Cryptic Critter
Walking along the trails of Harmony Hill on spring mornings brings joy and delight in a variety of ways. The warm, morning sun kissing your face as it glimmers in and out of the dappling shade of new leaves on the trees instantly puts a smile on your face. Likewise, the flutter of butterfly wings passing in front of wildflowers and the chorus of birds singing lilting and flute-like songs lifts your spirit until you’re nearly floating above the ground. Catching a glimpse of other woodland creatures not nearly as conspicuous, and not traditionally seen as “beautiful”, will still stop you in your tracks. That is the story of our four-legged reptile friend… a nontraditional looker that is capable of holding your attention and that is deserving of as much appreciation as any resident of our neck-of-the-woods.
In an open area of the forest, the bobbing of a very small head is spotted on the backside of an old Loblolly Pine stump. The movement is fast, and the participant is too preoccupied to notice you just a few meters away. You stop everything and watch a cryptic and camouflaged, spiny lizard as it does pushups and bobs its head up and down. This spring dance is one that Eastern Fence Lizards have done for millennia, and this morning is a continuation of a natural urge to establish territory and to attract a mate to reproduce. And, as in many places, it is a dance we are able to enjoy here at Harmony Hill.
As one of the most common lizards in South Carolina, Eastern Fence Lizards (Sceloporus undulatus) can be found anywhere open forests and areas where meadows meet wood lines. Easily identified by scales that are keeled, or appearing to be rough and almost spiky, this species is tough to mistaken for any other lizard in South Carolina. Keeled scales appear rough because they have a center ridge that usually extends the full length of the scale, giving it that diagnostic rough and spiny appearance.
They prefer drier areas and overwhelmingly prefer places where they can climb to bask, such as fenceposts! (Hence, the common name, Fence Lizard!) One thing is for sure, they love to climb and are our most tree-loving lizard here. Their arboreal nature can be seen as they bask in the warmth of the sun, as they seek to escape danger and, in this instance, finding a high perch to establish a territory as theirs.
Speaking of escaping danger, this lizard doesn’t usually look for a hole to hide in or cover to shelter it when it thinks it spots a predator. They do quite the opposite! Instead of running to a hole, they race to the nearest tree, or tree-like structure, climb several feet up and scamper to the opposite side. This escape method of quickly getting to the opposite side of a tree is not unique to Eastern Fence Lizards and can even be found in their distant relatives, the woodpeckers! (Woodpeckers will often land on a tree and immediately scurry 90o to 180o on the trunk of a tree to avoid being taken by a predator, such as a pursuing Accipiter hawk.)
As for the scientific name, the genus name of “Sceloporus” refers to pores found on the undersides of their hind legs that are used to excrete lipids for attracting mates and marking territory. The species name of “undulatus” is in reference to the wavy, dark bands that are often (but, not always) present on the backs of this lizard. You’ll notice that the lizards in these photos don’t exhibit clear markings, showing this isn’t always a diagnostic identification field marking.
In the early part of the spring at Harmony Hill, usually late March through early May, male Eastern Fence Lizards will find a stump, fallen log, fencepost, low branch or even the top of the root ball of an overturned tree and begin working to attract a potential mate. They also use this time to reinforce territorial boundaries for potential interloping males. Depending upon food resources, a territory could be as small as 50-75 m2. When food isn’t quite as abundant, that area could easily double.
As for their diet, it is varied and includes just about any invertebrate that they can fit into their mouths. Beetles, spiders, moths, butterflies, flies, cockroaches and even worms are on the menu. While they’re not particular about what they eat, they are fairly particular about how they catch their meals. Eastern Fence Lizards are incredibly dependent upon sight to hunt and choose to sit tight and let their camouflage work for them, waiting for possible food items to come to them. When an unsuspecting invertebrate gets near, the lizard will make a quick movement to catch it.
Sight isn’t only important for hunting; it is also critical to spotting a healthy and viable partner to mate with and pass along their genes. Male Eastern Fence Lizards develop large areas of bright blue markings on their undersides. On their throats and on the sides of their abdomens, an iridescent blue can be seen shining in the sun during breeding season. Females have some blue on their undersides, but nothing like what is found on the males.
Later in the early summer, females will usually lay between 4-14 eggs. At Harmony Hill, that tends to be very late May and into mid-June. Around the end of July, hatching begins, and miniature versions of the adults begin to roam the woodlands of the southern piedmont of South Carolina. Measuring about 1.5”-2”, the newly hatched lizards look very much like tiny versions of the females.
Adults can easily grow well above 6”, with females being larger than males. It isn’t out of the question to find females nearing 7.5”. This size difference between females and males, referred to as sexual dimorphism, finds females of this species being 10-15% larger than males. Fun fact… while females tend to be longer, overall, than males, they often have shorter tails than their male counterparts!
Life isn’t easy for our Eastern Fence Lizards, as they face a gauntlet of predators at just about every turn. Birds, such as American Crows, Blue Jays, American Kestrels and Loggerhead Shrikes are quite good at hunting them. And on the ground, a variety of snakes excel at capturing and consuming them. Now you see why they race to the nearest tree and quickly hide on the other side! Danger from above and below besets them all day!
The next time you find yourself wandering along the edge of an open forest, be sure to keep a keen eye out for these well-camouflaged reptiles and you just may witness pushups and head bobs. If you’re lucky, you’ll have the opportunity to watch one of the more common species of lizard in the southeast. And, if you take the time to soak up the gift of nature before you, you’ll learn that in no way does common mean ordinary or ugly! We, here at Harmony Hill, are not on the fence about the uncommon beauty of this common species.