68 ECOLOGY AND LIFE HISTORY OF THE COMMON FROG 



much like to know the reasons for the survival of so many tadpoles, 

 and the effects of the excessive numbers of little frogs on their ultimate 

 fate, but this kind of thing does not usually interest the reporters, who 

 are content to marvel. 



There is no evidence for any large difference in habits between the 

 juvenile frogs and the adults, except at the breeding season. In some 

 other species, there are such differences. For example (Lantz), the 

 young Natterjack Toad, Bufo calamita, is diurnal and runs about even 

 in bright sunshine. Bragg (1940) found young Bufo woodhousii to be 

 diurnal and Martof (1953) found the same o£ Rana clamitans. Young 

 treefrogs, Hyla arborea, were said by Boulenger (1898) to hve in the 

 grass, and I thought this to be an example of a difference in habits 

 between "young and adults until, happening to go into a field of long 

 grass in France, I foimd many young treefrogs there, just as Boulenger 

 had said, in the grass. But when I saw that each was clinging to a 

 grass stem in exactly the same attitude as the adults adopt when on 

 bushes or trees, I realized that the little frogs were not hving, as I had 

 imagined, as if they were R. temporaria, but had merely adapted 

 the habits of their own species by changing the scale. This is probably 

 made necessary in order to avoid the less humid regions of the tree 

 tops, where such small animals would probably dry up during the 

 day. R. temporaria, adult or young, Hves largely in the grass, and has 

 no need to change its habits in this way. 



It is possible that this phase is one of wide dispersal. Adult frogs 

 must make an annual journey to the ponds to breed. For two or three 

 seasons, the young frogs are freed from this necessity, and could in 

 time cross territory with no ponds and thus populate a new area, if at 

 the end they found ponds in time for their maturity. But we really 

 know very little. 



Length of the Juvenile Stage 



Smith (195 1) considers that sexual maturity is generally reached at 

 the age of three, although sometimes a year earher. This is an im- 

 portant point, with a bearing upon the general problem of predation 

 and abundance, but a further discussion of it belongs to the next 

 chapter. 



The shortness of this chapter emphasizes the paucity of the infor- 

 mation. Perhaps there is nothing more to know, but how often in 

 science has such a view been shown to be false ! 



