Plestiodon tetragrammus

The four-lined skink (Plestiodon tetragrammus) is a species of lizard, which is endemic to North America. It is a medium-sized member of the Plestiodon skinks.

Taxonomy
At least two subspecies are recognized, including the nominotypical subspecies:
 * Long-lined skink, P. t. tetragrammus Baird, 1859
 * Short-lined skink, P. t. brevilineatus (Cope, 1880)

Some herpetologists also consider the mountain skink (Plestiodon callicephalus) to be a subspecies of Plestiodon tetragrammus under the name P. t. callicephalus. Others, however, prefer to treat the mountain skink as a distinct species because its range is geographically distinct and there are morphological differences.

Description
The two subspecies can be distinguished by their color and their stripes. The long-lined skink is gray to light brown in color and has light stripes from the eyes extending to beyond its forelegs, whereas the short-lined skink is darker in color and has stripes that end before the forelegs.

Juveniles of both subspecies have &mdash; like many Plestiodon &mdash; a blue tail; this color fades with age.

Adults reach a maximum SVL (Snout-Vent-Length) of some 7.5 cm (about 3 inches), and a TL (total length) of about 18 cm.

Geographic range
Plestiodon tetragrammus occurs in northern Mexico and along the Mexican Gulf coast and in western and central Texas.

Habitat
Both subspecies live in lightly wooded areas, with the short-lined skink having a preference for rocky areas, whereas the long-lined skink is also found in grasslands.

Reproduction
The female lays about 5 to 12 eggs once a year, which she broods. Males develop orange (short-lined skink) to red (long-lined skink) coloration of the head during the breeding season.