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Tiny T. RexCollared Lizards In Kansas

Travis W. TaggartAssociate Curator of Herpetology

Sternberg Museum of Natural History

photos by Mike Blair

FFew events are more impressionablethan a youngster’s first encounter withan Eastern collared lizard. Fortunately,

it can happen to most Kansas youth just ashort drive from their homes. I first cameface-to-face with this lizard along thespillway at Bourbon State Fishing Lake insoutheastern Kansas. As a wide-eyed secondgrader, it was easy for me to imagine thegreen reptiles as miniature T. rex, and todream that I had entered another place — ina miniature scene from the Cretaceous of pre-historic time. They were sitting alertly onevery other large rock. As I approached theywould scamper for cover, occasionally liftingtheir front feet and running on their hindlimbs with their tails elevated off the ground.I would just sit motionless — and watch —and wonder, how was I going to catch one?

Like miniature dinosaurs, Eastern

collared lizards are fascinating

reptiles common in

parts of Kansas.

My father led these excur-sions, and each trip only height-ened my curiosity andappreciation for these unusuallizards with the over-sizedheads. Usually, we were outfishing, but we always foundtime to flip a few rocks andchase some lizards. Lookingback, it must have been enter-taining for him; after demon-strating to me how to catch thereptiles, he would turn me loose,while he kept an eye on me froma distance. Eastern collared

lizards are agile and fast, whichmakes them hard to catch overthe relatively open terrain theynaturally inhabit. More impor-tant to me at the time, they bithard, and they held on — andchewed. But I was young, andthe lizards were really never inany great danger of me cap-turing them.

The Eastern collared lizard isa wary predator, scaly and greenwith long claws, a strong tail,

and a large powerful head forgripping and crushing live prey.These reptiles have excellenteyesight and spend much timeresting on perches above the sur-rounding landscape. When ameal is spotted, it is run downand swallowed whole.Occasionally, a moth is snatchedout of the air as it flies near. Thelizard then quickly returns to itsrock. Collared lizards aren’tpicky eaters; the only tworequirements for a potentialmeal are that it is moving and

that it fits into the lizard’smouth. These small dinosaurlook-alikes eat small mammals,all manner of arthropods, otherlizards and snakes, and evensmall birds. In turn, they arepreyed upon by birds, mam-mals, bigger collared lizards, andsnakes. Unlike most other lizardspecies in Kansas, the Easterncollared lizard is unable toregenerate its tail once lost.When cornered, this reptile will

stand sideways, high on its legs,and curl its tail around to thefront, then gape open its mouth,displaying a patch of black pig-ment inside. It may attempt toleap towards an aggressor andoccasionally give a short hiss.It’s almost comical to see such abluff from a creature so small butin the lizard’s day-to-day life, itmust be a beneficial behavior.

The Kansas distribution ofEastern collared lizards is inter-esting. Collared lizards are notevenly distributed across thestate. Instead, they are typicallyfound only in the vicinity of suit-able rock outcrops. In one rareexception, a population of theselizards has made use of mammalburrows in loess bluffs in a por-tion of Meade County that lacksany outcroppings. Generally, thelarger and flatter the rocks, thebetter the lizards like an area.Collared Lizards are abundantthroughout the Flint Hills, theSmoky Hills along the SmokyHill, Saline, and Solomon rivers,and in the Red Hills of southcen-tral and southwestern Kansas.They are also known from sev-eral locations in the easternquarter of the state, south of theKansas River; however thesepopulations are typically iso-lated and local. A single popula-tion is known from the vicinityof Bear Creek in Stanton Countyalong the Colorado border and iscorroborated by other suchlizards found in adjacent south-eastern Colorado. These reptilesare absent from the more recentgeologic deposits such as allu-vium, dune sand, loess, andglacial drift which is the pre-dominant land cover in much ofthe western half of the state andin the northeast.

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The rock outcroppings, shown here in Barber County, are prime collared lizard

habitat. The larger and flatter the rocks, the better lizards seem to like them.

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Where they occur, youcan see Eastern collaredlizards perched atop largerocks during sunny warmdays from late March toearly November, when theair temperature reaches 70-90 degrees. Like all otherreptiles in the state, Easterncollared lizards are cold-blooded and derive theenergy necessary for theirmetabolic processes fromthe external environment.There is fierce competitionamong male Eastern col-lared lizards for the bestrocks to occupy. This com-petition is generally non-violent, consisting ofhead-bobs and push-ups; how-ever, when two lizards similar insize meet, one may aggressivelychase the other away.

Collared lizards are activeduring the day, and at nightretire to burrows or tunnels nearor under their basking rockswhere they sleep. In late

October, they retire deep intothese same burrows to avoidfreezing temperatures and awaitthe arrival of warmer tempera-tures in late March to April.

The Eastern collared lizardgets its common name from thetwo black rings on the neck,which resemble a collar. There

are several speciesof collared lizardsfound throughoutthe southwestUnited States andMexico, but oursoccupies the easternmost range. TheEastern collaredlizard reaches thenorthern limits ofits range in Kansas.It can also be foundin southeasternColorado ands o u t h w e s t e r nMissouri, and souththrough north-western Arkansas,Oklahoma, easternNew Mexico, and

central Texas. It is the statelizard of Oklahoma, where it iscommonly referred to as theMountain Boomer. The name isa misnomer of sorts, and coinedon the misconception that theselizards were capable of pro-ducing loud, far-reaching calls.The only vocalization they arecapable of is a nearly inaudiblehiss when threatened.

Their scales are small andgranular, giving a very fine,smooth appearance. They shedtheir skin, not en masse assnakes do, nor cell-by-cell as wedo, but rather in rough-edged,dime-sized patches. They arelarge lizards, reaching nearly 14inches in length, with the headwell differentiated from theneck. In most types of reptiles, itis often difficult to determine thegender of a specific individual.Eastern collared lizards are anotable exception, especially asadults. The males are green, andduring the spring courtshipperiod, they are bright green toblue and often have large yellow

The sexes are easily distinguished in collared lizards. Males are more colorful,

usually green, especially during the spring breeding season when they may be

bright green to blue.

The name-sake bars are clearly visible. Collared

lizards can grow to a length of 14 inches and

while fleeing, they may lift their front legs and

run only on their hind legs.

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heads and occasionally narrowyellowish bands or spots alongthe sides. In contrast, the femalesare drab brown to gray withflecks of tan and often irregulartan bands along the sides.During late spring and earlysummer, mature females haveseveral bright orange or redbands on the neck and alongeach side of their bodies, butotherwise retain their normalcoloration. Both sexes have anirregular pattern of widely-spaced small white dots on thetop of their body and tail.

Eastern collared lizards can bedifficult to capture. During coolweather, they can be foundsnuggled up under rocks in arelatively torpid state wherethey are slow to move, and thuseasy to pick up. However,during warm weather or sunnydays, you’ll often need help –one person to lift a rock andanother to see which nearbyrock the quarry darted under.This process is repeated overand over (and typically involveslifting the same rocks severaltimes) until someone makes a

successful lunge and pins thelizard against the ground. Atthis point, the collectors areeither thankful for the leathergloves they’re wearing, orwishing that they would havethought to wear them.

The collared lizard is non-ven-omous, and its teeth are actuallyquite small and of little conse-quence in its bite. The discomfortcomes from the force of the bite, atrait evolved to crush grasshop-pers but effective at pinchingunprotected fingers as well. Oncecontrolled in hand, they can beeasily and safely carried bygrasping them around their bodyjust behind the head. The lizardcan then be placed temporarily ina pillow case or other cloth bagfor further examination orrelease. Actually, the only realdanger associated with huntingand chasing collared lizardscomes from: 1) rolling the largerocks over your own feet, 2)diving for a lizard in prickly-pearcactus, or 3) lifting a really bigrock only to find that the spaceunderneath it is home to a nest ofhornets. All of this makes forgreat fun amidst some unusuallanguage and much screaming.

Another catch method thatmay be used while the animalsare active is noosing withmonofilament line tied to a longthin pole. This techniquerequires some practice for thecollector to become proficient. Ifyou maintain that critical dis-tance between yourself and thelizard, the reptile will allow youto slip a loop of fishing lineattached to a long pole aroundits neck. In using this method,care must be taken to secure thelizards as quickly as possible toprevent them from thrashingaround, although I have yet to

Easily seen during the day basking on rocks and feeding on any creature that

ventures close, collared lizards retreat to dens under rocks during the night.

The map above shows Eastern collared lizard locations. Populations of these

lizards appear to be healthy and stable where suitable habitat exists.

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see one injured by using thistechnique. Back in the late 1960s,well-known herpetologist JoeCollins perfected this technique.He used an extra-long col-lapsible fishing pole with a smallmonofilament noose on the end.Collins and a companion woulddrive a car slowly along a ruralroad bordered with large rocks.After driving near a collaredlizard (they are often accus-tomed to cars), he simplyextended the pole out over thelizard, noosed the lizard, andjerked the pole until it collapsedback into the car. He wouldunhook the lizard, drop it in acontainer, and continue to cruisefor lizards. Collins was leg-endary for his preference to col-lect specimens while riding incomfort whenever possible.

For most collectors, Easterncollared lizards make terriblelong-term pets. Keeping themhappy and healthy requireslarge enclosures and the abilityto monitor and adjust nutrition,lighting, temperature, andhumidity. Individual lizards can,

however, be kept quite satisfac-torily in a terrarium for a shortperiod of time, allowing obser-vation. They are unlikely to eatfor very long in captivity andshould be released where cap-tured after a couple of days.

Eastern collared lizards areknown to live 10-15 years in cap-tivity when properly cared for.

In nature, they would seldomreach that age. Male lizards areusually sexually mature by theirfirst spring, although theyseldom get to mate due to thecompetition from older andlarger males. Males typicallyreach their maximum size by agethree, while smaller females willcontinue to grow slowly overtheir entire lives.

Courtship and mating takesplace in the spring followingemergence from winter dor-mancy. Depending on body size,the female will lay 1-13 round,leathery-shelled white eggs inburrows or tunnels under rocksduring May and June. During awarm spring, it is not uncommonfor a female to lay two clutches ofeggs up to one month apart.While incubating, the nest is vig-orously defended by the female.The eggs hatch approximately 10weeks later in August andSeptember. The 3- to 4-inch youngresemble miniature adults andimmediately fend for themselves.

Other than natural predators,

Young collared lizards immediately fend for themselves after hatching.

These newly hatched collareds were oblivious to the sharp cactus spines.

In May or June, the female will lay 1-13 leathery eggs in burrows under

the rocks. Eggs hatch in about 10 weeks. A female may lay two clutches

during a warm spring.

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Eastern collared lizards have few threatsin Kansas. Due to differences in generalhabitat preference and use, interactionswith humans are relatively infrequentwhen compared to many other reptilespecies in state. There seems to be littleevidence to suggest that populations havechanged much in number or geographicsize over the past 50 years.

While perhaps not as ornate andprickly as the Texas horned lizard, nor asunusual as the Western slender glasslizard, the sight of an Eastern collaredlizard on its perch is every bit as impres-sive. The next time you’re in a rocky area,take time to scan the tops of the largestboulders for this large lizard. Try toapproach one and marvel as it aggres-sively bobs its head up and down in anattempt to scare you away. See just howclose you can get to it, before it beats ahasty retreat beneath the boulder orinside a crevice. It’s the closest thing to aT. rex that will ever run from you.

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Want to see ‘em?Great public places to observe Eastern collared lizards on sunnydays are Big Basin Prairie Preserve (Clark County), Bourbon StateFishing Lake and Wildlife Area, Chase State Fishing Lake andWildlife Area, Clark Wildlife Area, Crawford State Park, CowleyState Fishing Lake, Geary State Fishing Lake and Wildlife Area,Hollister Wildlife Area, Kanopolis State Park, Meade State Parkand Wildlife Area, Montgomery State Fishing Lake, and WilsonWildlife Area.

Want to learn more?Resources for further information on Eastern collared lizards inKansas: Amphibians and Reptiles of Kansas, 3rd Edition. Joseph T. andSuzanne L. Collins, 1991. University of Kansas Press, Lawrence;Kansas Herpetofaunal Atlas, http://www.fhsu.edu/ksfauna/herps;Kansas Herpetological Society. http://www.ku.edu/~khs; TheCenter for North American Herpetology, http://www.cnah.org

Fun FactThe largest Eastern collared lizard from Kansas was a 302 mm (12inches) male collected by Charles J. Cole on August 27, 1963, inChase County.

Collared Lizard Research In KansasEva Horne, assistant director of Konza Prairie, and instructor andresearch assistant for the Division of Biology at K-State, is studyingthe territorial behavior of reptiles at Konza Prairie.