HABITAT AND RANGE:
Gila Monsters range from southwestern Utah, southern Nevada and adjacent San Bernadino County in California, southeastward through west and south Arizona and southwestern New Mexico. It ranges into Mexico through Sonora to northwestern Sinaloa. They live in arid areas that contain scattered cacti, shrubs, mesquite and grasses, along with rocky slopes, arroyos and canyon bottoms.
PHYSICAL CHARACTERISTICS:
Gila Monsters can grow up to 3 feet long and weigh between 2 and 5 pounds. Its scales have the appearance of intricately laid beads in colors of blue, silver, pink, yellow or orange. These beads are actually small bony plates that form scales, known as osteoderms. The Gila Monster has a thick tail that is used to store fat, which it can live off of if food is scarce. The tail cannot grow back if it is broken, unlike many other lizards. They have large forefeet and sharp claws, which is used to dig. Its thick black tongue is used to smell.
ADAPTATIONS:
The Gila Monster spends about 95% of its
time underground in mammal burrows or
rocky shelters. They are most active in
the morning during the dry season; later
in the summer it is mostly active on
warm nights or after a thunderstorm.
They maintain a body temperature of
about 86 degree Fahrenheit. Although
Gila Monsters do not have great speed,
they have relatively high endurance and
aerobic ability.
Gila Monsters are one of the only
lizards who are venomous. The venom is
produced in modified salivary glands in
their lower jaws. They lack the ability
to forcibly inject the poison; they
propel it from the gland to the tooth by
chewing. The teeth are loosely anchored,
which allows them to be broken off and
replaced through the lizard’s life. The
Gila Monster mostly uses its venom as a
defense mechanism and not to capture
prey.
DIET:
The primary diet of the Gila Monster
consists of bird and reptile eggs. They
will, however, occasionally eat small
birds, mammals, frogs, lizards, insects
and carrion. In the wild, they will only
eat 5 to 10 times a year. When they do
feed, they may eat up to 1/3 of its body
mass. Gila Monsters use their extremely
acute sense of smell to locate eggs,
even if buried 6 inches under the sand.
They can crush their prey to death if it
is too large or eaten alive if small.
REPRODUCTION AND DEVELOPMENT:
Gila Monsters reach sexual maturity
between 3 and 5 years old. Mating takes
place in May and June. The male will
initiate courtship by flicking his
tongue, in search of the female scent.
To reject a male suitor, the female will
bite him and crawl away. Copulation can
last from 15 minutes to 2 ½ hours. The
female lays the clutch of 2 to 12 eggs
in July or August; she will bury them
under 5 inches of sand. Incubation lasts
4 ½ months. Hatchlings are about 6
inches long and can bite and inject
venom upon hatching.
STATUS IN WILD:
Many factors effect the population of
the Gila Monsters, such as pet trade,
habitat destruction and urban sprawl. As
a result, they are protected by Arizona
and Nevada state law. In 1952, they were
the first venomous animal to be given
legal protection. They are listed as
Near Threatened.
