapping program to examine the effect of incidental 
take from roads on snapping turtles in west-central Illinois.  Our goal was to 
develop data sufficient to use in protecting the snapping turtle as a renewable 
resource.  We chose three backwater lakes along the Illinois River as study 
sites (see Tucker, 2001).  Two lakes (Lower Stump Lake and Gilbert Lake in 
Jersey County, Illinois) extend along side Illinois Route 100, a heavily 
traveled road.  One lake (Swan Lake in Calhoun County, Illinois) is surrounded 
by the Two Rivers National Wildlife refuge.  We predicted that the sites most 
exposed to human traffic would have male dominated sex ratios compared to the 
more protected site.  Our findings support this hypothesis. Males made up more 
than 80% of the catch at the two Jersey County lakes whereas they made up  53% 
of the catch at Swan Lake.  These results are important because the practice of 
removing snapping turtles from roads is widespread and our data suggest that the 
impact is considerable.

Keywords: Illinois River, common snapping turtle, male dominated sex ratios, 
harvest pressure, conservation, resource management.