TURTLES AND BATRACHIANS OF THE LAKE REGION. 511 



11. Chorophilus feriarum (Baird). 

 Swamp Tree-frog. 



The Swamp Tree-frog is common throughout all parts of the eastern 

 United States where there are ponds, swamps or creeks. Its presence is 

 usually made known by sound rather than by sight, as the frog, though quite 

 noisy, is both shy and inconspicuous and easily ovei'looked. 



At Lake Maxinkuckee this frog is probably common, scattered about in 

 the marshy regions surrounding the lake. It is not often see, however, and 

 only a few e.xamples were secured. One was obtained on Aubeenaubee Creek 

 July 8, 1899, three about the shore of Lake Maxinkuckee July 28, 1900; one 

 in Norris Inlet August 8, 1900, and one in Farrar's pond at the edge of the 

 lake below Farrar's October 8, 1907. 



A few days after the first high-pitched "peep peep" of Pickering's Tree- 

 frog has sounded from the marshes, the announcement of the arrival of spring, 

 the Swamp Tree-frog begins its chorus, and although it is not the first frog 

 to be heard, it is its chorus coming from the woodland ponds and from the 

 creeks and marshes, that announces to the world in general that "the frost is 

 out of the ground." These frogs all seem to wake up at about the same time, 

 so that the very first song is a pretty full chorus. They begin singing first in 

 the pools and ponds surrounding the lake, and only later stray down to the 

 lake shore. In 1901 they were first heard about March 23; at the beginning of 

 their song season they sang only during the warmer parts of bright days. 

 Intermixed with the chorus came at intervals the high piping of H. pickeringii. 



From March 23 to about the middle of April they sang chiefly during the 

 warmer part of the day, the chill of the night quickly silencing them. About 

 April 24 till May 9, they sang chiefly during the evenings and mornings; 

 later on they sang in diminishing numbers and chiefly on moist muggy nights. 

 They were heard singing as late as June 22. The song is a rattle with a rising 

 inflection at the end, or like the scraping of a coarse-toothed comb. 



It was quite difficult at first to catch this frog in the act of singing, as they 

 become immediately silent on one's near approach. On April 5 some were 

 seen singing near Hank's pond. The frogs stuck their heads above the water, 

 expanded the skin under their throat until it looked like a large yellow bubble; 

 this vibrated somewhat, but did not collapse while the frogs were singing. 

 All the frog out of the water was pretty well hidden behind the bubble, so 

 that the animal itself easily escaped detection. Later on they were occasional- 

 ly seen singing in a row at the edge of the pools. A pair were seen mating 

 April 9 over by Hank's pond. In a pond where many were heard singing a 

 number of small bunches of eggs were found which probably belonged to this 

 species. They were placed in an artificial pool and kept under observation 

 but did not hatch. 



The small tadpoles soon develop, and about June, minute frogs of this 

 species can be seen hopping about, leaving the water. 



