Covered in pink and black bead-like scales, the Gila monster (Heloderma suspectum) is the largest lizard native to the United States. It is one of only two venomous lizards found in North America, along with Mexican beaded lizard. However, they are slow-moving and sluggish by nature so pose little threat to humans.
These reptiles live in the deserts of southwestern North America, where they hunt insects and ground-dwelling vertebrates, including small mammals. Their name comes from Arizona’s Gila River basin – the area where they were first discovered. Gila monsters spend 90% of their time underground in burrows or rocky shelters, allowing them to stay cool in the desert heat.
Their oversized tails can be used to store large amounts of fat, letting Gilas to go for months without a meal. Unbelievably, these lizards may only consume as few as three big meals a year, and still maintain good health.
The Gila monster’s venom is a neurotoxin which would be extremely painful to humans, but there have been no reported deaths from being bitten by a Gila monster. Unusually for reptiles, the Gila monster does not inject its venom, instead it latches onto its victim and chews to allow neurotoxins to move through the grooves in their teeth and into the newly created wound. The most fascinating aspect of their venom is the proteins that it contains. A synthetic version of the protein exendin-4, derived from the Gila monster’s saliva, is used for the management of type 2 diabetes. Surprisingly, this protein has proved to be a highly effective treatment for diabetes, emphasising the ever-amazing wonders of wildlife.
Hennessy, K., Wiggins, V. (2014) Animal Encyclopedia: The Definitive Visual Guide. 2nd edn. London. Dorling Kindersley.