Common collared lizard

Common Collared Lizard
Collared Lizard in Albuquerque, NM
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Suborder:	Iguania
Family:	Crotaphytidae
Genus:	Crotaphytus
Species:	C. collaris
Binomial name
Crotaphytus collaris (Say, 1823)

The Oklahoma Collared Lizard or Collared Lizard, Crotaphytus collaris, is a North American lizard that can be up to a foot (30 cm) long in total length (including the tail), with a large head and powerful jaws. They are well known for the ability to run on their hind legs, looking like small dinosaurs. The collared lizard is the "state reptile" of the United States state of Oklahoma, where it is known as the Mountain Boomer. The name "collared lizard" comes from the lizards' distinct coloration, which includes bands of black aroud the neck and shoulders that look like a collar. It is a member of the collared lizard family.

These reptiles are often tamed and kept as pets. When born in captivity, they are quite docile and tolerant of interaction with humans. They are very active and predatory lizards, requiring a large amount of space to run. They prefer high temperatures, up to 105-110°F (40-43°C) at their basking spot and 80°F (26°C) elsewhere in their habitat during the day. Some collared lizards eat small amounts of fruit or vegetables, but most prefer a diet of insects. They will also consume vertebrate prey, including small mammals and other lizards. Like many reptiles, in captivity they must be provided a diet supplemented with extra calcium and a light source with a UVB radiation to reduce the risk of bone disorders.

Collared Lizard in Zion National Park, Utah

The origin of the name "mountain boomer" is not clear, but it may date back to settlers travelling west during the Gold Rush. One theory is that settlers mistook the sound of wind in canyons for the call of an animal in an area where the collared lizard was abundant. In reality, collared lizards are silent.

These animals are possibly best known for their predatory nature. Like many other lizards, including the frilled lizard and basilisk, collared lizards can run on their hind legs, and are relatively fast sprinters. Record speeds have been around 16 miles/hour (26 km/h), much slower than the world record for lizards (21.5 miles/h or 34.6 km/h) attained by the larger-bodied Costa Rica spiny-tailed iguana (Ctenosaura similis).

Recently, collared lizards in the wild have been the subject of a number of studies of sexual selection.

References

Bonine, K. E., and T. Garland, Jr. 1999. Sprint performance of phrynosomatid lizards, measured on a high-speed treadmill, correlates with hindlimb length. Journal of Zoology, London 248:255-265. PDF

Garland, T., Jr. 1984. Physiological correlates of locomotory performance in a lizard: an allometric approach. Am. J. Physiol. 247 (Regulatory Integrative Comp. Physiol. 16):R806-R815. PDF

Husak, J. F., and S. F. Fox. 2006. Field use of maximal sprint speed by collared lizards (Crotaphytus collaris): compensation and sexual selection. Evolution 60:1888-1895.

Husak, J. F., Fox, S. F, Lovern, M. B., and Van Den Bussche, R. A. 2006. Faster lizards sire more offspring: sexual selection on whole-animal performance. Evolution 60:2122-2130.

Lappin, A. K., Y. Brandt, J. F. Husak, J. M. Macedonia, and D. J. Kemp. 2005. Gaping displays reveal and amplify a mechanically based index of weapon performance. American Naturalist 168:100-113.

Snyder, R. C. 1962. Adaptations for bipedal locomotion of lizards. Am. Zool. 2:191-203.

Gallery

• El Malpais National Monument, New Mexico
  El Malpais National Monument, New Mexico
• 
  Bristol Zoo, England
• Petrified Forest National Park, Arizona
  Petrified Forest National Park, Arizona
• 
  Elena Gallegos Picnic Area, Albuquerque, New Mexico
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  Pair of Crotaphytus collaris