174 ARTHUR M. BANTA. 



entirely, and if the disturbance was considerable the males 

 would leave the surface of the water. The renewal of the chorus 

 was then uncertain. It might be renewed soon or not for an 

 hour or two or if the air became cooler in the meantime it might 

 not be heard again that day. The amount of disturbance re- 

 quired to interfere with their activities depended upon the degree 

 of excitement of the chorus, and upon whether or not there had 

 been any previous disturbance. Several times upon my approach 

 to the pond during the breeding season a Cooper's or sharp- 

 shinned hawk flew from a tree immediately over the pond. Few 

 frogs were seen at the surface and these had only their heads 

 protruding and many of them disappeared at the slightest 

 unusual movement in the neighborhood. There seemed good 

 reason to think that the hawk had been feeding upon the frogs, 

 for it was seen there often and each time the frogs were less 

 in evidence than otherwise noted during the breeding season 

 when conditions were at all favorable for their seeking mates. 

 At one time when the writer was at the pond a crow flew over 

 casting a shadow across the pond and the chorus quickly died 

 down and almost stopped but there being no further alarm it 

 came up again at once. The following note was made after 

 a- hawk had been frightened away from the pond when the 

 frogs had been much disturbed and the pond seemed almost 

 destitute of frogs: " Very few frogs visible. 15 minutes later one 

 of the decoys in the bag croaked, a submerged almost choked- 

 off croak. It was followed soon by two or three other croaks 

 from the same place and then one of those in the pond uttered a 

 single croak and, the wave of confidence spreading, in two minutes 

 the chorus was in full swing and the pond where all had been still 

 as death was filled with active croaking tackling frogs." Such 

 a speedy renewal of the chorus seems to indicate excellent per- 

 ception on the part of the submerged males of the first sounds 

 made by the few males at the surface. 



The males remain at the surface at night when the air is not 

 too cool and on one moonlight night the full chorus was observed 

 at 10 P.M. 



The behavior of the female wood frog is usually very different 

 from that of the male. The female remains at the bottom of 



