By Doug Backlund

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Although it may come as a surprise to some, the status and distribution of many species of native plants and animals in South Dakota is poorly known. The conservation of our state’s wildlife is the responsibility of the state, and the primary agency responsible for wildlife conservation is the Department of Game, Fish and Parks. Just knowing where species occur and how they are doing is a big task. Many species are common and widespread but others are rare, limited in distribution or declining. These are the species that the South Dakota Natural Heritage Program, supported by the Department of Game, Fish and Parks, focuses on.

The lined snake is one of those species. It’s hard to believe, but in all of recorded history only three specimen records of the lined snake are known from South Dakota. The earliest report, from 1916, is very vague. A specimen was collected in July somewhere north of Sioux Falls and was deposited in the University of South Dakota herpetology collection. The second record is dated 1923 and is another USD specimen collected by W. H. Over on Brule Creek about 12 miles east of Vermillion. The most recent record is a specimen collected by Dr. Sven Froiland in 1964 in the Cactus Hills area northeast of Sioux Falls. A specimen is at Augustana College. Additional lined snake collections from South Dakota, if any exist, are unreported in the literature and there have been no reports from local naturalists and biologists since 1964.

The lined snake is distributed from southeast South Dakota and central Iowa south to central Texas. This is a prairie or woodland/prairie edge species and now occurs only where tracts of prairie remain relatively undisturbed. In Texas, Kansas and Oklahoma, where the species is more abundant, the lined snake also inhabits yards and other grassy habitats in towns and cities. Around the periphery of this region of higher abundance the distribution is broken into small, isolated populations. There are isolated populations in Illinois, Iowa, Missouri, Colorado, Minnesota and New Mexico. The only known population in Minnesota is found in Blue Mounds State Park, this population was discovered in 1972. Due to the rarity of this species in South Dakota, the evidence of declining populations in neighboring states, and the lack of recent reports of lined snakes, the lined snake was listed as state endangered in 1996, under the South Dakota Endangered Species Law.

Lined snakes are small, harmless snakes. They feed almost entirely on earthworms and are by nature secretive and retiring. Primarily nocturnal, lined snakes hide by day under rocks, logs, or other cover. Breeding occurs in the fall. Females become sexually mature by two years of age. The female retains sperm over the winter and fertilization occurs in the spring. In August the females give birth to 2-13 young snakes. The young are born live, in thin transparent membranes from which they quickly free themselves. Independent at birth, the young snakes must forage on their own to survive.

The lined snake is easily identified. No other snake in South Dakota has a combination of longitudinal stripes and two rows of half-moon shaped black spots on the belly scales. Juvenile lined snakes may have indistinct longitudinal stripes but the belly spots are very distinct. Lined snakes are usually less than 15 inches in length. The prairie ringneck snake also has black belly spots but the spots are not arranged in a double row. The prairie ringneck snake lacks longitudinal stripes and has a conspicuous yellow or orange ring around the neck.

Last July I took a trip to the Sioux Falls area specifically to search for lined snakes. In the back of my mind I wondered if these small snakes still survived in South Dakota. The first day of searching was hot, humid and discouraging. Many rocks and logs were rolled but all I found were northern prairie skinks and eastern garter snakes. My search was focused on native grasslands in the Cactus Hills, Palisades State Park, Dells of the Sioux near Dell Rapids, and other native grasslands protected from the plow by outcrops of Sioux quartzite. Since the only specimen with good locality data was from the Cactus Hills, I felt the efforts of the next and last field day should be used there.

Returning with a friend early the next morning, we began searching the prairie ridges of the Cactus Hills, rolling rocks, logs, and debris as we moved from ridge to ridge. Many regal fritillary butterflies, a prairie butterfly that has disappeared from most its range in the eastern United States, were seen on these ridges. A few wood thrush sang from the oak draws. We noted the housing development and sand/gravel mining that are encroaching on this unique natural area. Places like the Cactus Hills are becoming rarer with each passing year.

Two hours of searching finally paid off. I lifted an old piece of plywood and there was a flurry of activity. A northern prairie skink ran out one way, an eastern garter snake took off in another direction, and one snake remained motionless. That’s the one I grabbed and the grab proved to be a good one for I had a lined snake in hand, a record for the South Dakota Natural Heritage Program that proves the species still exists in the habitat where Sven Froiland collected one thirty-six years ago. After photographing the snake we released it where it was captured.

So what is the status of the lined snake in South Dakota? I hope that local naturalists and biologists will help us with that question. Anyone who is interested in searching for these snakes is encouraged to do so. Potential habitat is any native prairie in southeast South Dakota, especially near riparian areas or woodlands with deep, rich soils. Just remember that lined snakes are protected by state law and must be released. Anyone finding lined snakes is encouraged to contact the South Dakota Natural Heritage Program:

South Dakota Natural Heritage Program
South Dakota Department of Game, Fish and Parks
523 E. Capitol-Foss Bldg.
Pierre, SD 57501
(605) 773-4345