Return to Conservation Biology Research on Reptiles
Linck, M.H. 1987. Blanding's turtle study at Kellogg-Weaver Dunes. Final report submitted to the Minnesota Department of Natural Resources. Unpaged.
The purpose of this study was to scan and sample wetland areas in Wabasha County for Emydoidea blandingii turtles, mark individuals migrating to and from nesting grounds, and to locate turtles in the nesting process and check locations of raided nests (mammalian predators). A total of 8 field trips were made to the Kellogg-Weaver Dunes area during May and June of 1987, and 6 field trips were made to the Weaver Dunes area during August and September of 1987. Local residents were consulted and it appeared that the peak of hatchling migration for 1987, most likely occurred between August 31 and September 6, 1987. Hatchlings were picked up, checked for shell abnormalities, presence of caruncle, and yolk sac, and then released.
55 adult turtles were located at the Kellogg-Weaver Dunes. 15 of the 55 were found to be previously marked by Pappas and Brecke. An additional 12 adult turtles were observed on land but were not disturbed. 7 of these 12 were determined to be nesting. The other 5 appeared to be resting in suitable nesting areas. 57 hatchlings were found in the Weaver Dunes area. 20 of those hatchlings were collected on August 31, 1987.
Burning done prior to May 10 and after October 1 should not interfere with either adult or hatchling turtle movements to and from nesting areas. A May 10 date would make allowance for the three other species of turtles observed in the dunes area (Chelydra serpentina, Chrysemys picta, and Graptemys geographica). While extensive pine growth would obviously destroy open sandy areas preferred for nesting, some of the pine appears beneficial in providing protection from heat. Although Blandings prefer nesting at dusk or later, they often rest during their day-time searches for nest sites. Residents have commented that with the newer homes built on Prichard Lake, vehicle traffic has substantially increased, thereby increasing roadkilled turtles. Sport dog trials held in early June in the McCarthy Lake area bring additional traffic at a time when many Blandings are out and crossing WCR 84. The possibility of moving the trials to an earlier date or different location should be considered. Turtle crossing signs have been suggested, especially between the TNC driveway and E. Kelly's farm. 21 of 57 hatchlings found were killed. In many cases, the hatchlings would have already come 1/2 over dunes only to be killed on the road. Only a small percent of nests come to hatching due to mammalian predation. The road traffic takes a great toll on those nests which do hatch. A drift fence or efforts to transport the hatchlings as they cross the road are two more ideas for this problem.
Continued mark and recapture studies would help to determine if the Blanding's are faithful to specific nesting areas, as well as determining the size of the population. Another emphasis should be on searching for juvenile age classes in an attempt to assess hatchling survival. It would be of great interest to sample the McCarthy Lake area to see what kind of a population of Blanding's are present and whether those turtles also move east to the dunes east of WCR 84.