Gila Monster

The Gila (hee-luh) monster is the largest lizard native to the United States at two feet long and 5 pounds. They are found in the Mojave, Sonoran, and Chihuahuan deserts in southwestern U.S and northwestern Mexico. There are two subspecies, the northern and the southern, with slightly different patterned backs.

They are one of the few venomous lizards in the world, and their pattern of black and pink, orange or yellow warns predators of this toxin. This toxin, a neurotoxin, is fairly strong, but they do not release much of it, so although extremely painful, their bites do not induce human death. Gila monsters, unlike snakes, do not inject their venom, instead they bite and chew their victim to allow the toxin to enter the wound. Gila monsters generally hold on tight once they have bitten down to release as much venom into the bite; some have held on for nearly 10 minutes. As all the Gila monster’s prey is pretty defenseless, their venom is most likely to be a defense.

Gila monsters move very slowly and spend most of their time, between 95%-98% of their lives, underground. They come out from their burrows in the spring and fall to feed and mate, but not often: gila monsters store fat in their tails and can go months without eating. They might only eat 3-4 big meals per year. They mostly eat eggs, newborn mammals (such as young rabbits), carrion, and other small prey. They move slowly and will hiss and gape to try and scare predators before they bite, so if left alone they are relatively harmless. However, in the spring male-to-male combat occurs as a result of the mating season. Females lay 2-12 eggs, which will weather the winter below ground and hatch the next spring. They do not take care of their hatchlings, which are basically miniature 6 inch replicas of their parents. These hatchlings may have quite a long life, and in captivity they have been known to live from 20 years to up to 36.