Michigan Society of Herpetologists
KIRTLAND'S SNAKE
Clonophis kirtlandii
Description: This small snake has four rows of alternating dark, rounded blotches running down the back and sides; these blotches are often faded and indistinct in very young and old adult individuals. The background color is reddish brown to grayish brown. A faint stripe is sometimes visible along the middle of the back. The small, narrow head (scarcely wider than the neck) is black or dark brown above, occasionally with some light mottling, while the labial scales and the chin and throat are a contrasting white, cream, or yellow. The belly is pink, red, or orange, with a row of black spots along each side, and there may be some irregular dark spotting between these lateral rows as well. There are 1 7 to 19 scale rows at midbody; the scales are keeled, and the anal plate is divided. Total adult length: 36 to 62.2 cm (14 to 24.5 in).
Adult males tend to be smaller (shorter and thinner-bodied) than females, and have proportionally longer tails (22 percent to 28 percent of total length, with 56 to 69 subcaudal scutes). The stouter females have tails 19 percent to 24 percent of total length and 44 to 61 subcaudals. Newborn Kirtland’s Snakes range in total length from 11 to 16.8 cm (4.3 to 6.6 in). They are darker above than the adults, with an indistinct (or sometimes nonexistent) blotch pattern, and have a deeper red color on the belly.
Back to TopConfusing Species: Garter snakes have lengthwise dorsal striping, pale unspotted bellies, and a single anal plate. The smaller Red-bellied Snake lacks both dorsal blotch ing and rows of spots on the belly. Copper-bellied Water Snakes grow larger and also lack the two rows of belly spots.
Distribution and Status: This species occurs in west and central Ohio, most of Indiana, southern Michigan, north-central Kentucky, and north-eastern and central Illinois; they have also been recorded in western Pennsylvania and extreme southeastern Wisconsin. Much of its known range is within the postglacial "prairie peninsula." Most recent Great Lakes area records for Kirtland’s Snake are clustered near the southern end of Lake Michigan (Cook County, Illinois, northwestern Indiana, and southwestern Michigan), and in Lucas County, Ohio (Toledo area).
This snake must be considered a rare and declining species throughout its range, despite its occasional occurrence in fairly dense local populations. It is presently recognized as "endangered" in Michigan and "threatened" in Indiana, and its future as part of the Great Lakes herpetofauna is precarious.
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Habitat and Ecology: Kirtland’s Snakes are usually found in damp habitats, often in the vicinity of streams, ditches, marshes, or ponds, but they are not truly aquatic. Open grassy habitats such as wet prairies, wet meadows, lens, swales, and pastures are preferred; they also occur in swampy woodlands, particularly in the unglaciated (southern edge) of its range. This species can be particularly abundant on undeveloped parcels of land in certain large metropolitan areas, but it is unclear whether these urban sites are preferred over more "natural" habitats, or whether the snakes are simply more accessible and easily found in these places (since they often hide under boards and other human-generated debris).
This is an extremely secretive species that spends much of its time below ground in burrows constructed by other animals, under leaf litter, or beneath logs, rocks, or other surface objects. Burrows of the chimney crayfish are a preferred retreat. Movement through subterranean habitats may be enhanced by this snake’s ability to flatten its body to almost ribbonlike proportions. Kirtland’s Snakes are active from late March or early April through late October or early November. The same burrows used as shelter during the active season undoubtedly serve as hibernation sites in winter. Most sightings of Kirtland’s Snakes are in early spring or fall; they appear to be largely nocturnal, particularly in summer.
Earthworms are the preferred food for this species, although slugs and perhaps terrestrial leeches are also eaten. Captives reportedly have consumed these food items as well as chopped fish but refused to eat small frogs, toads, and salamanders.
Natural predation on Kirtland’s Snake has not been reported in the Great Lakes region. Since they spend little time exposed on the surface, they are probably most vulnerable to burrowing predators such as Eastern Milk Snakes, shrews, and weasels. During their brief aboveground forays, they are vulnerable to hawks and owls, larger mammalian predators (foxes, raccoons, skunks, cats), and (inevitably) automobiles and unappreciative humans.
When threatened (especially when suddenly exposed), a Kirtland’s Snake can flatten its body to a remarkable degree and remain stiff and immobile. Upon further disturbance or if touched, it may violently writhe its body and attempt to hide its head, or suddenly dart into cover. Some individuals will strike and bite if cornered or grasped, but these little snakes are quite harmless to humans.
Back to TopReproduction and Growth: Mating has been observed in May under natural conditions. Females give birth to their young in late summer or early autumn (usually in August or September); litter size ranges from 4 to 15. At birth the young snakes are usually enclosed in a thin (chorionic) membrane from which they soon escape.
The little snakes grow rapidly, sometimes nearly doubling their lengths in the first full year. They probably reach sexual maturity within two years, with at least some females mating during their second spring after birth.
Back to TopConservation: Kirtland’s Snake certainly lost the vast majority of its original habitat as the wet grasslands of the "prairie peninsula" were converted to agricultural use, beginning early in the nineteenth century. This species is now largely restricted to isolated colonies, often surrounded by intensively farmed or developed lands that offer little or no opportunity for dispersal or genetic interchange.
As noted, this snake has been able to thrive in vacant grassy habitats in and near some large cities; however, these places are extremely vulnerable to development, and many urban sites for Clonophis have completely disappeared in recent years. An additional problem is that these attractive and harmless little snakes are coveted by some reptile hobbyists, and surviving urban populations are often discovered and heavily exploited by collectors. This practice is particularly tragic since Kirtland’s Snake is considered a "difficult" captive by most herpetologists and zoo professionals; few specimens survive more than a year in captivity.
Conserving this species will require identifying and protecting critical habitats, both in urban and rural areas. Legal protection by all states within its range would curtail pet trade exploitation, but a pulic-education campaign would be more effective in reducing incidental collecting and gratuitous killing.
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The above information has been reproduced or complied from the field guides with permission to use such material from the author, James Harding, for the sole use of educating the public on native Reptiles and Amphibians. The field guides used were: