THE SPOTTED NIGHT SNAKE

By Russell K. Grater,
Assistant Park Naturalist,
Zion National Park.

One of the least known of reptiles is the Spotted Night Snake, or Rock Snake, (Hypsiglena ochrorhynchus Cope). So infrequently is it encountered that the discovery of one is always news of more than momentary value. The snake is small, a 16-inch specimen being a rather large individual. The ground color is yellowish white, heavily peppered with light brown specks which give a general brownish appearance. There is a series of dark brown blotches along the back, generally arranged in two rows of alternating spots. Along the sides are similar but smaller spots in series of two, three, or four. Across the neck are dark blotches, or a dark collar. The pupils of the eyes are elliptical.

Comparativelly little is known about this snake, due to is secretive habits. It is nocturnal seldom being seen in the sunlight, and its discovery is usually accidental. It seems to prefer hiding under loose slabs of rock, and old boards. These hiding places are usually found on slops near streams, although other types of habitats are utilized. In captivity it is rather restless, and often does not take food readily. It will frequently climb when imprisoned, if given the opportunity, so it may be arboreal to some extent.

Insofar as is known, this reptile is non-venomous. While it possesses two large rear fangs that are faintly grooved, the poison apparatus Its lacking. These large fangs are apparently used to puncture the skin of the small lizards that are utilized as food. Practical tests have shown that that lizards whose skins are punctured by these teeth die quicker than those that were only badly bitten. It is believed that these punctures allow saliva from the snake's mouth to enter the blood streams of the victims. As saliva is a poisonous substance if introduced into the blood stream, death comes quicker than otherwise.

In 1933 the known range of the Spotted Night Snake was from Idaho, southward into northwestern Mexico, and from southern California eastward to southwestern Texas. More recently it has been collected in Washington, Colorado, Oklahoma, and Kansas, proving that its range is far from being definitely defined. Its habitats include areas from sea level to the tops of mountains and high plateaus. It seems to prefer the more arid habitats of the desert and near-desert life zones. Today, we call the Spotted Night Snake a rarity; tomorrow, it may be as of no unusual interest.