Posted by James Van Dyke on April 24, 2002 at 13:17:15:
In Reply to: I don't totally dismiss the idea of a caudal lure....... posted by Rich G. on April 24, 2002 at 09:20:46:
You're also talking about a controlled situation in an artificial habitat as compared to a natural setting. Your proximity to the snake and then releasing a foreign object into its environment are the cause for rattle. All of the pitvipers I work with in my university's lab seem to, more often than not, make defensive rather than predatory strikes on the prey item. Behavioral studies in the wild also show that, when pitvipers do decide to actively hunt rather than ambush, the rattle is never, ever used- probably for fear of scaring prey away. There is no gain for an ambush predator to alert prey to its presence- except for caudal luring. However, the sound a rattle makes combined with its dissimilarity to any possible invert prey would probably scare off more possible prey instead of just piquing their curiosity.
Rattling seems to be best seen as either a warning or a notification that the snake is there before it gets stepped on. Almost all North and South American snakes vibrate their tales when disturbed. One way of thinking says that this is imitation of rattlesnakes while another says that all snakes do it and rattlesnakes just took it one step further. Besides, about the only predators that rattling will not deter are birds and other snakes. Many mammals avoid snakes that rattle loud enough, even when hungry. Notable predators in the Americas, especially coyotes and foxes, have been observed teaching their pups and kits to avoid rattling animals, but eat those that do not.
