King Cobra

About the king cobra

The king cobra is a species complex of snakes endemic to Asia, and it is the world's longest venomous snake, with an average length of 3.18 to 4 m (10.4 to 13.1 ft) and a record length of 5.85 m (19.2 ft). Despite its common name, it is not a true cobra in the genus Naja; it belongs to its own genus, Ophiophagus, a name derived from its habit of eating other snakes. Genetic analysis suggests the king cobra is actually an early offshoot of the lineage that gave rise to the mambas, rather than a close relative of the true cobras. It is widely distributed across tropical Asia, spanning the Indian subcontinent through Southeast Asia to southern China, though it is not commonly seen. Recent taxonomic work suggests the species may in fact be a complex of at least four distinct species, spread across its large range and separated by differences in color pattern and other traits.

Coloration varies across the king cobra's range, from black with white stripes to unbroken brownish gray. The skin is typically olive green with black and white bands on the trunk that converge toward the head, and the head itself is covered by 15 drab-colored, black-edged shields. The muzzle is rounded, the tongue black, and the large eyes have a golden iris with round pupils. The hood is oval-shaped, covered in smooth olive-green scales with two black spots near its base, and the cylindrical tail is yellowish green above, marked with black. Juveniles look markedly different from adults: they are black with chevron-shaped white, yellow, or buff bars pointing toward the head, and their bright juvenile colors fade as they mature. The species is sexually dimorphic, with males larger and paler than females, especially during the breeding season; males captured in Kerala, India, measured up to 3.75 m (12.3 ft) and weighed up to 10 kg (22 lb), while females reached a maximum of 2.75 m (9 ft) and 5 kg (11 lb).

Behavior and diet

The king cobra hunts chiefly other snakes, including members of its own species, making it an apex predator that is dominant over all other snakes except large pythons. Recorded prey includes monitor lizards, the Indian cobra, banded krait, Oriental rat snake, reticulated python, green whip snake, Himalayan keelback, banded wolf snake, and Blyth's reticulated snake; it also tracks the Malabar pit viper and hump-nosed pit viper by following their scent trails, and in Singapore one individual was observed swallowing a clouded monitor. When food is scarce, it turns to other small vertebrates such as birds and lizards. After a large meal, its slow metabolic rate lets it go many months before eating again. It is generally considered diurnal, hunting during the day, though it has occasionally been seen active at night.

Despite its fearsome reputation, the king cobra is not considered aggressive and typically avoids humans, slinking away when disturbed. It is, however, known to defend incubating eggs aggressively and to attack intruders rapidly in that context. When alarmed, it raises the front of its body, spreads its hood, bares its fangs, and hisses, a sound low enough in pitch that it is often described as a "growl" rather than a hiss, closer in frequency to a human voice than the hiss of most other snakes. It can strike at considerable range and height, and people sometimes misjudge how far it can reach.

Breeding involves an unusual behavior for a snake: the king cobra is the only species known to build an above-ground nest, constructed from dry leaf litter from late March to late May. Most nests sit at the base of trees, reaching up to 55 cm (22 in) high at the center and 140 cm (55 in) wide at the base, typically with a single chamber where the female lays her eggs. Clutch size ranges from 7 to 43 eggs, with 6 to 38 hatching after an incubation period of 66 to 105 days; the female stays near the nest for between two and 77 days to guard it. Hatchlings measure 37.5 to 58.5 cm (14.8 to 23 in) and weigh 9 to 38 g (0.32 to 1.34 oz), and their venom is already as potent as an adult's. The species has also been shown capable of facultative parthenogenesis, reproducing without fertilization through a variation of meiosis. The average lifespan of a wild king cobra is about 20 years.

Range and habitat

The king cobra has a wide distribution across tropical Asia, occurring at elevations up to 2,000 m (6,600 ft) from the Terai region of India and southern Nepal to the Brahmaputra River basin in Bhutan and northeast India, and south through Bangladesh, Myanmar, southern China, Cambodia, Thailand, Laos, and Vietnam, into the maritime Southeast Asian countries of Malaysia, Singapore, Indonesia, and the Philippines. Within India, it has been recorded across the northern hill regions, the northeast, the Eastern and Western Ghats, and parts of the Andaman Islands. It may reach the western edge of its range near Lahore in Pakistan and Palanpur in India; these populations were once thought to result from introduction by snake charmers, but are now considered more likely to be natural, and it remains uncertain whether they persist today.

Conservation status

The king cobra is listed as Vulnerable (VU) and has held that status on the IUCN Red List since 2010. The primary threat named is habitat destruction. The species holds cultural significance as the national reptile of India and has a prominent place in the mythology and folk traditions of India, Bangladesh, Sri Lanka, and Myanmar.