Why Do King Cobras Eat Other Snakes? A Snake-Eating Specialist

Which snakes do king cobras eat?

Studies of stomach contents, radio-tracked snakes and direct observations have recorded a long list of prey. Harmless colubrid snakes are the staple, especially large, common species such as the Oriental rat snake and other rat snakes, keelbacks, wolf snakes and whip snakes. These are long, fairly slender snakes that make a substantial meal.

King cobras also eat venomous snakes, including banded kraits, Indian cobras and pit vipers such as the Malabar pit viper and the hump-nosed pit viper. Young reticulated pythons are taken too. Older accounts describe king cobras eating pythons up to about 3 m (10 ft), but big adult pythons are far too strong to be prey.

Snakes are not the only food. Monitor lizards and other large lizards are eaten regularly, and in Singapore a king cobra was seen swallowing a clouded monitor. Birds and small mammals are occasional extras, mostly when snakes are scarce.

Why eat snakes at all?

For a long, slender predator, other snakes are an ideal shape of food. A snake can be swallowed whole without the jaws having to stretch around a wide body, so a king cobra can eat prey that is nearly as long as itself. A single meal provides a lot of energy relative to the effort of catching it.

Snakes are also plentiful in tropical Asia, and few other predators specialize in them, which means less competition. Specializing on snakes may also have driven the king cobra’s great size: being longer and larger than its prey gives it an advantage in the struggle that follows an attack.

The king cobra is not the only snake-eating snake. Kraits, coral snakes, the North American kingsnakes and the African file snakes eat other snakes too. What sets the king cobra apart is its size and its position as a top predator among snakes, dominant over all except the largest pythons.

How do king cobras hunt snakes?

King cobras are active by day and hunt by moving through the forest, often with the head raised slightly off the ground. They rely heavily on smell. The forked tongue collects scent particles and carries them to the Jacobson’s organ in the roof of the mouth, which lets the cobra follow another snake’s scent trail. Researchers in India have seen king cobras tracking pit vipers this way.

Once it finds its prey, the king cobra strikes and usually holds on. Its venom is mainly neurotoxic, so it paralyzes the prey and stops it from fighting back or escaping. This is especially important with venomous prey, because a bite from a krait or cobra could harm the hunter. In some cases the king cobra also wraps its body around struggling prey, although true constriction is unusual. Our article how venomous is a king cobra? explains the venom in detail.

How does a king cobra swallow another snake?

Like all snakes, the king cobra swallows its food whole. It normally starts at the head, so the prey’s scales lie flat and it slides down smoothly. The lower jaw has two halves joined by a stretchy ligament, and the jaw bones are loosely hinged to the skull, so the cobra can “walk” its jaws forward over the prey one side at a time.

A long snake folds up inside the stomach as it goes down. Swallowing can take some time, and the king cobra is vulnerable while it eats, so it often feeds in cover. Read more in how do snakes swallow large prey?

How long can king cobras go without eating?

After a large meal, a king cobra may not eat again for weeks or even months. Like other snakes, it is ectothermic, meaning it relies on outside heat rather than burning food to stay warm, and it has a slow metabolism. A meal of another snake, often a large share of its own body weight, provides enough energy for a long time.

Females may also eat little or nothing while they build and guard their nests. Our guide how long can snakes go without eating? compares fasting across snake species.

Do king cobras eat each other?

Yes. Cannibalism has been recorded in king cobras, with larger snakes eating smaller ones, including juveniles. For a snake-eater, a smaller king cobra is simply another snake. This may be one reason young king cobras are nervous and quick to flee, and why hatchlings disperse quickly from the nest.

Why this matters for people

Because king cobras eat snakes, they help regulate populations of other snakes, including venomous kraits and cobras that cause many bites in South Asia. Rat snakes, a common prey, are themselves important rodent hunters, so the king cobra sits near the top of a food web in which snakes and rodents interact. Losing king cobras through forest clearance and killing may therefore change the balance of snake communities in ways that are not yet well understood.