Species within this class are cold-blooded, such as snakes, lizards, and turtles. Reptiles have an external covering of scales or horny plates and breathe by means of lungs. Reptiles do not form a distinct evolutionary group as birds and mammals do. Instead, the Class Reptilia consists of four orders which are very different from each other. As an example, lizards are more closely related to birds than to turtles. Reptiles differ from amphibians in that they have dry, waterproof skin and they lay eggs with shell coverings. In addition they have more advanced circulatory, respiratory, excretory, and nervous systems.
There are twenty-six species of reptiles found at Shenandoah including eighteen snakes, five turtles, and lizards.
Man's fear of snakes likely results in large numbers of them killed each year. Others (including turtles) perish from motor vehicle activity along Skyline Drive. Additionally, illegal collecting (poaching) of certain species such as timber rattlesnakes or box turtles, accounts for additional losses. These animals are usually sought for their value in the illegal pet trade and black market arenas. Currently, the park has little information as to how these illegal activities may be affecting reptile populations.