DESERT SUN (Palm Springs, California) 31 August 08 Beware of venomous night snake (Jim Cornett)
The night snake is second only to the gopher snake in having the most extensive distribution in the western United States. It is found throughout the Coachella Valley as well as the entire North American desert, wherever stabilized soils and scattered rocks and boulders characterize the landscape.
The range of the night snake is closely aligned with that of the abundant side-blotched lizard. This should not be surprising since the lizard is important food for the night snake. The size match is perfect. A full-grown night snake can be expected to reach 16 inches long, and the lizard, not counting the tail, typically reaches just over 2 inches long. That is a large enough meal to sustain a night snake for several weeks.
The distributional success of the night snake can by explained by its utilization of the side-blotched lizard as food. The side-blotched lizard relies on ants as a staple food.
Ants, particularly harvester ants, withstand seasonal and long-term drought cycles quite well. The ants consume the abundant seeds dropped on desert soils. Even through long periods of drought, many ant colonies survive, thus sustaining the side-blotched lizard, which in turn sustains the night snake. The importance of these kinds of food chains, which sustain a series of animal species during prolonged droughts, cannot be overstated.
Though the side-blotched lizard is the most important prey for the night snake, almost any small or recently hatched lizard species will do. Hatchling night snakes do not appear until late summer, at a time when all species of lizard eggs have hatched, including, of course, the side-blotched lizard. This insures that a young night snake has plenty of hatchling lizards on which to feed.
Small snakes, including blind snakes; frogs; and salamanders, are also taken when available.
The night snake has enlarged rear teeth in the back of its upper jaw. These fangs facilitate the entry of a mild venom that can be sufficient to kill lizards. In order to envenomate prey, however, the night snake must work the victim far enough into its jaws so that the rear-mounted fangs can penetrate the skin. Rear-mounted fangs are not nearly as effective as the hollow, front-mounted fangs of coral snakes and rattlesnakes.
As its name indicates, the night snake is strictly nocturnal and possesses vertical pupils that open wide in the dark. It is relatively common, but its small size and spotted, brownish color make it easy to miss even on paved roads.
Breeding occurs in spring, with females laying up to nine eggs in late spring or early summer.
Jim Cornett is a desert biologist living in Palm Springs.
Beware of venomous night snake