Blotched Water Snake Swallowing Prey
Nerodia erythrogaster transversa

June 3, 2004 -- Temple, Texas

by Jerry Cates

Thanks to J.S., Temple, Texas, for sending in the photos shown on this page

This is a particularly ugly snake, performing what appears to be a singularly ugly act. It is in the process of swallowing a meal, most likely a cane toad (Bufo marinus), its favorite prey. The cane toad is an introduced species, though it lives naturally in far south Texas. Except for the forages of this snake and several other snake species (notably the eastern hognose snake) the cane toad would quickly become a serious nuisance. When this toad was introduced into the cane fields of Australia to eat the scarab beetles there, it soon took to other pursuits. Bee-keepers, for example, had to raise their hives to keep the toads from eating all their bees. 

The irregular outline of the toad can be seen in the photo below. This toad, not easily swallowed, requires the use of specialized anatomical structures in the snake's throat and mouth to deflate its body and draw it into the esophagus. The toxins in the toad's body, particularly in the parotid glands in its neck, present the snake's system with a challenge that a lesser organism would not survive (dogs mouthing such toads have sometimes died from the act).

Ugliness, therefore, is not always a vice. The blotched water snake performs a valuable service, though, as with the manufacture of sausage and the mechanics of diplomacy, its work is best done out of the sight of pedestrians.