Eastern Collared Lizard
So
named because of the dark lines around its neck, the Eastern
Collared Lizard (Crotaphytus collaris collaris) is probably
better known by Oklahomans as the “mountain boomer.”
A brightly colored specimen, the Eastern Collared Lizard may be
identified by its tan, yellow or green shades, and the small
light spots scattered over its upper body. Females are
yellowish-tan with only faint spots covering the body. Both
possess the dark brown, irregularly shaped “collar,” and adults
of both sexes typically measure 8 - 14 inches in length.
A diurnal species, the Eastern Collared Lizard is especially
active in warm, sunny weather. These lizards prefer an air
temperature of 73° - 93° F, and as such, are active from April
through September, though young lizards may remain active
through October.
Mountain boomers are often observed sunning on rocks and
boulders, yet quickly retreat to the security of a crevice if
approached. If threatened in an open area, it is capable of
running very fast to escape. In such a situation, the lizard may
run on its hind legs with the forward part of the body held
upright. Each lizard defends a home territory by chasing away
other collard lizards when that territory is violated.
As they are cold-blooded reptiles, the Eastern Collared Lizard
must find a burrow to spend the winter months in. Such burrows
are usually found under large rocks, 8 - 12 inches deep. During
their active months, mountain boomers live among limestone,
sandstone or granite glades, and prefer those facing south or
southwest for maximum exposure to sunlight.
A brief courtship and mating season extends from mid-May to
early June. The males court by displaying their brightly colored
throat and body, while prancing around the female. Twenty days
after breeding, the female will lay from 2 - 21 creamy-white
leathery eggs in a burrow beneath a large rock. Hatching 2 - 3
months later, the young will have dark bands with yellowish
crossbars, and average 3 - 4 inches in length.
Eastern Collard Lizards eat a variety of insects including
grasshoppers and beetles, but also eat spiders, small snakes and
lizards. While their diet renders them beneficial to humans,
they are subsequently preyed upon by large snakes, hawks and
roadrunners.
Common throughout the southwestern United States, the mountain
boomer probably received its nickname from settlers who saw the
lizards sunning on rocks, while hearing the barking of a frog.
In reality, the Eastern Collared Lizard is voiceless.