18 . FROGS. 



reaches 68 to 75° (certainly 76 to 79°), the appearance of the bull- 

 frogs may be expected, provided the temperature of the water bot- 

 toms is 57 to 64° or averages 64 to 69°. They are the last frogs to 

 appear and come out from May 11 to June 4. They begin to croak 

 about two or three weeks after emergence from hibernation. 



When croaking begins, the males often take certain perches in 

 which they keep a proprietary interest. About one pond the author 

 once located seven such places, each with its possessor, only once 

 finding two in one place. The characteristics of the stands can best 

 be described by presenting the following list of positions occupied by 

 certain frogs in one pond: The first was on a board in water filled 

 with brush; another w^as perched on a log among brush beneath a 

 float of a boathouse; the third was on the bank among some limbs 

 extending into the water; the fourth was by an overturned stump 

 whose roots were partly out of the water and partly submerged ; the 

 fifth was among some driftwood along the shore; the sixth was a 

 stationary float; and the last was at the base of a tree fallen into the 

 pond. At these stands one could have had good success in captur- 

 mg the frogs at night. This habit of maintaining perches obtains 

 more particularly when the species is not especiaUy numerous in a 

 pond or lake. When, however, the numbers of males about a lake 

 are numerous enough to make their night croaking seem a real 

 chorus, and when they are abundant among the fallen logs and brush 

 of the swampy borders of lakes, it is not likely that any one individual 

 holds a favorite site to the exclusion of the others. In such places 

 one can easily take, in an hour or so, 30 or 40 adults with the aid of 

 either flash light or acetylene fight. 



If one wishes to secure them by day he may adopt the device of 

 the familiar red flannel on a hook or ordinary fish bait. At the 

 breeding season one occasionaUy finds them in grassy situations. 

 Here they lie on the surface of the water. One has only to wade 

 among them to capture them by hand. At first they may become 

 frightened, but soon they reappear. Whenever bullfrogs are hard 

 to find or scarce in certain bad seasons let the collector search out a 

 former miU pond whose dam is gone, and in the temporary small 

 ponds remaining he can frequently find the frogs in tlieir circum- 

 scribed quarters. 



The males have the first finger enlarged (PL XII, fig. 4) and enlarged 

 tympana. They begin croaking 15 to 30 days before actual spawning 

 takes place. In some ponds the males are very much in evidence. In 

 one lake, when the bullfrogs were laying freely, as many as 10 males 

 were found within a space of 8 feet. Here among the dead branches 

 of overhanging elderberry bushes (PL XIII, fig. 1) they were hidden 

 because of the dense mat made by the sliiaibs. At this time in midday 

 the author had no difficulty in capturing, by hand, in half an hour, some 

 25 males, while only three or four females were observed. This was in 

 the middle of June. Later in the season the females appear more in 

 evidence. Doubtless these easy captures of a supposecQy shy form 

 were naturaUy due to the fact that it was their breeding season. 

 The author is, however, coming to believe that tliis species is as easy 

 of capture as any other large frog. Even after a bullfrog has left 

 the water's surface one may capture it while it is swimming beneath 

 the water, for it is very slow as compared with some of the other 



