Lined Snake (Tropidoclonion lineatum)

Lined SnakeĀ  (Tropidoclonion lineatum)

by Jeff LeClere

A lined snake, Tropidoclonion lineatum, from Adair County, Iowa.


PROTECTED and Species of Greatest Conservation Need. It is illegal to kill or collect this species by law in Iowa. Lined snakes are secretive and not commonly seen. We would welcome any reports of lined snakes to help us fill in the gaps of its presently spotty distribution.


Harmless to humans. This snake resembles a small, colorless garter snake. The lined snake is 8 – 10 inches long. There is little variation in this species so identification is easy. There is a light (almost always white; rarely yellow) mid dorsal stripe. There is also a light lateral stripe on each side of the snake. Ground color is gray or brown and there are some dark dots between the dorsal and lateral stripes. The belly is plain white with two rows of bold, black half-moons down the center. Sometimes there is a yellowish stripe over the moons, but they still retain their boldness. This characteristic is enough to distinguish it from all our other snakes. The scales are keeled and the anal plate is single. No other Iowa snake has a double row of black half-moons down the belly.


No subspecies of the lined snake, Tropidoclonion lineatum, are recognized any longer.


Range map for the lined snake in Iowa

The lined snake is found in scattered populations in northwestern and throughout southern Iowa. We would like to hear of reports of this snake.


Lined snakes are found in prairies, grasslands, pastures, woodland edges, and even city parks, city lots, cemeteries, and backyards.


Lined snakes are secretive snakes hiding beneath debris during the day. They often hunt at night above ground when earthworms are present and easily captured. This snake is inoffensive and if it were to bite, it could do no damage at all. It breeds in the fall; this is why most specimens are found during this time in Minnesota and Iowa. I have seen many road-killed specimens in Cherokee County in October moving to their hibernacula. In other states, they may also be quite common in the spring, however. The female gives birth to 5 – 10 young in autumn. They are three inches long at birth. Lined snakes overwinter deep in rocky outcroppings or burrows.


Lined snakes’ favorite food is earthworms, but slugs, snails, soft-bodied insects are also consumed.