THE BREEDING BEHAVIOUR OF THE FROG l6l 



one exception, which was possibly a mistake, I saw no female a second 

 night, and in the 1934 paper I concluded that the females arc not in 

 amplcxus for more than one night. This was premature, and in the 

 1935 paper I pointed out that there are conditions under which the 

 females remain in amplexus for days during the pre-spawning 

 season. 



The numbers of frogs in this pond remained similar until nearly the 

 end of the season. Since a good many tagged males were not seen again, 

 the inference is that there is some coming and going among the males. 

 One or two were very regular in their attendance, for example A5; 

 others absented themselves for long periods, for example A4 and A9. 



The difference between the sexes is not quite adequately expressed by 

 the usual statement that the males arrive first, followed by the females. 

 Most of the males do arrive before most of the females but the chief 

 difference is that the females arrive, or at least enter the spawning site 

 a tew on each night, but large numbers of males are already there, and 

 a smaller stream of males continues to arrive throughout the season. 



Voices 



The normal croak of the male is a harsh sound without much carry- 

 ing power. A breeding chorus of about a thousand males in Large 

 Totteridge Pond was sometimes inaudible fifty yards from the pond. 

 The warning croak used when one male touches another is a quicker 

 sound, about two or four to a second, somewhat resembling the grunt 

 of a pig. There is a good deal of variation in both notes at different 

 times and in different frogs, and the two voices are not so sharply 

 distinguished from one another as, for example, in the toads, Bufo bufo 

 or Bomhina variegata (Savage, 1934, 1932). 



The term "Call-note" for the ordinary croak of this species is not 

 very appropriate. In other Anura, for example B. bufo, the male takes 

 up a more or less definite station from which he calls. The note could 

 clearly function for attracting the female, although whether it does so 

 is uncertain. In R. temporaria a male does not stay still but jostles 

 continually in a crowd with his croaking companions. The croak is 

 communal, and while perhaps effective over a short range in attracting 

 a female to the spawning site, cannot function for attracting a female 

 to any particular male. Ponds with very few frogs in them may be 

 quite silent, and vigorous croaking is characteristic of a crowd of frogs 

 and not of individuals. Noble and Aronson (194-) l^^ve pointed out 



