Common Collard Lizard, Crotaphytus collaris
Common Collard Lizard, Crotaphytus collaris, Male. Lizard photographed in rural Fruita, Colorado, August 2013. Length: 25 cm (10 inches). Collection, photograph and identification courtesy of Dr. Jake Turin, Albuquerque, New Mexico.
The Common Collard Lizard, Crotaphytus collaris, is a member of the Crotaphytidae Family of Collard Lizards. The Crotaphytidae Family consists of two genera and twelve species. There are nine species in the Crotaphytus Genus. There are five subspecies: Black-spotted Collared Lizard, Crotaphytus collaris, the Chihuahuan Collared Lizard, Crotaphytus collaris fuscus, the Eastern Collard Lizard, Crotaphytus collaris collaris, the Western Collard Lizard, Crotaphytus collaris baileyi, and the Yellow-headed Collard Lizard, Crotaphytus collaris auriceps. They are also known as the Collard Lizard, the Eastern Collard Lizard, the Mountain Boomer, the Oklahoma Collard Lizard and the Yellow-headed Collard Lizard and in Mexico as Cachorón de Collar.
Common Collard Lizards have elongated bodies and are moderate in size ranging from 20 cm (7.9 inches) and 36 cm (14 inches) in length. They have a large, blocky head, long limbs and a long tail. They are distinguished by two black collars around its neck. Both sexes have white bellies. Their color varies from tan or gray to bright aquamarine and yellow. They are sexually dimorphic with the adult males being more vivid and colorful than the females. The males are also larger with larger more muscular heads than the females. The males head dimensions play a key role in determining dominance, territoriality, fitness, as well as mating success. Male Common Collard Lizards have a blue-green body, a yellow-brown head, yellow stripes on the tail and back and yellow-orange throats. The colorations can vary amongst individuals which is attributed to social organizations or habitat. Females have a light brown body and head. When breeding the females under a rapid color change, in which the faint orange spots develop on their heads intensify in brightness which gradually fades after she has laid her eggs. The juveniles resemble adult females exhibiting dull body colorations compared to adult males, but have pronounced, dark brown markings that eventually fade as they grow and mature.
The Common Collard Lizard is found in dry, open regions of Mexico occupying different habitats from rocky desert landscapes to grasslands, but they prefer mountainous regions with high environmental temperatures for optimal thermoregulation. They are a diurnal species being active during the day spending most of their time basking on top of elevated rocks or boulders. They are very wary and prefer the rocky areas of these habitats that provides them with shelter from the sun and predators as well as areas with open vegetation. They are true sun-lovers and remain active even during the hottest part of the day. The Common Collard Lizards are obligate lie-in-wait ambush carnivores, that consume large insects, including beetles, cicadas, crickets, grasshoppers, moths, spiders, and small vertebrates (other small lizards and snakes) as their main diet. These diets vary significantly with seasonal changes. In turn they are preyed upon by birds, house cats, coyotes, other lizards, and other carnivorous mammals. They rely on cryptic coloration, rapid flight skills, burrows, and heavy vegetation for defense. They are known for their running abilities and are able to run on their hind legs at speeds of up to 26 kms per hour (16 mph). This behavior is usually observed when trying to escape predators. They do not lose their tail easily and if lost the tail is non-regenerative. The Common Collard Lizard reproduce sexual and oviparous. They are polygamous and highly territorial species with males being more aggressive than the females. The males collect harems via viciously defend their exclusive territories through aggression, patrolling activities, and displays. They have complex social behaviors that have been extensively studied by the scientific community. Reproduction occurs in the early spring and occurs shortly after they emerge from hibernation. It involves an elaborate courtship that has been well documented within the scientific literature. Eggs are laid in a burrow or under a rock about two weeks after copulation. Clutchs sizes are between four to six eggs and require up to three months to hatch. By August, when temperatures are below 12oC (54oF) they begin to hibernate and are seldom seen.
The Common Collard Lizard is a straight-forward identification that cannot be confused with any other species.
The Common Collard Lizard are native to the American Southwest and in Mexico are found in the north from the Eastern Baja Peninsula each to Nuevo León and to the south from Eastern Michoacan to Puebla.
From a conservation perspective the Common Collard Lizard is currently considered to be of Least Concern with a distribution, tolerance of a broad range of habitats, and large population size. No major threats have been identified for this adaptable species. They are utilized by the pet trade at a modest level but are difficult to maintain in captivity.
Synonyms: Agama collaris, Crotaphytus collaris, and Leiosaurus collaris.