Interactions between Sonoran Desert Toads (Incilius alvarius) and mammalian predators at the Northern Jaguar Reserve, Sonora, Mexico

The Sonoran Desert Toad (Incilius alvarius) is a large (< 191 snout-vent length) anuran with relatively smooth skin, large, kidney-shaped parotoid glands, white glands or tubercles under the parotoid glands, and large, lumpy glands on the dorsal and lateral aspect of the limbs. When threatened, individuals are known to in ate their bodies and orient the parotoid glands toward the threat while making a hissing sound (Hanson and Vial 1956). The parotoid and other glands of this species secrete potent toxins that include indolealkylamines and bufogenins (Erspamer et al. 1967, Cei et al. 1968, McGill and Brindley 1978), as well as 5-MeO-DMT— a powerful hallucinogen that comprises 15% of the dry weight of the parotoid and tibial glands (Weil and Davis 1994). Musgrave and Cochran (1930) reported a fox terrier that bit into a Sonoran Desert Toad and died within 2-3 minutes, and a German Shepherd who touched its nose to a Sonoran Desert Toad and walked no more than 100 feet before its front legs buckled under it. The dog was paralyzed but later recovered. The hallucinogen 5-MeO-DMT has made glandular toxins from the Sonoran Desert Toad popular among recreational drug users (Most 1984), but it is also gaining prominence in alternative medicine, particularly for treating addictions.