MATING BEHAVIOR OF THE WOOD FROG. 173 



such that the progress made is relatively small. At the end of 

 the series of swimming movements the hind legs are often vigor- 

 ously extended alternately thus swaying or turning the body from 

 side to side but resulting in very little forward movement. The 

 series of short swimming movements are repeated by the indi- 

 vidual at varying intervals from a few seconds to several minutes. 

 When the activity is at its height few of the males remain in- 

 active for as long as a half minute at a time and the calls from 

 the numerous males make an interesting and peculiar and not 

 unattractive chorus. The swimming movements are associated 

 with seeking a mate. At the height of the chorus the frogs pre- 

 sent a picture of remarkable activity for amphibians, the males 

 swimming about and each attempting to mate with any frog 

 or small moving object it encounters. Any individual which 

 moves within a radius of several feet of another male is likely to 

 be tested by him. The male thus approached sometimes swims 

 away and sometimes actively resists but often pays no attention 

 to the aggressor and the latter turns back, frequently without 

 coming near enough to touch the male, and almost always the 

 aggressor gives up the attack after the very beginning of an 

 attempt to grasp the stranger with the fore legs. Often the one 

 just attacked turns and "tries" the one that has just then given 

 up an attack upon him but with an equally prompt cessation of 

 the attempt. Seldom is an attempt made upon any but a 

 moving individual. Even a female in the midst of a number of 

 males may usually avoid pursuit as long as she remains quiet. 

 On the other hand any small moving object at the surface of the 

 water is most certain to be approached by an eager male. The 

 writer twice observed a male approach a speckled tortoise when 

 the latter thrust its head out of the water. 1 



The mating activities of the male frogs are not very readily 

 interrupted. By moving quite slowly one may ordinarily ap- 

 proach to within a few feet of the active males without disturbing 

 their chorus. When persons passed noisily by on the old grade 

 however the chorus was more or less quieted, often stopped 



1 One suspects Miss Hinckley may have mistaken the mating activities of the 

 males for she says (I.e., p. 88): The "... presence of the females, who were largely 

 outnumbered by the other sex, had evidently aroused a spirit of jealously among 

 them and each frog was intent on driving the others from the place." 



