Animal · United States, Mexico
Gila monster
Heloderma suspectum — the name this animal has in the language scientists everywhere share.
The Gila monster is a heavy black-and-orange desert lizard covered in bead-like scales, and one of the very few lizards with a venomous bite. It moves slowly and spends most of its life underground.
Picture credit: ALAN SCHMIERER (CC0) · Burgers' Zoo (CC BY-SA 4.0) · Wikimedia Commons
Where does the Gila monster live?
Home: Rocky deserts and dry scrub of the American Southwest.
In the wild it lives in these countries: the United States, Mexico.
Conservation status from the IUCN: close to being at risk.
The short profile
Fully grown: up to 56 cm long, tail included. It weighs about 0.7 kilograms. On the menu: meat.
The story behind it
Gila monsters are built for waiting rather than chasing. They spend roughly nineteen days out of twenty in burrows and under rocks, and come out mostly in spring, when eggs are easy to find. A single meal can weigh a third of the lizard itself, and the fat stored in that thick tail keeps it going for weeks. The venom sits in glands in the lower jaw and does not shoot out like a snake's: the lizard has to bite and hold on while the venom runs along grooves in its teeth. A bite hurts badly but is almost never deadly to a healthy adult. One substance in that venom, exendin-4, led doctors to a medicine now used to treat diabetes.
Find it on the globe
Gila monster is there as a tiny animated figure that breathes and looks around. From far away the planet is only a blue ball; detail arrives as you zoom in, and this one appears once you are close enough. Open it on the globe.
It sits at its real coordinates, not near them — the same numbers listed in the facts above. Switch off the layer for this kind of place and it disappears again; the buttons for that are down the right-hand edge.
Questions children ask
Is the Gila monster dangerous to people?
Its bite is venomous and extremely painful, but almost never deadly for a healthy adult. The lizard is slow and shy, and it bites only when someone picks it up or corners it.
Why is it called a Gila monster?
It is named after the Gila River in Arizona, where early naturalists found it. The word monster comes from its size and its grim look, not from its behaviour.
How often does a Gila monster eat?
Rarely. It may eat only a handful of large meals in a year, each up to a third of its own weight, and lives off the fat stored in its thick tail in between.
Where these numbers come from
Every figure on this page was checked against public reference sources before publication. Where sources genuinely disagree, the text says so.
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