204 ] Snakes and Frogs and Their Relatives 



The old theory that a ring is added each year has been dis- 

 proved. Sometimes several molts take place in a year and rings 

 are added; it is also possible for the snake to molt without a 

 new ring being created. This irregularity, not to mention the 

 fact that rings are often broken from the end, makes it impos- 

 sible to reckon a snake's age by the size of its rattle. If a rattle 

 is unbroken, however, you may approximate the animal's age 

 by allowing one year for each two rings. 



WHAT THE RATTLE Is FOR 



Many snakes have the habit of vibrating the tip of the 

 tail when they are excited, but the rattler is the only kind 

 equipped with a "noise-maker." We do not entirely understand 

 the purpose of the rattle. The once general belief that this reptile 

 always rattles before striking is no longer credited. Apparently 

 it does use its rattle, as a rule, to try to frighten enemies dangerous 

 to its own safety. 



As for the theory of "warning" prospective prey, some ob- 

 servers have decided that this snake sounds its rattle to startle 

 birds, rabbits, or other possible victims into momentary in- 

 activity, thus gaining time for a strike. Other people claim that it 

 never rattles before attacking. There are many reports of rattlers 

 that never rattled at any time, and habitually struck without 

 warning. 



KINDS OF RATTLESNAKES 



There are no less than fifteen different species of rattle- 

 snakes in the United States and they live in many localities. The 

 deadly diamond-back of the southeastern states frequents neigh- 

 borhoods where water is plentiful, the timber rattler lives in 

 woodland mountain regions, the prairie rattler haunts the Great 

 Plains of the West; another species is found in desert wastes. 



Rattlers are among the more important kinds of snakes in 

 our country that bear live young. The mother gives her off- 

 spring no care but none is necessary. They are able to fend for 

 themselves immediately, and have been seen eating ten minutes 

 after birth! 



