34 Mark S. Davis and George W. Folkerts 



increased fecundity would secondarily favor large body size, comments 

 on the size of Alabama R. sylvatica are reserved for the later section on 

 egg size. 



Martof and Humphries (1959) established evidence for a latitudinal 

 gradient in relative leg length in wood frogs and found that the frogs 

 with the longest legs occur in the southern Appalachians. We calculated 

 TFL/SVL ratios for 19 adult males and 19 adult females to determine if 

 this trend was evident in Alabama R. sylvatica. Tibiofibulas of males 

 averaged .602 of the SVL, those of females averaged .625 — a value iden- 

 tical to that obtained by Martof and Humphries (1959) for both sexes. 



Ruibal (1957) reported a latitudinal and altitudinal clinal gradient 

 in snout length for R. pipiens and pointed out evidence for a similar 

 latitudinal gradient in R. sylvatica. Blunt snouts were defined as those 

 with high height /length (H/L) values (> 1.15), pointed snouts as those 

 with low H/L values (~ 1.00). Wood frogs from northern Canada 

 (locality not given) possessed blunter snouts (x = 1.30 mm, R = 1.07 to 

 1.50, N = 14) than those from New York (x = 1.11 mm, R = 1.00 to 1.22, 

 N= 15). 



Snout lengths were measured on Alabama wood frogs to determine 

 if this apparent cline continued. The mean H/L value was found to be 

 0.83 (R = 0.74 to 0.95, N = 37). These results further substantiate the 

 evidence for a clinal increase in snout length southward. Martof and 

 Humphries (1959) and Martof (1970) described Appalachian wood frogs 

 as having blunt snouts, apparently a subjective description for no quan- 

 titative H/L analysis was performed. 



The coloration of adult R. sylvatica in Alabama is typical of the 

 Appalachian phenotype described by Martof and Humphries (1959). A 

 color photograph resembling the Appalachian phenotype may be found 

 in Behler and King (1979, Fig. 216). 



Breeding Ponds, Breeding Associates, and Breeding Season 



All 14 breeding congregations of R. sylvatica found were in shallow 

 (usually < 45 cm), temporary pools in or adjacent to forests. These 

 pools fill with winter rains from December through February. Most 

 were located in semideciduous woods along the flood plains of large 

 streams. Three sites were found in pastures; however, these were bor- 

 dered by semideciduous woods and probably had been wooded in the 

 past. 



Breeding ponds differed in the amount and type of vegetation. 

 Ponds in open (pasture) situations received more sunlight and were gen- 

 erally characterized by vigorous growths of Eleocharis sp., Juncus sp., 

 and Carex spp. Woodland pools generally had fewer rushes and sedges, 

 probably because of reduced sunlight. Peltandra virginica, Sagittaria 



