At a length of up to
two feet (0.6 meters) and a maximum weight
exceeding five pounds (2.3 kilograms), the
venomous Gila monster (pronounced HEE-luh) is the
largest lizard native to the United States.
Easily identified by
their black bodies marked with dramatic patterns
of pink, orange, or yellow, Gilas are found in the
Mojave, Sonoran, and Chihuahuan deserts of the
southwestern U.S. and northwestern Mexico. They
take their name from Arizona's Gila River basin,
where they were first discovered.
The Gila monster is
one of only a handful of venomous lizards in the
world. Others include the similar-looking Mexican
beaded lizards, as well as iguanas and monitor
lizards. Its venom is a fairly mild neurotoxin.
And though a Gila bite is extremely painful, none
has resulted in a reported human death. Unlike
snakes, which inject venom, Gilas latch onto
victims and chew to allow neurotoxins to move
through grooves in their teeth and into the open
Gilas are lethargic
creatures that feed primarily on eggs raided from
nests and newborn mammals. They may spend more
than 95 percent of their lives in underground
burrows, emerging only to feed and occasionally to
bask in the desert sun. They can store fat in
their oversized tails and are able to go months
Gila populations are
shrinking due primarily to human encroachment, and
they are considered a threatened species.