San Esteban Island chuckwalla  (Sauromalus varius)

This plump lizard can grow up to 60 centimetres, making it by far the largest of the chuckwallas (Sauromalus), and similar in size to its large iguana relatives (4) (5). This is a prime example of ‘insular gigantism', the tendency of small mainland animals to increase in size once established on an island due to fewer natural predators (2) (4). The chuckwalla's grainy, sand-coloured skin is splotched with shadowy grey blotches over the entire body, providing almost perfect camouflage against potential predators in its rocky habitat. Sadly, this lizard's large size, rather small head, loose, gathered folds of skin, and long, thick, blunt tail means that it has sometimes been mistaken for the poisonous gila monster, and persecuted as such (6).