Natural History of the Broadhead Skink

The herpetology College of Charleston class of Spring 2013 went on a field trip to search for herps in their natural habitat on a brisk, but beautiful, cloudless Thursday, marking the end of February. We began our quest to discover and observe various amphibians and reptiles deep within the county park grounds of Caw Caw Nature & History Interpretive Center. Extending beyond the six miles of trails rich in natural, cultural, and historical resources, were remnants of agriculture utilization via rice fields carved out of the cypress swamps that inhabit much of Charleston's herps. After trekking through the wetlands engulfed in vivacious greens and flourishing browns and observing the herps captured within the 30+ traps, I joined a fellow classmate in his search to find another intriguing herp. We diverged from the boardwalk trail deep within the swamp evergreens and began to overturn decaying logs and other decomposing debris. Just as the sun was setting over the horizon and our field trip was nearing an end, we rolled one last log over; buried beneath wet soil with only its bright blue tail exposed was a young Plestiodon (formerly Eumeces) laticeps, more commonly referred to as a broadhead skink. Characterized by smooth, shiny, cycloid scales underlain by osteoderms, this skink proved to have a hard exterior to the body of about 17-20cm in total length and a head-body length of approximately 7-9cm. Although it appeared to be in a relaxed, dormant state, the broadhead skink became very alert and active during our first attempt of capture by hand; after several attempts, the beautiful broadhead was contained within the hands of my classmate.

Distinction between a southeastern five-lined skink (P. inexpectatus), a five-lined skink (P. fasciatus), and a broadhead skink (P. laticeps) requires a closer look. To immediately rule out P. inexpectatus, we analyzed the undersurface of the tail; the five-lined and broadhead have a middle row of scales enlarged, whereas the southeastern five-lined skink has scales of about the same size underneath the tail. To further differentiate between the broadhead and five-lined, we observed the number of labials present along the jawline and the presence or absence of post-labials located behind the eye. The broadhead skink has 5 labials and no large post-labials; in contrast, the five-lined skink has 4 labials and 2 large post-labials located behind each eye. With a pair of sharp eyes and steady hands, we confirmed the identification of the lizard to be none other than a broadhead skink.

 

The broadhead skink is diurnal, foraging actively by day but taking shelter at night and during bad weather and harsh temperatures. This skink is essentially a terrestrial, woodland species, but is also the most arboreal of the Eastern/Central North American skinks. They are extremely energetic and attentive during the day even when they are found under a decaying log. Broadhead skinks are abundant around Charleston, SC and are found all along the eastern coast of the United States from the tip of Florida to the southern part of Pennsylvania, extending to eastern Kansas and Texas. Habitats vary from swamp forests with abundant moisture to vacant urban areas strewn with debris such as decaying logs and decomposing wood piles. Due to their arboreal lifestyle, broadhead skinks make use of hollow trees and tree holes; occasionally, they are spotted high among naked branches of dead and rotted large oak and cypress trees as well as on a residential fence.

 

The broadhead skink my classmate and I captured was early throughout its life history stage and still considered juvenile due to its distinct blue tail; this young skink will not become a sexually mature adult until approximately 21 months of age. It is beyond its hatchling stage because its body color is in the process of transitioning from a bold black to a light brown, and its tail is becoming less distinct in its vibrant blue color and turning gray. Although the seven (sometimes five) yellow/white longitudinal stripes extending from its head down to the beginning of the tail are easily recognized, there is some indication of the pattern becoming less conspicuous. If the broadhead was human, it would be going through puberty, blossoming from a cute, blue-tailed skink to a beautiful, brown adult with faintly visible stripes.

 

When captured, Plestiodon laticeps was still juvenile, and therefore, it was rather difficult to determine its sex. However, when viewing the specimen up-close and personal, I noticed that the head size appeared to be proportional to the body of the skink. Males have noticeably wide jaws that make their heads broader and longer than the head of females of equal body length. In addition to head size, this broadhead skink retained its striped pattern, with the broad, dark band extending backward from the eye and along the side of the body remaining most prominent. Males may demonstrate traces of stripes, but they tend to become entirely uniform brown or olive in coloration. It is also important to note that during mating season, males become known as "red-headed scorpions", resulting from their vibrant orange/red head coloration throughout mid-spring to early summer. Through careful consideration and observation, the broadhead skink caught was identified as a female, waiting to meet her perfect man.

 

After observing the specimen, we released the skink into its natural habitat and back under the original log where it was first discovered. Not only did our class discover and identify many herps on our field trip, but we also made memories that will forever be engraved in our minds. I look forward to many more field trips in our search for amphibians and reptiles throughout the course.

 

 

Google Books:  Amphibians and Reptiles of Georgia; pages 315-316

 

Peterson Field Guides:  Reptiles and Amphibians Eastern/Central North America; pages 263-264