Gila Monster (Heloderma suspectum) Familie: Gila Monster & Beaded Lizard (Helodermatidae) Orden: Squamates or Scaly Reptiles (Squamata).

Size:  Usually 25-35 cm. Occasionally up to 61 cm. Largest specimens tend to come from the eastern part of the range. Distribution:  SW. USA (Utah, Nevada, California, Arizona, New Mexico), NW. Mexico (Sinaloa, Sonora). 0-1500 m above sea level. Habitat:  Mainly desert and mesquite grassland with sandy soils, but also pine-oak forest, tropical decidous forest, and thorn forest. It is usually found in rocky foothills and avoids open flats. Primarily terrestrial, but occasionally climbs trees, as high as 5-7 m. Hides under rocks and stones or in burrows, either dug by other animals or by itself. Food:  Small birds and their youngs and eggs, rodents, other lizards. When food is abundant, the animal's tail will become bulky with stored fat, which later will serve as an energy reserve during times when food is scarce. Reproduction:  Mates throughout summer. 1-8 eggs are laid in July-August, during fall or winter. Activity and behaviour:  Primarily nocturnal, but may be seen out on warm days in winter or spring. Sex differences:  Sex identification is difficult from external features. Ultrasound scanning may give the clearest indication. Alternatively, observations of behaviour (including mating behaviour) can give the answer. Variation:  Two different subspecies (races) of the gila monster are recognized. They differ slightly from each other in various characters, including colour pattern. Status:  Legally protected throughout its range and by international trade restrictions (CITES). Notes:  In spite of being venomous, the gila monster is not aggressive towards humans and may appear sluggish and docile. Nevertheless, it should be treated with respect, as it is capable of reacting very quickly if it feels threatened or provoked. Bites are rarely fatal to humans, but extremely painful. The venom is produced in some glands lying along the lower jaw. It is not injected by means of specialized poison fangs, as it is the case in venomous snakes, but flows into the wound inflicted by the gila monster's sharp teeth. The animal keeps holding on the victim or prey with its jaws and "chews", so that the venom will enter more effectively. References: Behler, John L. & King, F. Wayne. 1979. The Audobon Society field guide to North American reptiles and amphibians. Alfred A. Knopf, New York. 744 pp. Campbell, Jonathan A. & Lamar, William W. 1989. The venomous reptiles of Latin America. Cornell University Press, Ithaka, New York. 425 pp. Stebbins, R.C. 1985. A field guide to western reptiles and amphibians. Houghton Mifflin Company, Boston. 336 pp. Text & layout: Rune Midtgaard

Gallery Home Of the world's nearly 5000 different lizard species, only two are venomous, the Gila Monster and its near relative, the Beaded Lizard. © Rune Midtgaard.