Heloderma suspectum

The Gila monster ranges from the extreme southwestern Utah, southern Nevada, and adjacent San Bernadino County, California, southeastrward through west and south Arizona and southwestern New Mexico. It ranges south into Mexico through Sonora to northwestern Sinaloa. It ranges from sea level to 1,500 meters in altitude. (Ernst, 1992)

The Gila monster can be found in arid areas. These areas usually contain scattered cacti, shrubs, mesquite, and grasses. Rocky slopes, arroyos, and canyon bottoms (mainly those with streams) support populations in Arizona. (Ernst, 1992)

This is one of only two venomous lizard species in the world (the other is the Mexican beaded lizard, Heloderma horridum). Gila monsters are large and stout lizards with a short fat tail (maximum length of 56 centimeters). Their scales are beaded yellow, pink, and black. The broad head, chin, and neck are black, as well as the legs and feet. The black eyes have a round pupil. The ear opening is a narrow oblique or ovoid slit. The limbs of the lizard are stout and have heavy claws. (Ernst, 1992)

Mating, which is usually in May, begins with the male tongue-flicking to seek a females's scent, while rubbing his cloaca on the ground. When a male locates a female, he lies by her and rubs his chin on her back and neck while holding her with his hindlegs. If a female objects to the male, she will try to bite him while crawling out from underneath. If receptive, she raises her tail. The male then moves his tail under hers, bringing their vents into contact. Copulation lasts from 30 minutes to an hour. The female lays her eggs (1-12) in an underground cavity, normally in July or August. Incubation lasts on average about ten months, and the young to hatch and emerge the following May. The process (fertilization through emergence) lasts about a year. (Ernst, 1992)

Few data are available on the population structure and dynamics of the Gila monster because the organisms are extremely difficult to sex. The Gila monster is a diurnal forager. It is referred to as being a "docile reptile." (Ernst, 1992) ( http://www.Pharmacy.Arizona.EDU/centers/poison_center/critters/reptiles/gila monster.|)

The Gila monster's diet consists of a variety of objects: small mammals (young rabbits, mice and squirrels), birds, lizards, and eggs (of birds, lizards, snakes, turtles, and tortoises). The Gila monster has the capability to consume large amounts of food at one time (young can consume 50% of their body weight at a single feeding, adults can consume 35%). This is advantageous in an envirnoment in which finding prey at regular intervals may be difficult. Prey are rarely envenomated, which indicates that venom is used mainly for defense. Prey are detected by olfaction (the sense of smell). The Gila monster, like most snakes, uses its tongue for olfaction. (Ernst, 1992) (Bogert, 1956)

The Gila monster has little economic importance to humans. There is a small market for the hemipenis, which is used as an aphrodisiac. A small "pet" market for the species has also arisen. It is illegal, however, for the Gila monster to be captured or held in the states where it exists. The reptiles can be found in many zoos. (Bogert, 1956) ( http://www.Pharmacy.Arizona.EDU/centers/poison_center/critters/reptiles/gila monster)

The lizard is often killed because it is poisonous. The Gila monster is legally protected in all states in which they are found. (Ernst, 1992) (Bogert, 1956)

The Gila monster lacks the ability to jump, contrary to popular myth (Ernst, 1992)