TURTLES 



CHAPTER 13 



The United States is rich in numbers and species of turtles, which are 

 widely distributed and of varied habitats. Only on the west coast do we find 

 any reduction of the turtle fauna, where but one species, Clemmys marmorata, 

 is native. The scarcity of turtles in this region corresponds with conditions 

 in Europe, where numbers and species are much fewer than over most of our 

 country. In several other ecological respects the life of the west coast resembles 

 that of Europe. The two regions also share a genus of crayfish which is not 

 found east of the Rocky Mountain area. 



Turtles, although all built on the same general plan, show considerable 

 adaptation to their environment. As a generality, it may be said that the 

 flatter the shell, the more aquatic the turtle. The extreme is reached in the 

 soft-shelled turtles of the genus Amyda, which have a height of about two 

 inches associated with a diameter of more than a foot. The amphibious turtles, 

 such as the spotted and the wood turtles, are of intermediate proportions, while 

 those largely confined to land, as the box and the gopher turtles, have very 

 high, arched shells. 



Soft-shelled, mud and musk turtles are almost never seen on land. Con- 

 sequently they are unknown to most people, although the name ''mud turtle", 

 which should be restricted to the genus Kinosternon, is often applied indis- 

 criminately to almost any turtle. The snapping turtle, Chelydra serpentina, 

 is almost entirely aquatic, especially as it matures. It has become so specialized 

 for devouring its food under water that it is unable to swallow, unless it can 

 submerge its head. These turtles are largely carnivorous. The snapper, because 

 of its large size, great abundance, and clever methods of ambushing and stalking 

 its prey, works great destruction to fish, frogs and waterfowl entering its ter- 

 ritory. There are several cases on record where dogs have been dragged by 

 snappers under the surface of the water, there to be drowned and ripped to 

 pieces by the powerful claws. 



The majority of turtles are amphibious, almost equally at home on land 

 or in the water. Here we find the turtles so commonly seen basking on a log 

 projecting from the water. These promptly prove, as one approaches, their 

 right to the popular names of sliders and scooters. The painted turtles and 

 the Pseudemys group usually prefer quiet ponds with plenty of water-lilies 

 and submerged vegetation. The painted turtle includes m its omnivorous diet 

 the seed pods of the water-lilies, some of the hard-coated seeds of which pass 

 unharmed through the digestive tract to fall and develop into more turtle pas- 

 ture. The geographic or map turtle and Lesueur's or the ridgeback turtle prefer 

 more open water, while the spotted and wood turtles like small ponds and 



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