Species Profile: Sceloporus undulatus – Eastern Fence Lizard
Scientific Name: Sceloporus undulatus
Common Name(s): Eastern Fence Lizard, Prairie Lizard, Fence Swift, Gray Lizard, Northern Fence Lizard, Pine Lizard, Horn-billed Lizard
The eastern fence lizard is a member of the spiny lizard family. The lizards can range from 4 to 7.25 inches in length, including the tail. The scales on the lizard are rough and pointed. Its coloring is usually grayish but can range from nearly black to brown. During the summer season, male fence lizards can have bright blue patches on their throat and belly, while female lizards often have a black horizontal pattern on their back throughout the entire year. One could mistake a western fence lizard as an eastern fence lizard, but they have a slightly different pattern, number of scales, and range of distribution. The western and eastern fence lizards are separated by the Rocky Mountains.
The eastern fence lizard is found as far north as New York and as far south as northern Florida. They are found as far west as Arizona and Utah, and they are separated from the western fence snake by the Rocky Mountains.
The eastern fence lizard eats a wide variety of insects, spiders, and other invertebrates. Most of the time fence lizards are arboreal, meaning tree-dwelling, and move between trees when approached. They prefer dry, open forests or glades with stumps and logs to escape predators, such as the ratsnakes. Being relatively small, the fence lizard itself is often prey for birds, larger lizard species, snakes, and domestic cats and dogs.
To attract female lizards, the male lizard will perform “push-ups” to attract mates and to keep other males from invading their territory. Fence lizards’ mate in the spring and lay 3-16 eggs in late spring or early summer.; eggs hatch after 10 weeks. Young are left to their own defenses after they hatch, so there is a high mortality rate.
In the past century, some eastern fence lizards have adapted to have longer legs and new behaviors to escape the non-native fire ant, which can kill the lizard in under a minute. Fire ants also occupy nesting habitats used by eastern fence lizards. Studies have found that fence lizard nests are vulnerable to fire ant predation. In geographic areas where the fire ant has not invaded, morphological and behavioral changes in fence lizards have not occurred.
Here in Bella Vista, fence lizards can be found in most of our forested areas, but they are well camouflaged. They are also often seen along fences, as their name implies, as well as wood piles and the sides of houses.