FIELD BOOK OF PONDS AND STREAMS 



Fig. 306. — Head of male leopard frog with his 

 vocal sacs distended. 



larger and larger, as the croak resounds (Fig. 306). When 

 one of them is singing in chorus it repeats the croak four or 

 five times, keeping its sacs distended, suddenly collapsing 

 them as the air is drawn down into the lungs again. Like 

 other frogs, leopards can croak beneath as well as above the 

 water. During the breeding season, they are easily captured, 

 and mating pairs can be collected and kept in jars provided 

 with enough water for the eggs which are likely to be laid 

 there within a few hours. 



Lije history. — The eggs are laid in masses, attached to 

 sticks or grasses, and are commonly found in marshes and cat- 

 tail pools; each egg mass, containing four to five hundred eggs, 

 is only i or 2 inches across when it is first laid, but the jelly 

 soon swells until it is 3 to 5 inches thick. 



In late July and August recently transformed leopard frogs 

 populate the margins of the ponds. They are both shy and 

 agile, and at the least alarm, will leap wildly into the water. 

 They are long-nosed and slender, brown or green, often with- 

 out any spots at all. These young leopard frogs soon join 

 the old ones which have left the water before them and forage 

 with them through the marsh grass, feeding on grasshoppers 

 and leaf insects until October frosts begin, when they go into 

 the streams to hibernate for the winter. 



Economic importance. — The leopard frog is the frog of the 



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