Beautiful common collared lizard

 

From -  Wikipedia,

By – Vinuri Randhula Silva,

The Common collared lizard (Crotaphytus collaris), also known as Eastern collared lizard among other names, is a North American species of lizard in the family Crotaphytidae.

There are five recognized subspecies. Males can be very colorful, with blue green bodies and yellow orange throats while females have a light brown head and body. Their distinct feature are the two black bands around the neck and shoulders that look like a collar, hence their name the Common collared lizard.

This species can attain 8–15 in (20–38 cm) in total length (including the tail), and they have powerful jaws. One other notable characteristic is their ability to run on their two hind legs. They can sprint at a remarkable speed of up to 24 km per hour and this usually happen in the instance of evading predators.

 As obligate carnivores, they consume insects and small vertebrates as their main diet. While they may occasionally ingest plant materials, it is not preferred. They feed on a variety of large insects, including crickets, grasshoppers, spiders, moths, beetles, and cicadas, along with other small lizards and even snakes. As plants do not provide enough nutrients for constant body weight maintenance, Common collared lizard cannot survive solely on an herbivorous diet. Their stomachs are too small to accommodate the amount of flowers, shrubs, herbs, etc. that would be needed to maintain a constant body weight. Thus, they are considered obligate carnivores, requiring nutrients from arthropods or other small reptiles.

Diet can also vary depending on age, sex, as well as seasonal changes. In the case of younger lizards, they consume the same kinds of foods, specifically insect species, that adults do, but since younger lizards and adults differ in body size and weight, the amount of food intake tends to vary. On the other hand, male and female adults are similar in terms of their sizes and the amounts of food ingested but exhibit drastic differences in the kinds of foods that they eat. From an evolutionary standpoint, these sexual differences in diet may act to reduce intra-species competition for resources, whereby females and males do not need to fight for the same type of food. Moreover, changes in season can drastically affect their diets as well.

The reproductive season starts in mid-March to early April and concludes in mid-July. Females and smaller individuals emerge first from hibernation with males following around two weeks later. Though lizards are considered mature and may breed following their first hibernation, those that are two years and older exhibit greater reproductive success due to their larger size. In late May, courtship occurs between adult males and females. Subsequently, mature females, typically two years and older, produce their first clutches and lay them in a burrow or under a rock about two weeks after copulation. They may then go on to produce second and sometimes even third clutches throughout June until mid-July. The eggs are incubated in a temperature dependent manner, and the incubation period may vary from 50 to 100 days. On average, clutch size can range from 4 to 6 eggs, but larger, older females can produce more. By August, adults begin to hibernate again, and juveniles do the same after hatching. The earliest of the clutches can hatch in mid-July and later ones follow until mid-October. Upon hatching, juveniles are fully developed and behave independently of their parents, as the common collared lizard do not exhibit any parental care in offspring.

Collared lizards are diurnal; they are active during the day, and spend most of their time basking on top of elevated rocks or boulders. As a highly territorial species, they remain hyper-vigilant, scanning for predators or intruders, ready to sprint or fight when necessary. Generally, males are more active than females, as the former engage in more chase, fight, display, and courtship behaviors while the latter exhibit basking and foraging behaviors. The collared lizard in the wild has been the subject of a number of studies of sexual selection; in captivity if two males are placed in the same cage they will fight to the death. Females, on the other hand, do not demonstrate aggressive behaviors as frequently as males, experiencing less intra-species competition with other females.

References

1.     Ferguson, Gary W. (1976). "Color Change and Reproductive Cycling in Female Collared Lizards (Crotaphytus collaris)". Copeia. 1976 (3): 491–494. doi:10.2307/1443364. ISSN 0045-8511. JSTOR 1443364.

2.      Jump up to:^a b Fitch, Henry S.; Tanner, Wilmer W. (1951). "Remarks concerning the Systematics of the Collared Lizard, (Crotaphytus collaris), with a Description of a New Subspecies". Transactions of the Kansas Academy of Science. 54 (4): 548–559. doi:10.2307/3626220. ISSN 0022-8443. JSTOR 3626220.