King Cobra: The World’s Longest Venomous Snake

Species Published : Aug 09, 2019 Updated : Sep 24, 2023
How does the cannibalistic, snake-eating king cobra manage to multiply and survive?
King Cobra: The World’s Longest Venomous Snake
How does the cannibalistic, snake-eating king cobra manage to multiply and survive?

King cobras incite awe, fear, intrigue and a lot of respect. But king cobras (Ophiophagus hannah) are actually not really cobras! They belong to a separate genus called Ophiophagus, where Ophio refers to snake and phagus means eater, i.e. king cobras are primarily snake eaters and occasionally feed on monitor lizards.

King cobras are found across Southeast Asia. In India they inhabit a range of different habitats: wet forests of the Western Ghats and Northeast, dry areas along the Eastern Ghats, cold climes of the lower Himalayan regions, and even in hot humid areas of the Andaman Islands.

King cobras are top predators among snakes, and true to their name, conduct themselves with poise seldom seen in any other species. They are excellent climbers, great swimmers, adept at cruising the forest floor or the upper canopy. They rarely attempt to hide or move undercover. They are out there chasing their prey, or defending or wooing a mate irrespective of the location, be it a forest floor, canopy, in water, or even amidst people’s homes, farms, or backyards.

Known to reach lengths of over five metres, the king cobra is the longest venomous snake in the world. When they feel threatened they assume an aggressive posture where they expand the sides of their neck to create a menacing hood. Photos: Pradeep Hegde
Known to reach lengths of over five metres, the king cobra is the longest venomous snake in the world. When they feel threatened they assume an aggressive posture where they expand the sides of their neck to create a menacing hood. Photos: Pradeep Hegde

King cobras are a diurnal species, most active from the early morning, and settling down by evening or night. If confronted, they stand their ground, hooding up to 1/3rd of their body length, which means, a 15-foot-long adult can hood up to 5-feet, and look straight into the eyes of an average adult Indian. At 18 feet these snakes are the longest venomous snakes in the world.

The king cobra is found across a wide variety of habitats ranging from forests, mangrove swamps, agricultural areas to tea estates. Photo Courtesy:  Pradeep Hegde
The king cobra is found across a wide variety of habitats ranging from forests, mangrove swamps, agricultural areas to tea estates. Photo Courtesy: Pradeep Hegde

However intimidating they may appear, they rarely strike in haste. They give enough time for the contender or intruder to leave them alone. If the warning is ignored, king cobras can bite and pump in neurotoxic venom, a full 7 cc, among the largest quantity for any snake. These digestive enzymes kill their prey in no time. Though this venom is not as toxic as a common cobra’s (Naja naja), the quantity than can be delivered in a single bite is potent enough to kill a man in less than thirty minutes. With no anti-venom available in India for king cobra bites, there is no way a bite victim has any chance of survival. However, we need to remember that humans are of no interest or consequence to king cobras, they are more a hassle and unnecessary trouble. King cobras are only concerned with snakes which they can dine on, and other king cobras that they can eat (they are cannibalistic) or a female to mate with.

When male king cobras combat for rights to mate with a female, they often turn blind to their environment. Photo: Gowri Shankar
When male king cobras combat for rights to mate with a female, they often turn blind to their environment. Photo: Gowri Shankar

Female king cobras are much smaller in size, but queens nonetheless. These snakes are the only ones in the world that build a nest and care for their eggs. During mating season, which is typically between February to March in the Western Ghats, female king cobras release pheromones to attract males. These pheromones act as an invitation for males to recognise that they are potential mates and not meals. Captivated by these invitations, males cover great distances, crossing territorial boundaries, and human landscapes only to find several males vying for the attention of a single female.

Female king cobras are very cautious and shelter in a safe place, usually a burrow. The contending males rise up for duel in which each male entwines around the other trying to subdue it by pushing the head to the ground. This is called male combat which may last for minutes or hours. Totally engrossed, these males become oblivious to their surroundings. Such fights have been witnessed by people on main roads and in backyards. After many combat sessions take place, finally after several days the mating ritual ensues between the female and the ‘winner’ male. Mating is a sober graceful display where the male entices the female by butting his head on her body, and the female king cobra spreads out her hood in submission and acceptance. He gently slides over her body and with their tails entangled, deposits his sperms to ensure their progeny. Mating happens several times over the next couple of days. After close to a month, during which neither male nor female eat, the male leaves his queen and moves away, lest he makes her his meal.

The responsibility of ensuring the success of their progeny now rests solely with the queen. The female remains close to the burrow where she undergoes ecdysis, a process where a snake sheds its skin. This process occurs once every 2-3 months in both male and female king cobras. It is nature’s way of ensuring they are clean and free of ticks and other parasites.

King cobras generally do take shelter in burrows, but the king cobra female is the only snake known to builds a nest in which she lays and protects her eggs. Photo: Gowri Shankar
King cobras generally do take shelter in burrows, but the king cobra female is the only snake known to builds a nest in which she lays and protects her eggs. Photo: Gowri Shankar

The pregnant queen with 30-40 eggs (varies depending on her age and size) scouts for the best spot to build her nest. She selects a sloping patch to ensure the runoff of rainwater, usually under the right mix of shade and sunlight, and uses dried fallen leaves, looping it in swirls to build her nest. After over 15 days of hard work, she rests on top of her three-foot-tall and five-foot-wide nest, and guards it against predators and intruders, which usually include mongoose, humans, and sometimes stray dogs.

Seasons change, from sweltering humid days to the monsoon with four months of incessant rain. After 70-90 days baby king cobras hatch out from their leathery egg cases. Just before the hatchlings emerge, the queen leaves the nest to ensure she doesn’t feed on her own offspring. They survive on the remnants of their yolk for a week, and although only 25 cm long and 50 gm in weight, they are born with venom to kill and the ability to fend for themselves. However, they are still at a vulnerable stage where they can be eaten by birds of prey, mongoose, other snakes, and sometimes other king cobras. Of the 30-40 hatchlings hardly two or three will survive to adulthood.

More vibrantly coloured than the adult, the king cobra hatchling is highly vulnerable to predation. Photo: Gowri Shankar
More vibrantly coloured than the adult, the king cobra hatchling is highly vulnerable to predation. Photo: Gowri Shankar

Of all the places that king cobras are found in India, there is no other place other than Agumbe, Karnataka where these snakes are revered, protected, and tolerated by the local population. The presence of environmental NGOs and snake rescuers in the area adds to their confidence. It is only as recently as a decade or more ago that serious research has been carried out on this species in the Western Ghats. These have revealed interesting insights, and wildlife documentaries too have done well to showcase their secretive lives.

In the Western Ghats king cobras live in various habitats, from rainforests to plantations and agricultural fields. Photo Courtesy:  Kalinga Centre for Rainforest Ecology
In the Western Ghats king cobras live in various habitats, from rainforests to plantations and agricultural fields. Photo Courtesy: Kalinga Centre for Rainforest Ecology

King cobras deserve their kingdoms and the freedom to thrive. It is up to us to ensure their habitats are protected and their lives are not endangered and that we take pride in sharing a home with a majestic and unique species of snake.

The future of king cobras is challenged by numerous threats. Habitat destruction tops the list followed by hunting for skin, meat, and the pet trade. They are listed as ‘Vulnerable’ under the IUCN Red List, but given the current scenario, a reassessment is most essential.

As part of creating awareness about these snakes, Kalinga Foundation conducts workshops on the ecology, rescue, and relocation of king cobras across India. Kalinga Centre for Rainforest Ecology conducts the annual king cobra bionomics and conservation workshop for people who are keen to learn more about these magnificent snakes. To participate, those interested can contact them at kalinga@kalingacre.com or +91 9480877670.

Belonging to the genus Ophiophagus (a Greek-derived word meaning snake-eater), the king cobra will not hesitate to climb trees in pursuit of its primary prey, other snakes. Photo:  Shreeram MV
Belonging to the genus Ophiophagus (a Greek-derived word meaning snake-eater), the king cobra will not hesitate to climb trees in pursuit of its primary prey, other snakes. Photo: Shreeram MV


About the authors

Gowri Shankar

Gowri Shankar

is co-founder and director of Kalinga Foundation and Kalinga Centre for Rainforest Ecology (KCRE).
Sharmila Shankar

Sharmila Shankar

is assistant director of KCRE.

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