Guatemalan beaded lizard

Physical features

• Guatemalan beaded lizards have a large, flat head and a cylindrical body with a thick, long tail where they store fat. The tail serves as an energy reserve and may appear thin if the lizard is starved.

• They are sexually dimorphic but it can very difficult to tell male from female. The females can grow to be 29.9 inches and weigh up to 4.4 lbs. The males are slightly larger and they can grow up to 35.4 inches and weigh up to 8.8 lbs.

• Large, hard, bead-like scales cover the top of their body while the underside is covered with softer scales. These "scales" are actually osteoderms, which are tiny bones imbedded in the skin.

• They are mostly black or dark brown with yellow or white spots along the body and bands on the tail.

Diet: Carnivore

• Wild – Small mammals, bird and lizard eggs, nestling birds, and insects.

• Zoo – Quail and chicken eggs and chicks, mice, rats

Reproduction

• The Guatemalan beaded lizard breeding season is in May through August with egg laying typically from October to January.

• Copulation lasts 30-60 minutes and about 2 months later the female will lay 3-13 eggs and deposit them in a burrow modified from a ground dwelling bird or a lizard.

• Incubation takes approximately 6 months at 80F and the female does not stay with the eggs.

• When the eggs hatch, hatchlings can be up to eight inches long and are black and yellow banded.

Interpretive Information

• They swallow their food whole, except for eggs, which are sometimes broken first.

• They survive high temperatures for long periods of time by becoming completely inactive, a behavior known as aestivating, and utilizing the fat reserves in their tail for energy.

• The Guatemalan beaded lizard is one of the few lizards considered to be truly venomous (others being the Gila monster and some monitor lizards like the Komodo dragon). They have specialized teeth in the lower jaw to deliver the venom when they bite.

• Their venom is known to cause severe pain and nausea, but not death. There has never been a well documented case of a human dying from a Guatemalan beaded lizard bite. 

• Their bold black and yellow coloration is believed to serve as a warning to would-be predators.

• Guatemalan beaded lizards may be preyed on by birds and mammals such as coyotes.

Updated July 2024