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King cobra: a lover and a fighter
The king cobra is the world’s largest venomous snake – and a ruthless snake-hunter. But it is also a surprisingly devoted parent, as Romulus Whitaker found during 30 years of grappling with these enormous serpents in India.
The forests of Agumbe in Karnataka are the wettest and thickest in South India, and excellent snake habitat. I was walking along a forest path when I saw a black snake tail disappear into some bushes. “Rat snake!” I thought, and dived for it, bruising knees and elbows as my fingers wrapped around its smooth skin.
Just then, a deep growl emanated from the bushes. I looked up and towering above me was a king cobra, its golden hood afire in the evening light, its eyes pinned on me. I let go of its tail, but instead of attacking me, the cobra streaked off through the undergrowth.
I raced after the fleeing serpent, and grabbed its tail a second time. The cobra swung around and charged at me open-mouthed. Using a stick to keep the snake at bay, I managed to pull my sleeping bag out of my rucksack and prop it open. The cobra saw the dark hole as an escape route and slid inside. This was my very first encounter with a wild king cobra and I can still feel that adrenalin rush 30 years later.
What makes a king cobra scary is its size – males can reach over five metres long – and its venom. It has huge toxin glands in its ‘cheeks’ and can inject up to 7ml at a time (though, drop for drop, its venom is less toxic than that of a common cobra).
Despite its armoury, the king cobra’s instinctive response to humans is to flee. But they seem to find other animals less intimidating. One old report from Burma described a cobra biting a full-grown elephant on the trunk; the pachyderm died several hours later.
King cobras use their venom to subdue their prey – other snakes. Rising up over its intended victim, the king cobra clamps its jaws around the snake’s body and holds it in a suffocating grip until it stops struggling. The cobra’s venom attacks its victim’s nervous system, making its muscles limp. In about 10 minutes, the victim suffocates; swallowing takes another 10 or 15 minutes.
The snake is digested in a few days – bones, scales and all – and the king won’t have to eat again for weeks. Farmers near Mangalore witnessed a four-metre-long king cobra subdue and swallow a two-metre-long python, which it went on to digest in a ditch for the following week.
Make love, not war
Courtship is a tricky business for snake-eating snakes as the larger male king cobra could eat a female if he was hungry. As a precaution, male king cobras seem to lose their appetites during the breeding season. Meanwhile, the female lays a pheromone trail as she moves, announcing: “I'm a female king cobra.” With his tongue ‘tasting’ the way, a male can spend days trying to locate a female.
When the snakes finally meet, they follow a set ritual – if one gets the signals wrong, it could be fatal. As a male approaches, the female turns away and flashes her bright yellow hood chevron markings. Holding her head at an angle, she wraps her coils over her head; the series of bands flickering past his nose seem to confuse the male.
If the female doesn’t co-operate in the courtship, the male will cajole her by butting her with his head. Eventually, the female relents and the snakes mate, remaining in a coital embrace for an hour before going their separate ways.
Fighting not dancing
When two adult males meet, they may engage in strange, sinuous combat often mistaken for a mating dance. The cobras rise four feet off the ground, twine around each other and attempt to push each other down. The first snake to pin its opponent’s body to the ground is the winner – and they joust until one prevails.
It’s not clear why they do this: it may be over food, territory or females, or just excessive hormones in the breeding period. The struggle can last for hours and the snakes become oblivious to anything else – rain, shine or even human observers.
A unique feature of king cobra behaviour is the female’s habit of building a nest for her eggs. It is marvellous to watch how this limbless creature painstakingly scrapes together a huge pile of leaves, carrying plant material in a coil of her body numerous times until she has formed the base of her nest, then lays 20-30 eggs in the middle and piles more leaves on top to cover them.
The finished nest is about 40cm high and 1m in diameter, and the whole operation can take anything from 12 hours to four days.
Then the female stands guard over the nest for the two to three months it takes for her eggs to hatch. Her only sustenance is water when it rains. Her presence is enough to dissuade most animal intruders. But if that doesn’t work, she will put on a formidable display, hood spread, mouth open, growling like a dog.
The smell of the baby snakes bursting out of their eggs releases their hungry mother from her vigil and she leaves – probably just as well since she’s a snake-eater herself. Left to fend for themselves, most of the 30cm-long babies will be taken by predators, which include wild boar, mongooses, civets, birds, monitor lizards and other snakes. Only one or two hatchlings will survive to adulthood.
To see images of king cobras, click here.