Reptiles
Eastern Kingsnake
Lampropeltis getula · also called common kingsnake, chain kingsnake
The eastern kingsnake earns its name the same way the king cobra does: it eats other snakes. It hunts down copperheads and rattlesnakes, wraps them in coils, and swallows them, and it can take a defensive bite from one of them and barely notice.
Overview
Lampropeltis getula is a glossy blue-black snake with a chain-like pattern of thin cream bands, found across the southeastern United States in pine and hardwood forest, swamp edges, and farmland. It is a powerful constrictor whose diet is heavy on other snakes, along with lizards, rodents, birds, and eggs.
The snake-eater
It regularly kills and eats copperheads, cottonmouths, coral snakes, and rattlesnakes, seizing them by the head and constricting before the fangs can be brought to bear. Its blood also contains proteins that neutralise pit viper venom, so a bite from its venomous prey does little harm.
Harmless, and helpful
It has no venom, rarely bites, and keeps local copperhead and rodent numbers down, so landowners who know it protect it.
Status
Least Concern overall, but the eastern chain kingsnake has declined sharply and mysteriously across much of the Southeast since the 1970s, with fire ants, habitat change, disease, and pollutants all suspected.
Eastern Kingsnake: common questions
Why is it called a kingsnake?
Because it eats other snakes, in the same sense that a king cobra is a king. The kingsnakes and milk snakes of the genus Lampropeltis are strong constrictors whose diet is heavy on other snakes, and the eastern kingsnake is a specialist at it, routinely killing and eating species that would be dangerous to almost any other predator. The name reflects that it sits above other snakes in the local food web. It is not related to the king cobra, which arrived at the same lifestyle and the same regal nickname independently on another continent.
How can a kingsnake eat a rattlesnake without being poisoned?
Two things protect it. First, its hunting technique minimises the risk, since it grabs the venomous snake by the head or neck and immediately wraps it in constricting coils, so the prey often cannot bring its fangs to bear before it is overpowered. Second, and more remarkably, the kingsnake is physiologically resistant to pit viper venom. Its blood serum contains proteins that bind to and inactivate key venom toxins, so even when a copperhead or rattlesnake does land a defensive bite, the venom does far less damage to a kingsnake than it would to a mammal or another snake. This resistance is specific to the venoms of snakes in its own range and does not extend to, say, cobra venom.
Is the eastern kingsnake dangerous to people or pets?
Not at all. It has no venom, its teeth are small, and it is generally a calm snake that would rather flee, curl into a ball, or release musk than bite; a large one that is grabbed may nip, which is harmless. It poses no threat to a dog or cat. In fact it is one of the best snakes to have on a property, because it preys on copperheads, rats, and other snakes, and long-time rural residents in the Southeast have traditionally protected kingsnakes for exactly that reason.
Why is the eastern kingsnake disappearing in the Southeast?
This is one of the odder puzzles in North American herpetology. In parts of Florida, Georgia, and the Carolinas, the eastern kingsnake went from being one of the most commonly encountered snakes in the 1970s to being rare or absent, often in habitat that still looks suitable and still holds plenty of other snakes. Suspected causes include invasive fire ants killing hatchlings and raiding nests, subtle habitat degradation, an unidentified disease, heavy road mortality, and bioaccumulation of mercury and other contaminants in a snake that sits high in the food chain, but no single explanation has been confirmed, and the declines continue to be studied.