After this column was published, I belatedly decided to double-check the identification of the skink mentioned here, enlisting the help of the experts from the Virginia Herpetological Society. They determined it was a common five-lined skink, not the southeastern five-lined skink. For more about my adventure in herp identification, see my June 13 column.
For me, one of the best things about summer is seeing the little flashes of bright blue as sleek young skinks skitter along the exterior of the house, searching for prey.
The bright coloration is limited to the lizards’ tails, an evolutionary adaptation that helps the juveniles escape predators, who are distracted by the flashy color and grab the tail – and that’s all they get. The skink, like many lizards, has evolved to have a tail that breaks off easily at a “fracture plane.”
Although it takes time and energy to grow it back, sacrificing it is still better than the entire skink ending up in a predator’s stomach. While it might seem the blue tails would actually attract more predators, it must work or skinks wouldn’t have developed this adaption.
I’ve loved skinks ever since I discovered them as a child. They’re cute, quick and nonaggressive. Although they will bite in self-defense, they’re nonvenomous, and our local species are so small that they do little damage. They are also great predators, devouring lots of small insects and other invertebrates.
It’s been such a cold spring that I’ve yet to see a skink working the exterior of my house, but one did apparently end up inside my landlords’ house. I got a call that they’d rounded up the lizard, which was large for a skink (about 8 inches), and would bring it up for identification.
Before I did a bit of research and carefully examined the reptile, I assumed that it was the common five-lined skink (Plestiodon fasciatus). I also knew it had a very similar-looking cousin, the southeastern five-lined skink (Plestiodon inexpectatus) but, at the time, I thought the latter’s range ended a bit farther south.
In doing some research, I found that Rappahannock County is actually near the northern end of the southeastern species’ range, and a similar species – the broad-headed skink (Plestiodon laticeps) – ranges further north, to southeastern Pennsylvania. Formerly thought to be in the Eumeces genus, as my Peterson field guide “Reptiles and Amphibians – Eastern and Central North America” has them, all three species have recently been reclassified as being in the Plestiodon genus.
The captured skink’s tail was not blue, but that wouldn’t have helped sort out its identity, since it is characteristic only of juvenile Plestiodons. Likely the young get better at predator evasion as they mature, so the advantage of the flashy tail would diminish. In adult five-lined skinks, the tail matches the coloration of the body, which can have black, pale yellow, white and brown stripes – earth tones that blend in better with the lizard’s surrounding environment.
Broad-headed skinks have similar coloration except for mature males, which are olive-colored and, in breeding season, have orange-red heads and swollen jowls, which gives this species its common name. Both five-lined species top out at about 8.5 inches from nose to tail tip, while a mature broad-headed male can measure more than a foot long. With most skink species, the tails make up almost half the length. With the exception of these males, the appearance of the three species are similar, with only subtle variations on their topsides.
The undersides of all three skink species are white, and the key to distinguishing among the species lies there. Only the scales of the southeastern five-lined skink are uniform in size. The other two have a line of broader scales running down the middle, as shown in the Peterson guide and on the Virginia Herpetological Society website (virginiaherpetologicalsociety.com).
So, the trick now was to retrieve the quick, squirming little reptile from the jar my landlords had put it in and flip it over to see the scale pattern underneath. After a few attempts, carefully avoiding grabbing the detachable tail, I finally got my fingers around the body, hooking them over the short legs to control its writhing – a technique I learned as a kid. Carefully turning the skink over, I could clearly see that the pattern of scales was uniform under the tail, so this was a southeastern five-lined skink.
I took a few photos of the scale pattern and, in the process, relaxed my grip a bit. The skink wriggled loose and went skittering up my arm, stopping to take stock of its situation. I took the opportunity to take another couple of quick shots. Then the phone rang, which distracted me, and the skink ran up to my neck and then leaped to the porch, disappearing under it in an instant.
While I had intended to release the skink into the forest edge behind the house, I’m quite glad to have it cruising around the exterior walls of my house. With luck, I’ll get to see the skink again.
- There are 87 genera and 1,280 species of skinks. They are found on many oceanic islands and every continent except Antarctica. Most live in the tropics of Southeast Asia and Indo-Australia. Three genera consisting of 15 species are native to the U.S.
- The tail color of juvenile skinks in the U.S. can range from bright blue to orange, pink or red, depending on the species. Some skinks have lines; others don’t.
- Skinks are diurnal, taking shelter at night, in high temperatures or in bad weather.
- Skinks live in a variety of habitats, but most are terrestrial and prefer moist habitat.
- Terrestrial skinks, such as those in our area, have short legs and clawed toes; those adapted to burrowing have tiny legs or none at all and transparent eyelids.
- Skinks range in size from the tiny Scincella lateralis, the smallest of which are three inches (nose to tail tip), to the Solomon Islands skink (Corucia zebrata), which can reach almost three feet in length.
- While most skink species are carnivorous, the Solomon Islands skink is an herbivore.
- All skinks are egg-layers.