Queensnake

The queen snake (Regina septemvittata) is a species of nonvenomous semiaquatic snake, a member of the subfamily Natricinae of the family Colubridae. The species is endemic to North America.

Common names

Regina septemvittata is known by many common names, including the following: banded water snake, brown queen snake, diamond-back water snake, leather snake, moon snake, North American seven-banded snake, olive water snake, pale snake, queen water snake, seven-striped water snake, striped water snake, three-striped water snake, willow snake, and yellow-bellied snake.

Geographic range

Regina septemvittata ranges through the temperate region of North America east of the Mississippi River from western New York state to Wisconsin and south to Alabama and northern Florida. There is also an isolated population in Arkansas that was discovered in 1894 and is thought to be an effect of climate change during the Pleiostene era. It is also found in the southwestern parts of Ontario.

Decreases in queen snake populations can be most attributed to a loss of food sources through stream channelization, bank erosion, and water pollution.

Appearance

The queen snake is similar in appearance to a garter snake, genus Thamnophis, so is often confused with that group. The queen snake is olive to gray or dark brown in overall coloration, with peach or yellow stripes that run down its length at the first scale row. There are also four prominent ventral stripes of a darker color, and as no other similar species has stripes running down the length of its belly, this is an important feature in identifying this snake. In the young and juvenile snakes there are three extra stripes: one stripe that runs along the vertebral dorsal scales, and two stripes (one on each side) that run down the length of the body at scale rows five and six. These extra stripes tend to fade as the snake matures, but when young the snake will have a total of seven stripes, three on the back and four on the belly, which gives cause for its taxonomical reference name, Regina (queen) septemvittata (seven-striped). The belly of the snake is a cream to yellow color.

The head of the queen snake is narrow and has nine large plate-like scales on the top, and the chin has several rows of thicker scales. This is a protective adaptation, for the snake's feeding habit of chasing its prey under rocks. The pupil of the eye is round, a feature shared with most other colubrids. There are 19 rows of keeled dorsal scales at midbody, and the anal plate is divided. The sexes are often difficult to distinguish based on external characteristics. Male queen snakes have relatively longer tails than females. Males have from 65 to 89 subcaudal scutes (average 76), with the tail from 23% to 34% of the snake's total length. Females have 54 to 87 subcaudals (average 69), with tails equal to 19% to 27% of total length.