Tuesday, July 24, 2012

Northern Fence Lizard

This prehistoric-looking little lizard is a Northern Fence Lizard (Sceloporus undulatus hyacinthinus) which is a subspecies of the Eastern Fence Lizard. They occur from New York, south to South Carolina, and west to Texas. In Missouri they are called Prairie Lizards (Sceloporus consobrinus),biologists have revised its taxonomy. Now, it's considered a distinct species. They are common and found in the Southern half of the state.

The ones in this article were photographed in Tennessee where they are still considered Northern Fence Lizards.

These lizards reach up to 7 inches in length with females being bigger than males. The males are dark gray or brown with very little or no pattern visible. They also possess bright blue belly patches and throat during mating season. Females have an obvious zig-zag or wavy pattern across their back and a white belly. There will be orange or red at the base of the tail. Some specimens may have some faint blue markings along their side.

Sometime between April and August males will seek females and mating will occur. Females will produce two separate clutches of up to 17 eggs. Males will bob their heads and do push-ups as a form of a mating dance. Mating will only occur if the female allows the male to approach her. Females may mate as early as one year of age but will only be able to produce one clutch of eggs. In the second year of life she will begin producing a second clutch.  Even though this species has been renamed and categorized in Missouri, the reproductive cycle is the same. The first clutch of eggs in Missouri are laid in May or June with the second clutch being laid in July. The female will dig a hole in loose dirt and lay her eggs in layers. A few eggs on the bottom layer, covered by dirt, then more eggs, covered with dirt, then more eggs and more dirt until all the eggs are laid. The total depth of the nest will be 4 inches or less. This species is even capable of retaining the eggs within their body and put off egg laying. This is beneficial during the second brood as it shortens the time needed for them to incubate and hatch. This allows the young lizards to grow some before the first frost sets in. These little lizards rarely live beyond three years in the wild as they fall victim to predators or harsh environments. They may live several more years in captivity.

These lizards are most active early in the day from about 8:00 AM to 1:00 PM, once the day becomes hot they go for cover  and will become active again towards dusk. They begin appearing in March and will remain active until October (weather permitting). Males are territorial and will often protect a small range that contains a few females. These are extremely fast lizards and difficult to catch or approach. As soon as they see a potential threat they run rapidly for cover or to opposite side of a tree or post.
Look for them along forest edges or within open woodlands. They are very common on rocky glades. They will hide out in fallen trees, old logs and stumps and in rock piles or brush piles. They will use "lizard highways" which will include fence rails, split rail fence, firewood piles, lumber piles, and railroad ties.
Fence lizards are beneficial to humans in the form of insect control, as they eat a wide variety of insects and spiders. They will also consume centipedes and snails.

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