Wood Frog Life History 



33 



Fig. 1. Known Alabama localities for Rana sylvatica determined during this 

 study. Open circles represent breeding localities; inset shows position in the state 

 of counties from which R. sylvatica is recorded. 



Adult Characteristics 



Snout-vent lengths of adult male wood frogs in Alabama averaged 

 50.0 mm (SD = 5.5, N = 20), and adult females averaged 60.0 mm (SD = 

 3.16, N = 18). These values are smaller than those given by Martof and 

 Humphries (1959) for wood frogs in northern Georgia and western 

 North Carolina (males: x = 54.8 mm; females: x = 66.8 mm). Berven 

 (1982a) discovered size differences along an altitudinal gradient from 

 Maryland (lowland populations) to western Virginia (montane popula- 

 tions). Mountain males and females were larger (males: x = 55.3 mm; 

 females: x = 64.4 mm) than individuals from lowland populations 

 (males: x = 41.7 mm; females: "x = 47.7 mm). Because Berven hypothe- 

 sized that selection acted primarily on egg size and that selection for 



