74 Joseph C. Mitchell and Michael C. Odom 



was opened on the date of collection, and the rest were placed in a 

 closed plastic container with a 3:1 mixture of top soil and vermiculite. 

 The soil was kept moist during the incubation period so that the 

 relative humidity was maintained at nearly 100%. Incubation temperatures 

 varied from 25 to 30° C. During the course of incubation, 12 of the 

 66 eggs died and were discarded; 54 eggs survived. Hatching 

 commenced on 20 August (78 days incubation), and the last egg 

 pipped on 24 August (82 days). Hatchlings showed considerable 

 variation in development, with larger individuals bearing a small 

 yolk sac and smaller individuals bearing a large, cumbersome yolk 

 sac. Of the 54 hatchlings, four failed to survive through yolk sac 

 absorption. The remaining turtles began exogenous feeding as their 

 yolk sac diminished, taking a diet of chopped nightcrawlers and 

 miscellaneous live aquatic macroinvertebrates collected from 

 ponds. The surviving juvenile turtles were released the following 

 spring. 



A documented clutch size of 67 eggs is 12 larger than the 

 largest reported for Virginia (Mitchell 1994). Incorporation of the 

 large clutch size reported here yields a new state average of 29.9 ± 

 16.6 (range = 7-67). The maximum known clutch size for Virginia 

 populations lies between those known for northern populations 

 (83: Quebec (Bleakney 1957); 73: New York and Wisconsin (Yntema 

 1970); 109: Nebraska (Packard et al. 1990)) and southern populations 

 (43: North Carolina (Brown 1992); 21: Florida (Punzo 1975)). 



Reports of average clutch sizes for snapping turtles in different 

 geographic areas based on small sample sizes should be used with 

 caution. Such averages will almost always change with additional 

 data. 



ACKNOWLEDGMENTS— Viz thank Kurt A. Buhlmann and John 

 B. Iverson for their comments on the manuscript, and Thomas F. 

 Burnett for assistance in the collection of the adult turtle and 

 maintenance of the eggs and hatchlings. 



LITERATURE CITED 



Ash, R. P. 1951. A preliminary report on the size, egg number, incu- 

 bation period, and hatching in the common snapping turtle, Chelydra 

 serpentina. Virginia Journal of Science 2:312 (abstract). 



Bleakney, S. 1957. A snapping turtle, Chelydra serpentina serpentina, 

 containing eighty-three eggs. Copeia 1957:143. 



