Beaded lizards

23maart2011
Source: artis.nl, waza.org
The beaded lizards is named for the bead-like bumps on its skin, which are reinforced scales (osteoderms) that make the skin into armouring to protect the reptile against enemies such as coyotes, birds of prey and humans.
There is yet another weapon in the beaded lizard’s arsenal: they are venomous like their closest relative, the Gila monster. The venom glands are located in the lower jaw; when the beaded lizard bites, venom flows into the victim through grooves in the lower teeth. The lizard keeps hold of its victim, chewing to spread the poison into the flesh.

Beaded lizards (Heloderma horridum exasperatum) are found in the wild in the forests, semi-deserts and grasslands of western Mexico. These reptiles can grow to be 80 cm long and can weigh up to four kilograms; the males are somewhat larger and heavier than the females. The skin is black with yellow to pink spots. The animals can reach at least 30 years of age. They don’t become active until dusk, remaining in their holes during the day. They hibernate from November to April.

In the wild, beaded lizards eat small mammals, birds, reptiles, frogs, eggs and insects. In zoos, they are fed day-old chicks, mice and (for mature animals) rats.

Three beaded lizards have hatched at Artis zoo (Amsterdam, Netherlands); these are thought to be the first in Europe to have been bred in-house.