Milk Snakes have a large number of subspecies throughout the roughly eastern and southern two thirds of the country. The subspecies we have is the Pale Milk Snake (Lampropeltis triangulum) multistrata.
In general, Milk Snakes look like they are banded with three colors: orange or reddish orange, pale yellow to grey to white and with intervening and narrower black. Milk Snakes can be distinguished from the venomous coral snakes which have red next to yellow and live far, far to the south of Bighorn Canyon.
Upon closer inspection of the Pale Milk Snakes it is realized that they are not banded, but have wide orange blotches with narrow black borders that reach well down the sides. The narrow pale yellow to cream between the blotches and on the belly is much closer in width to the black borders, than it is to the much wider orange blotches.
The widths and shades vary from individual to individual. They are very colorful snakes and are the most brightly colored when young. Adults are between 16 and 32 inches long and the hatchlings are just 5 to 8 inches long. The head and neck width just continue undistinguished into the body.
The carnivorous milk snakes eat mostly small vertebrates including snakes, lizards such as sagebrush lizards, prairie lizards, and six-lined racerunners, reptile eggs, birds and bird eggs, small mammals, especially mice and voles, and even insects and worms.
The Pale Milk Snake is found on the northern plains of Nebraska and South Dakota and into Montana and down into the Bighorn Basin. All the other subspecies are either to the east or south of us. They are found in the open prairie, open sagebrush and also into the Ponderosa pines, as well as rocky outcrops, hillsides and badland scarps.
A winter hibernation of three months or more seems to be necessary to stimulate breeding. They are tolerant of colder temperatures and this could just be that they have adapted to the conditions in their home range. Breeding takes place after they have warmed up generally in May.
The male will usually bite the female behind the head while copulating and copulation can extend for several hours. A clutch of 2 to 9 eggs will be laid 30 to 40 days after fertilization, usually between mid-June to mid-July. Incubation takes about 60 days depending upon temperatures but usually beginning in late August and through September. The young must then fend for themselves. The females reach sexual maturity in their third or fourth year.
A Wild Life
The longevity of these uncommon snakes in the wild is unknown, but some in captivity have reached over 20 years. They are among those species that are not well studied or known.
Thus, the most prudent steps to protect them should at least include protecting their dens and regulating commercial harvest for the pet trade. Most wild animals do not make good pets, and if released back into the wild where they are not native, they can cause significant environmental problems.