Scientists Study Snakes Eating Toxic Toads

U.S. scientists found some non-poisonous snakes have devised an unusual method of warding off predators by eating toxic toads.

Although most snakes are born with poisonous bites, a species of Asian snakes borrow a dose of poison by eating toxic toads and recycle the toxins.

Herpetologists Deborah Hutchinson and Alan Savitzky of Old Dominion University in Norfolk, Va., and their colleagues studied the Asian snake Rhabdophis tigrinus and its relationship to a species of toxic toad its eats.

The researchers found the snakes store toxins from the toads they ingest in their neck glands. Then, when under attack, the snakes release the poisons.

Many invertebrates sequester dietary toxins for use in defense but the scientists say vertebrate examples of toxin sequestration are rare.

Sequestration of toxins in a specialized (gland) structure in a vertebrate is a remarkable finding, said William Zamer, deputy director of the National Science Foundation’s division of integrative organismal systems. This finding offers new insights into the complex mechanisms underlying ecological relationships and will lead to important insights about fundamental biological questions.

The study appears in the online issue of the Proceedings of the National Academy of Sciences.