Common Five-lined Skink

Plestiodon fasciatus (Linnaeus, 1758)

common five-lined skink
Common five-lined skink. Johnson Co., IL photo by A.R. Kuhns

Key Characters: Smooth body scales; seven supralabial scales; two postlabial scales.

Similar Species: Broad-headed Skink. See that account for differences. Also see Key to Lizards of Illinois for help with identification.

Subspecies: None recognized.

Description: A medium-sized (up to 20 cm TL) lizard. Color and pattern depend on age and sex. Juvenile and subadult have a dark back with five longitudinal light lines and a blue tail. Adult female is similar but tail is not blue. Adult male loses stripes with age, eventually becoming uniform olive or brown. Jaws of male become swollen and orange to red during breeding.

Habitat: Wooded habitats including dry uplands, floodplains, and hardwood swamps. Also found on abandoned buildings and around trash piles.

Natural History: Mating occurs in May with eggs laid from late June to July. Two to 18 eggs are laid in sawdust piles, under fallen logs, and under leaf litter. Female usually remains with eggs until hatching. Hatchlings range from 6 to 7 cm TL. Arthropods are the main prey. Predators include birds of prey and small mammals.

Distribution Notes: This species is rare north of the southern extent of the Wisconsin glaciation, but recent (2011) specimens are known from extreme SW Cook County, and one specimen was taken in 1996 in McHenry County.  Cope (1900. U.S. Natl. Mus. Rep. for 1898) reported a specimen (USNM 9418) from Lake County, but I have not examined it.

Status: Locally common in the southern third of the state.

Etymology: Plestiodon is derived from the Greek words pleistos meaning “most” and odontos meaning “teeth”. Plestiodon = Toothy Skinks; fasciatus – fascia (Latin) for ‘stripe’ or ‘band’; -atus (Latin) for ‘pertaining to’ or ‘provided with’.

Original Description: Linnaeus, C. 1758. Systema Naturae per Regina tri Naturae secundum Classes, Ordines, Genera, Species, cum Characteribus, Differentiis, Synonymis, Locis. 10th ed.  Salvii, Stockholm. 1:824 pp.

Type Specimen: Not designated.

Type Locality:“Carolina” restricted to Charleston, Charleston County, South Carolina, by Smith & Taylor, 1950

Original Name: Lacerta fasciata Linnaeus, 1758

Nomenclatural History: PlaticepsPfasciatus, and Pinexpectatus were lumped together as one species for much of the early history of herpetology in North America. Taylor (1933. Univ. Kansas Sci. Bull. 20:263-271) finally settled the confusion, but much of the early literature on these three species is muddled. Therefore, other names that could be applicable to Pfasciatus in the older Illinois literature include Linnaeus’ Lacerta quinquelineata and its subsequent generic transfers, Eumeces quinquelineatus, Plestiodon quinquelineatum, and P. laticeps (Schneider, 1801) The genus Plestiodon was resurrected for all North American species north of Mexico to replace Eumeces after evidence showed a lack of support for the monophyly of Eumeces (Brandley, et al., 2005,Systematic Biology. 54 (3): 373-390; Smith, H. 2005. Plestiodon: a replacement name for most members of the genus Eumeces in North America. Journal of Kansas Herpetology. 14: 15-16).