Skinks
Skinks
North American species of skinks
Skinks are smooth, shiny-scaled lizards in the family Scincidae, most of which occur in tropical and subtropical climates, although a few occur in the temperate zones. Most species of skinks occur in Africa, south and Southeast Asia, and Australia, with relatively few others occurring in Europe and North and South America.
Their body is roughly cylindrical with distinctive overlapping scales on their belly, and a head that ends in a pointed snout. Most skinks have well-developed legs and feet with five toes, but some species are legless slitherers, which can be distinguished from snakes by their shiny, uniform scales, their ear-holes, and the structure of their eyelids.
Skinks are quick, active animals, and most species are difficult to catch. They are also very squirmy and difficult to hold, commonly attempting to bite, and their tail often breaks off easily when they are handled. The broken tail will regenerate from the stump, but not to the original length and coloration.
About one-third of the approximately 1,400 species of skinks are ovoviviparous, meaning the female retains the eggs inside of her body until they hatch, so that “live” young are born. The other species of skinks are viviparous-that is, they lay eggs.
Skinks are terrestrial animals, hunting during the day for insects and other small arthropods, while the larger species also hunt and eat small mammals and birds. During the night skinks typically hide under rocks or logs, in crevices of various kinds, or in a burrow that the animal digs in soft substrates. Most species occur in habitats that are reasonably moist and skinks are not found in arid environments.
North American species of skinks
Most species of skinks inNorth America are in the genus Eumeces. The five-lined skink (Eumeces fascia-tus ) is widespread in the eastern United States and southern Ontario in open forests, cutovers, and other exposed habitats having an abundance of damp ground debris. This species has a distinctive pattern of five lines running down its back.
The broad-headed skink (E. laticeps ) also occurs in the eastern United States. During the breeding season, the males of both of these species develop a bright red head. Other males react aggressively to this color, through ritualized displays, and sometimes by fighting. The females skinks, however, do not have red heads and are not treated this way.
The Great Plains skink (E. obsoletus ) occurs in prairies of the west, while the four-lined skink (E. tetragrammus ) occurs in Texas and Mexico.
The females of most species of Eumeces skinks brood their eggs and recently hatched young. One female Great Plains skink was observed curled around her clutch of 19 eggs under loose treebark. The mother skink cleaned and moistened her eggs by licking them, turned them frequently to facilitate even incubation and proper development, helped the young to hatch when they were ready to do so, and brooded the young and licked them clean. This degree of parental care is unusual among reptiles.
The ground skink (Leiolopisma laterale ) occurs throughout the southeastern United States, hiding in plant litter on the forest floor, and sometimes in suburban gardens. The sand skink (Neoseps reynoldsi ) is a rare species that only occurs in two isolated areas in Florida.
Other species of skinks
One of the most unusual species of skinks is the Australian stump-tailed skink (Tiliqua rugosa ), one of very few species that does not have a long, pointed tail. The stubby tail of this species looks remarkably like the head, and the animal may have to be examined closely to tell which way it is pointing. This species is sometimes called the pine-cone lizard, because of its unusually large body scales. Unlike most skinks, this lizard is mainly herbivorous.
The giant skink (Corucia zebrata ) of the Solomons and nearby islands in the Pacific Ocean is another unusual species of skink. This tropical forest lizard spends much of its time climbing in trees. It has a prehensile tail and strong, clawed feet to aid with its climbing. The giant skink can attain a body length of 26 in (65 cm), and is the largest species in its family.
The snake skinks are various species in the genus Ophiomorus, which either have greatly reduced limbs, or are completely legless. Species of snake skinks occur in southwestern Asia and the Middle East.
The recently extinct skink, Didosaurus mauritia-nus, was the world’s largest species of skink, occurring on Mauritius and nearby islands in the Indian Ocean. This skink was rendered extinct by mammalian predators that humans introduced to its island habitats, particularly rats, mongooses, and pigs. Mauritius was also the home of the world’s most famous extinct animal, the turkey-sized flightless bird known as the dodo (Raphus cucullatus ).
Resources
BOOKS
Pianka, Eric, and Laurie J. Vitt. Lizards: Windows to the Evolution of Diversity. Berkeley: University of California Press, 2003.
Zug, George R., Laurie J. Vitt, and Janalee P. Caldwell. Herpetology: An Introductory Biology of Amphibians and Reptiles. 2nd ed. New York: Academic Press, 2001.
Bill Freedman
Skinks
Skinks
Skinks are smooth, shiny-scaled lizards in the family Scincidae, most of which occur in tropical and subtropical climates, although a few occur in the temperate zones. Most species of skinks occur in Africa , South and Southeast Asia , and Australia , with relatively few others occurring in Europe and North and South America .
Their body is roughly cylindrical with distinctive overlapping scales on their belly, and a head that ends in a pointed snout. Most skinks have well-developed legs and feet with five toes, but some species are legless slitherers, which can be distinguished from snakes by their shiny, uniform scales, their ear-holes, and the structure of their eyelids.
Skinks are quick, active animals, and most species are difficult to catch. They are also very squirmy and difficult to hold, commonly attempting to bite, and their tail often breaks off easily when they are handled. The broken tail will regenerate from the stump, but not to the original length and coloration.
About one-third of the more than 800 species of skinks are ovoviviparous , meaning the female retains the eggs inside of her body until they hatch, so that "live" young are born. The other species of skinks are viviparous-that is, they lay eggs.
Skinks are terrestrial animals, hunting during the day for insects and other small arthropods , while the larger species also hunt and eat small mammals and birds . During the night skinks typically hide under rocks or logs, in crevices of various kinds, or in a burrow that the animal digs in soft substrates. Most species occur in habitats that are reasonably moist and skinks are not found in arid environments.
North American species of skinks
Most species of skinks in North America are in the genus Eumeces. The five-lined skink (Eumeces fasciatus) is widespread in the eastern United States and southern Ontario in open forests , cutovers, and other exposed habitats having an abundance of damp ground debris. This species has a distinctive pattern of five lines running down its back.
The broad-headed skink (E. laticeps) also occurs in the eastern United States. During the breeding season, the males of both of these species develop a bright red head. Other males react aggressively to this color , through ritualized displays, and sometimes by fighting. The females skinks, however, do not have red heads and are not treated this way.
The great plains skink (E. obsoletus) occurs in prairies of the west, while the four-lined skink (E. tetragrammus) occurs in Texas and Mexico.
The females of most species of Eumeces skinks brood their eggs and recently hatched young. One female great plains skink was observed curled around her clutch of 19 eggs under loose tree bark . The mother skink cleaned and moistened her eggs by licking them, turned them frequently to facilitate even incubation and proper development, helped the young to hatch when they were ready to do so, and brooded the young and licked them clean. This degree of parental care is unusual among reptiles .
The ground skink (Leiolopisma laterale) occurs throughout the southeastern United States, hiding in plant litter on the forest floor, and sometimes in suburban gardens. The sand skink (Neoseps reynoldsi) is a rare species that only occurs in two isolated areas in Florida.
Other species of skinks
One of the most unusual species of skinks is the Australian stump-tailed skink (Tiliqua rugosa), one of very few species that does not have a long, pointed tail. The stubby tail of this species looks remarkably like the head, and the animal may have to be examined closely to tell which way it is pointing. This species is sometimes called the pine-cone lizard, because of its unusually large body scales. Unlike most skinks, this lizard is mainly herbivorous.
The giant skink (Corucia zebrata) of the Solomons and nearby islands in the Pacific Ocean is another unusual species of skink. This tropical forest lizard spends much of its time climbing in trees. It has a prehensile tail and strong, clawed feet to aid with its clamberings. The giant skink can attain a body length of 26 in (65 cm), and is the largest species in its family.
The snake skinks are various species in the genus Ophiomorus, which either have greatly reduced limbs, or are completely legless. Species of snake skinks occur in southwestern Asia and the Middle East.
The recently extinct skink, Didosaurus mauritianus, was the world's largest species of skink, occurring on Mauritius and nearby islands in the Indian Ocean. This skink was rendered extinct by mammalian predators that humans introduced to its island habitats, particularly rats , mongooses , and pigs . Mauritius was also the home of the world's most famous extinct animal, the turkey-sized flightless bird known as the dodo (Raphus cucullatus).
Resources
books
Grzimek, B., ed. Grzimek's Encyclopedia of Animals. London: McGraw Hill, 1990.
Bill Freedman