Chester Zoo 

Gila Monster

The Greek translation of the Gila Monster’s scientific name Heloderma means ‘studded skin’ and is due to the fact that Gila Monsters boast an unusual feature that dates back to prehistoric times. Their skin is made up of numerous round, bony scales, which was common in dinosaurs, but is only infrequently seen in reptiles today. They have a striking black and bright pink, intricately patterned skin colour combination, varying according to their two sub-species. The Reticulated Gila Monster (Heloderma s. suspectum) has a haphazard network of lighter markings along its back, while the Banded Gila Monster (Heloderma suspectum cinctum) has a visually distinctive ‘band’ of lighter markings, also on its back.

They are timid creatures, but have a tenacious, venomous bite, used more for defensive purposes than as an aggressive tactic. They are the subject of many unfounded local superstitions usually centred on their poisonous bite, which is often wrongly reported as fatal to people, though to date their have been no reports of any humans having died as a result of a Gila Monster’s bite.

What they eat

Small rodents, birds, eggs of birds and reptiles. Eats large meals infrequently and is capable of consuming up to one third of its body weight. Young ones can consume up to a half their own weight in one meal. Gila Monsters can survive for months without food, having the ability to store fat in their large tails.

How long they live

The longest recorded lifespan is 24 years.

Biology

Gila Monsters often live in vacated burrows dug by other animals, but can also construct their own. They are most active in early morning or late afternoon, but spend much of the day sheltering in their burrow, either away from the harsh desert sun or hibernating over three months in winter. The spring mating season is from April to June, with males wrestling each other for the right to mate a female. Females lay about a dozen eggs in summer, burying them in depressions in the soil where they are left to incubate over winter before hatching the next spring.

Did you know?

Gila Monsters have helped with the treatment of some kinds of diabetes in humans. In 2005 scientists created a drug based on a man-made version of a substance originally found in the saliva of Gila Monsters. The drug has been shown to help prevent the blood sugar levels of diabetics from getting dangerously high.