One of only two venomous lizards in the world (the other is its Mexican cousin). Slow-moving, distinctively beaded, they spend 95% of their lives underground or sheltering in rocks.

Also called: Gila

Native status: Native; only venomous US lizard

§ Quick facts

SizeBody 35–55 cm (14–22 in)
Weight350–700 g (12–25 oz)
LifespanWild 20+ years; captive 30+
OrderSquamata
FamilyHelodermatidae

§ Encyclopedia

The Gila monster is a species of venomous lizard native to the Southwestern United States and the northwestern Mexican state of Sonora. It is a heavy, slow-moving reptile, up to 22 in (56 cm) long, and it is the only venomous lizard native to the United States. Its venomous close relatives, the four beaded lizards inhabit Mexico and Guatemala. The Gila monster is sluggish in nature, so it is not generally dangerous and very rarely poses a real threat to humans. Nonetheless, it has a fearsome reputation and is sometimes killed despite the species being protected by state law in Arizona.

Source: Wikipedia — Gila monster Licensed under CC BY-SA 4.0

§ Identification

Field marks. Stout-bodied lizard with bead-like scales in patterns.

Similar species. Beaded Lizard (Mexican). No other native US venomous lizards.

Voice. Hisses defensively.

§ Diet & behavior

Diet. Eggs, hatchlings, small mammals.

Behavior. Slow-moving, mostly underground. Venom delivered through grooved teeth.

§ Range

Sonoran and Mojave deserts of Arizona, southern Nevada, southwest Utah, and northern Mexico

§ Habitat

Rocky desert foothills, oak-juniper woodland, near desert washes

§ Threats

Habitat loss to housing developments, illegal collection for the pet trade, road mortality, persecution.

§ Conservation status

According to the IUCN Red List, the gila monster is currently classified as Near Threatened.

§ What helps

Never collect or relocate. If you see one, photograph and report to AZ Game & Fish or other state agency. Drive cautiously on desert roads at dusk.

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§ Further reading

§ Sources cited

  • Tucson Herpetological Society
  • Arizona Game and Fish
  • IUCN Red List 2007