C J AlbrecW 



Female western chorus frog (left) approacfiing a male. 



items per day, or 4,800 prey per year per frog. Thus, a 

 small population of 1 ,000 frogs would consume 4.8 mil- 

 lion arthropods per year. 



The western chorus frog, Pseudacris triseriata 

 triscriata, is a 0.75-1.5-inch frog with three broad 

 stripes on its back and a light line along the upper jaw. 

 This abundant frog is heard calling in large choruses in 

 March and April; the call of a single frog is best de- 

 scribed as the sound made by a running a finger slowly 

 over a comb's teeth. As settlers moved into the mid- 

 western grasslands during the 1800s, chorusing chorus 

 frogs provided the musical background for man's altera- 

 tion of the prairie. Today, chorus frogs will use almost 

 any shallow body of water for reproduction — cattail 

 marshes, flooded farm fields, suburban drainage ditch- 

 es, even water-filled tire tracks. Small clusters of eggs 

 m gelatinous masses float in the water or are attached 

 to submerged vegetation. Chorus frogs rarely climb and 

 are relatively poor swimmers. After reproducing, the 

 adults spread out into surrounding upland habitats, 

 sometimes where it is quite dry, to feed. 



The western chorus has an interesting relative in 

 central Illinois, the Illinois chorus frog, Pseudacris 

 streckeri illinoiensis, a frog unknown to science until 

 1950. This is a subterranean treefrog, a true paradox, 

 that burrows into the sandy soil of Illinois sand prairies 

 and feeds while underground. Males may chorus while 



the ground is snow covered, in March and April. 



The spring peeper, Pseudacris crucifer crucifer, has 

 been long considered a true treefrog and placed in the 

 genus Hyla. However, it has recently been reassigned 

 to the chorus frog genus, Pseudacris. The spring peeper 

 can be readily identified by the large X on its back. Like 



Spring peeper, Pseudacris crucifer crucifer. Note characteristic 

 Xon back. 



the toads and chorus frogs, it is an explosive breeder; 

 large choruses sing day and night for a day or two in late 

 March or early April, until most of the eggs in the pop- 

 ulation have been laid and fertilized. The male's call is 

 a single, clear, high, piping note. This call is used to 



Eggs of spring peeper attached to submerged plant stem. After Wright. 



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