Cross Timbers Wildlife News
Jim Dillard, Wildlife Biologist, Texas Parks & Wildlife Department, Mineral Wells
My first experience with a mountain boomer was during a trip I made many years ago to Lipan in northwestern Hood County with my Texas A&M roommate Rippetoe. We’d been assigned a project in our herpetology class to collect and catalog specimens of all the reptile and amphibian species we could find in that area. Rip grew up around there and knew all the back roads and likely snake, lizard and toad-frog hangouts. He told me about seeing a mountain boomer last summer while he was hunting arrowheads down along a rocky creek just north of town. Rip only told me what he thought I needed to know at the time about things and then let me find out the rest later on my own. I didn’t know a mountain boomer from a boomerang, but off we went anyway to catch one.
It wasn’t long before a flash of green caught my eye as a long-tailed lizard bailed off the top of a big rock to the shadowy confines of a nearby rock ledge. “Mountain boomer,” Rip yelled, and the race was on. We soon discovered that not only were mountain boomers fleet afoot, they’d even get up on their hind legs and shift into high gear when you got close, sorta like a miniature T-Rex. Rip, being built closer to the ground than me and quicker than greased lightning, outmaneuvered the speedster and gracefully scooped him up with an old fish dip net. He then handed him over to me to put in one his mom’s pillowcases we’d borrowed from her linen closet to hold our catch.
That experience made a lasting impression on me, including the one left in the loose skin between my thumb and forefinger on my right hand where the mountain boomer latched onto me. It held on for dear life until Rip slowly and with considerable giggling pried him loose. “No, I didn’t know they’d bite – why didn’t you tell me?” “Well, I thought everybody knew mountain boomers bite and won’t let go until it thunders. Maybe next time you’ll be more careful when you pick one up (tee-hee-hee).”
Collared Lizards (Crotaphytus collaris) or “mountain boomers” are found throughout the western two-thirds of Texas. There are three subspecies with the Eastern Collared Lizard (C. c. collaris) calling the Cross Timbers home. In the Trans Pecos Region of far west Texas, you’ll find the Western (C. c. baileyi) and Chihuahuan (C. c. fuscus) subspecies. The Reticulated Collared Lizard (C. reticulatus) can only be found in far south Texas. Crotaphytus from the Greek word krotaphos means “temple”, phton means “creature” or “animal” and collaris collar or loosely translated, a collared creature with temples.
Folks up in Okla-bygosh-homa were so enamored with mountain boomers that in 1969 they named them their state lizard (“Mountain Boomer, Boomer Sooner” – isn’t that some school song?). The mountain boomer moniker is also associated with “hillbilly folks”, red squirrels and in the Pacific Northwest, a beaver-like rodent. Contrary to folklore, they’re not poisonous and don’t boom in the mountains (or valleys for that matter).
The ground color of male Eastern Collared Lizards is typically green or it may be bathed with various shades of yellow, tan or pale brown. White spots adorn their back and long tail and six yellowish or reddish bands run across their back. There are two distinct black stripes on their neck that may be interrupted at the nape. During the breeding season, skin coloration may be much brighter. Males have a tan to brown head with a yellowish throat. Their long tails are usually the same color as the body with brown spots or bars. Female boomers are less colorful but may have orange or pink spots on her sides and neck when carrying eggs. Body scales are granular. Unlike many other species of lizards, collared lizards don’t regenerate their tail if it is chomped off by a predator.
At up to 14 inches in length, they’re our largest lizard species. Males are larger than females. Their broad head and stocky build makes them formidable predators for their preferred insect prey. They’ll eat just about anything smaller than they are that moves. Larger insects make up the bulk of their diet which they crush with a powerful bite at the head. Grasshoppers, spiders, moths and beetles are no match for a hungry mountain boomer. They’re also known to eat small lizards and snakes and chew on fingers of unsuspecting wildlife biologists. Snakes, hawks and roadrunners eat them.
They’re heliothermic and prefer rocky country where they can hunt for food, watch for and escape predators and bask on warm rocks to thermoregulate their body temperature. When rock temperatures get too hot, they’ll hot-foot into the shade to cool off. When pressed or pursued, they may run bipedal on their hind legs for short distances, even lifting their tail off the ground to reduce drag. Although not well adapted for climbing, they’re good jumpers. If you can get one to open wide and say “ahhh”, you’ll see the inside of their mouth is black. During winter months, mountain boomers move underground and overwinter in burrows.
Male mountain boomers are very territorial and detest intrusion by other boomers in the vicinity. They’ll go through a series of head-bobbing and push-up displays to intimidate interlopers and hopefully win the admiration of a passing lucky lady lizard. Collared lizards are oviparous, so about 20 days after mating, females lay 4-8 eggs in loose sand or in tunnels under rocks or boulders. Eggs hatch in two to three months during midsummer. More than one clutch a year is possible. “Baby-boomers” (I just couldn’t resist) are about three inches long when born and scurry off soon after hatching to find their own sunny rock and fend for themselves.
To me, the mountain boomer is a fitting icon for this hard scrabble land called the Cross Timbers where only the toughest plants and most indomitable animals endure through good years and bad. I just hope the rock-haulers don’t carry off all the mountain boomer sunning rocks from this land to build mansions to the sky in the metroplex. Until next time, I’ll see you down the road and God Bless America!