Five Lined Skink

American five-lined skinks are native to Frederick County. Often seen darting to a hiding place when disturbed, these agile lizards (Plestiodon fasciatus) likes to sunbathe on rock surfaces. As cold-blooded animals, skinks regulate their body temperatures by alternately sunning and seeking shade.

Adults are about 6 to 9 inches in length, with smooth, shiny scales. They have five light-colored or gold lengthwise stripes on a dark body, and males are slightly larger than females. Older males often lose their stripes and have dark brown or black bodies.  Adults develop reddish heads, with males having more brilliant red heads or jaws during the spring mating season. Younger animals and juveniles have blue tails. They are sometimes referred to "blue-tailed skinks,"  but that name is inaccurate for the local species, since another smaller lizard native to Christmas Island is the true blue-tailed skink.

Skinks prefer moist, wooded habitat with nearby cover, including mature hardwood forest areas with lots of leaf litter, downed trees, rocky areas, and dense foliage. Their home ranges are relatively small, about 30-90 feet in diameter. Some studies indicate that skinks roam freely, returning regularly but not always to the same nighttime resting spot. Males are territorial, driving off other adult males, with pheromones playing a part in distinguishing adult males from females and juveniles. 

After mating in spring, female five-lined skinks lay about a dozen half-inch long eggs in May, in a hole under or within a fallen log, or dug in a damp secluded spot. Females guard their eggs until they hatch, one to two months later, in late spring to summer, with the hatch taking longer when temperatures are low. Warmth absorbed by females basking in the sun is brought back to the nest. Several days after hatching, the young lizards leave the nest and are left to fend for themselves. Skinks feed on insects and spiders and may also eat earthworms, slugs and snails. Predators in the wild include foxes, opossums, snakes and hawks.

Many kids, pets, and predators will find that catching a skink by the tail causes the lizard to lose its tail and escape while the would-be captor is occupied with the wriggling decoy tail. The blue color of the tail is thought to help direct the attention of a potential predator towards the tail. The lizard will grow a new tail.

Five-lined skinks are not poisonous or aggressive towards humans. They can, however, bite when handled, although rarely hard enough to break the skin. Skinks are beneficial by helping to control insects and spiders. Research has also shown the five-lined skink possesses a digestive protein that kills the Lyme disease bacterium when it eats a deer tick carrier.

Article by Tom Anderson, FCFB member

Nature Note for 6/26