Eastern milksnake

Identification

The eastern milksnake is a slender snake with smooth scales and a narrow head only slightly wider than its neck¹. Adults are grey to tan with three to five rows of black-edged brown or reddish-brown blotches, and there is usually a light V- or Y-shaped mark on the back of the head^1,2. The belly has a black-and-white checkerboard pattern¹. Young milksnakes have bright red blotches, and their colours dull with age¹.

Most adults are 61–90 cm long, and the record length is 132.1 cm². Hatchlings are about 20–25 cm long³.

Distribution

The eastern milksnake lives in south-eastern Canada, in southern Ontario and south-western Quebec, and across much of the eastern and central United States^5,7. The Reptile Database lists it from southern Maine west to Minnesota, Iowa and parts of the Great Plains, and south to the northern parts of Alabama, Georgia and Louisiana⁵.

In 2014 a genetic study split the wide-ranging milksnake of the Americas into several species, and the name Lampropeltis triangulum now applies only to the eastern milksnake^5,6,7. It is the most northerly of these species and the only one found in Canada⁷. Whether the Central Plains milksnake (L. gentilis) should be kept separate from it is still debated⁵.

Habitat

The eastern milksnake uses a wide range of habitats, including farmland, meadows, old fields, river bottoms, bogs, rocky hillsides, and both coniferous and deciduous forest^1,3. These places need plenty of cover and a healthy population of rodents¹. It is often found around houses, barns and other buildings^1,4. In winter it shelters underground, in places such as old wells, stone walls, rock crevices and sometimes the basements of homes^1,4.

Behaviour

The eastern milksnake is secretive and spends most of its time hidden under logs, boards, rocks and other debris, seldom basking in the open¹. It is mainly active at night¹. When disturbed it usually stays still or crawls away, but if harassed it may vibrate the tip of its tail and strike repeatedly¹. Because of this tail-vibrating, it is often mistaken for a rattlesnake⁴. It is eaten by birds of prey and mammals, and many are killed on roads³.

Diet

It is a constrictor that feeds mainly on mice and other small mammals, such as voles and shrews^1,4. It also eats other snakes, birds and their eggs, reptile eggs, frogs and even slugs^1,3. Its habit of hunting rodents in barns led to the old, false belief that it sucks milk from cows by night, which is how it got its name^1,4.

Reproduction

The eastern milksnake lays eggs⁵. Adults mate in spring or early summer, and females lay 6–24 eggs, 13 on average, in loose soil or rotting logs from mid-June to July^1,3. Eggs have also been found in sawdust, manure and sand⁴. They hatch after about 42–56 days, between late August and October¹.

Venom and medical significance

The eastern milksnake is non-venomous and harmless to people^1,2. If it is startled or cornered it may strike in self-defence, but its teeth can barely puncture the skin¹. Its main importance is that people often mistake it for the venomous copperhead and kill it¹.

Conservation

The eastern milksnake is listed as Least Concern on the IUCN Red List, in an assessment published in 2019⁸. In Canada, COSEWIC lists it as Special Concern, a status first given in 2002 and confirmed in 2014⁷. The main threats there are the loss of habitat to towns and farmland, road deaths, deliberate killing and collection for the pet trade⁷.

Similar species

The eastern milksnake is most often confused with the venomous copperhead (Agkistrodon contortrix), and many reported “copperheads” in basements turn out to be milksnakes¹. A copperhead has a plain copper-coloured head, a broad triangular head on a narrow neck, a single row of crossbands and keeled scales, while the milksnake has a narrow head with a light V or Y mark, three to five rows of blotches and smooth scales¹. Red-marked milksnakes are also confused with coral snakes, but in milksnakes the red markings touch black, while in the eastern coral snake the red rings touch yellow and the snout is black^9,10.

The rhyme “red touches yellow, kills a fellow; red touches black, venom lack” only works for coral snakes in the United States; some coral snakes in Mexico, Central America and South America have red rings touching white or even black, so the rhyme must not be relied on there⁹. These differences are not a safe basis for handling any snake. Keep your distance from every snake you cannot identify.

In captivity

Milksnakes are kept as pets, and wild eastern milksnakes are collected for the pet trade in some places^3,7. Milksnakes recorded as Lampropeltis triangulum have lived for up to 22.6 years in captivity¹¹. The RSPCA advises keeping Lampropeltis snakes singly, because they eat other snakes and may attack or even eat each other¹². Wild snakes should never be collected as pets¹.