Rough Greensnake

Opheodrys aestivus, commonly known as the rough green snake, is a species of nonvenomous North American snake in the subfamily Colubrinae of the family Colubridae. The species is sometimes called grass snake or green grass snake, but these names are more commonly applied to the smooth green snake (Opheodrys vernalis). The European colubrid called grass snake (Natrix natrix) is not closely related. The rough green snake is docile, often allowing close approach by humans, and rarely bites. Even when bites occur, they have no venom and are harmless.

Description

The rough green snake (Opheodrys aestivus) is bright green above and has a yellowish belly, affording it excellent camouflage in green vegetation and making it difficult to see in the wild even though it is relatively common in its habitat. It has keeled dorsal scales, which are arranged in 17 rows at mid-body. It grows up to 116 cm (45+3⁄4 in) in total length (tail included) and is very thin.

Etymology

The specific name, aestivus, is Latin for "summer" in reference to the species' green dorsal color. The generic name, Opheodrys, is derived from Greek ophios, meaning "serpent", and drys, "tree".

Geographic range

The rough green snake ranges throughout the Southeastern United States, from Florida, north to Southern New Jersey, Indiana, and west to Central Texas. At the edge of the species' population, in states such as New Jersey, Indiana, and Kansas, it is often isolated and dependent on locally humid microclimates. The snake is commonly found in the Piedmont and Atlantic coastal plain, but is not found in the higher elevations of the Appalachian Mountains. It is also found in northeastern Mexico, including the state of Tamaulipas and eastern Nuevo León.

Habitat and behavior

The preferred natural habitat of Opheodrys aestivus is moist meadows and woodlands, typically near water. It is highly arboreal, and prefers a narrow arboreal microhabitat of dense brush in edge situations. This microhabitat is found in a variety of habitats, such as lakeshores, streambanks, and upland ravines. The rough green snake also commonly uses disturbed edge habitats alongside roads for thermoregulation and refuge. If kept in captivity it is recommended that it be in a taller enclosure with plenty of cover and climbing opportunities. It is frequently found climbing in low vegetation, and is also a good swimmer. However, it is often found on the ground as well. Unlike many snakes, it is largely diurnal. At night it is found coiled in the branches of trees. Preference is given to perches based upon distance from the shoreline, height of branches, and thickness of the individual branch.

Diet

Opheodrys aestivus is a dietary specialist, preying on insects and other arthropods. The diet of O. aestivus consists mostly of insects and other terrestrial arthropods, but some snails and tree frogs are also eaten. This snake is not a constrictor; most prey are grabbed and overpowered by its jaws which are unusually strong for a snake. O. aestivus has been shown to rely heavily on visual cues for prey detection and to prefer living prey items. As foraging activity increases, the tongue evolves greater elongation and deeper forking, and the abundance of chemoreceptors rises in the vomeronasal organs, the chemosensory responsiveness is adjusted to match diet. Orthopterans constitute 16.9% and all arthropods about 98% of dietary volume of the rough green snake. The rough green snake exhibits greater chemosensory investigation of chemical cues from its insect prey than from representatives of other taxa because of the linked importance of insects to its diet. It is able to live away from standing water by sucking droplets of dew from leaves.

As prey