KING COBRAS: CHARACTERISTICS, BEHAVIOR, VENOM, HUMANS

KING COBRAS

king cobra

King cobras ( Ophiophagus hannah) are the largest and longest venomous snake. They are not common but are found over a wide area in tropical Southeast Asia, India, Bangladesh, Indonesia and the Philippines. Their preferred habitats are forests with dense undergrowth,, mangrove swamps, and forests adjacent to water bodies such as rivers and streams. They are sometimes found around villages and ruined buildings. [Sources: Mattias Klum, National Geographic, November 2001; Desiree Bowie, HowStuffWorks, January 25, 2024; Wikipedia]

King cobras are not a true cobras. They are venomous and have a hood, but belong to a different genus. They were considered to be cobras for a while. In 2007 Wuster, along with other scientists, described how king cobras are a distinct lineage, and arose independently of the "true" cobras in a paper published in "Molecular Phylogenetics and Evolution." While the study focused on the mitochondrial DNA of several different cobra species, this evolutionary divergence is also reflected in morphology and diet. After this king cobras were regarded as the sole members of their own genus, Ophiophagus. Ophiophagus is now considered a species complex. Differences in patterns, colors and other characteristics often found in a particular area may cause the genus to be split into at least four species, spread across its large geographic range. King cobras are sometimes referred to by their old common name "hamadryad", especially in older literature when their scientific name was Hamadryas hannah.

King cobras are threatened in may parts of their range. They are listed as "Vulnerable" by the International Union for Conservation of Nature (IUCN) Red List. King cobras are threatened by habitat loss resulting from deforestation, forest fragmentation, agricultural expansion and urban development as well as the illegal wildlife trade. Biologist Wolfgang Wuster of the University of Wales told National Geographic, “King cobras don’t adapt well to heavily cultivated areas like rice fields. So if the forests go, so do the kings.”

King cobras are sometimes hunted for their skin, used in traditional medicines and painkillers. Their loss disrupt the ecological balance of the places where they live. Conservation efforts include habitat protection and restoration, research on their ecology and behavior and publci awareness campaigns to reduce fear of the snakes and teach people how to coexist with them. International and local laws aim to help king cobras against threats presented by poaching and the illegal wildlife trade.

King Cobra Characteristics

King cobra average three to five meters (10 to 16 feet) in length and can rear up to height of a man. According to Wikipedia the longest known king cobra measured 5.85 meters (19.2 feet) and the largest was 5.6 meters (18 ft 4 in) long and captured in Thailand. According to the Guinness Book of Records, an 18-foot-2-inch specimen was captured in Malaysia in 1937. It later grew to 18 feet, 9 inches at the London Zoo. King cobras in captivity have lived to the age of 25. Their average lifespan in the wild is about 20 years.

scales of a king cobra

King cobras are olive-green to brownish-black in color on their backs and have a greyish-brown belly. Their throat is orange-yellow with irregular black markings. There are lighter yellow bands or crossbars along their body. Their scales are made of keratin (the same material in human fingernails in hair and rhino horn).

King cobras have broad, elongated heads with prominent jaws. The head is black on the back with four white cross-bars. The ventral part of head is white. They also have distinctively large, prominent nostrils, which may aid in their sense of smell. When their hood is open it displays a pattern resembling a pair of spectacles. Unlike true cobras, which have short, wide hoods, king cobras have a long narrow hood.

King cobras have a rounded muzzle and black tongue black. It has two fangs and 3–5 maxillary teeth in the upper jaw, and two rows of teeth in the lower jaw. The nostrils are between two shields. The large eyes have a golden iris and round pupils. Its hood is oval shaped and covered with olive green smooth scales and two black spots between the two lowest scales.

King Cobra Behavior and Communication

Like other snakes, a king cobra receives chemical information via its forked tongue, which picks up scent particles and transfers them to a sensory receptor (Jacobson's organ) located in the roof of its mouth. King cobras are good swimmers, often living near water. They are generally solitary, shy and retreating and only aggressive if provoked, threatened or cornered. They are considered diurnal because they hunt during the day, but they have been seen at night, rarely.

When threatened or agitated, king cobras spread their distinctive hood by extending their ribs and skin and raises the front third of their body off the ground — allowing to reach a height of 1.5 meters. Hood spreading and rearing up to a vertical stance are warning displays. King cobras also make a deep, loud "hiss" resembling a growl when threatened.

The growl-like hiss of king cobras is deeper and more guttural than other snake species due to the snake's large size and unique respiratory system, which enables it to produce a lower-pitched and more resonant sound. Hissing serves as a method of warning and of intimidation and is often used in conjunction the cobra's flared hood and raised body. Hissing also appears be a form of communication used in courtship rituals, territorial disputes or other social interactions with other cobras.

King Cobra Diet and Hunting

king cobra range

While other cobras and many snakes in general mainly consume rodents and amphibians, and consume snakes only occasionally, king cobras often feed on other snakes almost exclusively. King cobras preys on both venomous and nonvenomous snakes. They are known in some circles as the "snake-eater". They are particularly fond of Asian rat snakes and pythons. Their diet can include members of their own species especially when other food sources are scarce. They also consume other reptiles, such as lizards, and occasionally small mammals.

Prey they have been observed include Indian cobras, banded kraits, rat snakea, pythons, green whip snakes, keelbacks, banded wolf snakes and Blyth's reticulated snakes. It has been documented hunting Malabar pit vipers and hump-nosed pit vipers by following their odour trails. In Singapore, one was observed swallowing a clouded monitor lizard.

King cobras do not spit venom, instead they rely on their size, cunning and deadly venom for protection from predators. When they strike they often do so downward. When hunting they rely on their potent venom to immobilize prey quickly. The venom not only incapacitates prey it also so breaks down tissue and starts the digestive process when prey is outside the snake's body.

King cobras sometimes charge and are capable of striking at a considerable range. Their large size allows them to overpower other snakes. In some cases, the cobra constricts its prey using its muscular body, though this is uncommon. Following envenomation, they swallow their prey whole. Because of their flexible jaws, they can swallow prey much larger than their head. After a large meal, it may go for many months without another one because of its slow metabolic rate.

King Cobra Reproduction

Outside of breeding periods, males are solitary animals engaged in hunting, surviving and occasionally defending their territory. But during breeding season they become very territoriality and increasing aggressive. They sometimes engage in ritualistic combat with rival males — a dramatic event involving intertwining and wrestling to establish dominance — primarily for mating rights. This combat is more a display of strength than a battle to the death. King cobras are capable of facultative parthenogenesis (reproduce asexually in certain circumstances).

king cobra nest made of pine needles in Kumaon, Uttarakhand, India, with female king cobra lying on top of the nest (Picture by K.S. Sajwan)

On the male king cobra "combat dance," Desiree Bowie wrote in HowStuffWorks: During this nonlethal but physically demanding ritual, two males will rise, elevating the upper part of their bodies, and entwine themselves around each other. This display is not about biting but rather pushing and shoving; each snake attempts to overpower the other by pushing its rival's head to the ground. The goal is to demonstrate physical superiority without resorting to actual violence or the use of venom. The victorious male earns the right to mate with the female in the area.

Female king cobras are the only snakes known to build a nest for their eggs. They lay approximately 20 to 50 eggs, and the incubation takes around 60 to 80 days. Unlike most reptiles, king cobras are at least temporarily monogamous stay with their eggs until they are hatched and viciously defends them. Females build a a nest from leaf litter and both sexes defend the territory around it.

Females typically build a nest from late March to late May. Most nests are located at the base of trees, are up to 55 centimeters (22 inches) high in the centre and 140 centimeters (55 inches) wide at the base. They consist of several layers and most of the time have one chamber, into which females lay their eggs. Temperature inside nests are not always the same but varies depending on elevation from 13.5 to 37.4°C (56.3 to 99.3°F).

The eggs are vigilantly guarded until they are close to hatching. After the hatchlings emerge, the female typically departs, leaving the young to fend for themselves. Between 20 and 40 hatchlings are born, already outfit with poison. Hatchlings are between 37.5 and 58.5 centimeters (14.8 and 23 inches) long and weigh 9 to 38 grams (0.32 to 1.34 ounces) at birth. Their venom is as potent as that of the adults. Juveniles are darker than adults, which are plain brown. Young snakes also have dark chevrons running down their backs. They may be brightly marked, but these colors often fade as they mature. Juveniles are alert and nervous, and can be highly aggressive if disturbed.

King Cobra Venom

King cobras produces large amounts of a potent venom. A fully grown King Cobra can deliver enough venom to kill a full grown Asian elephant in three hours. They inject venom through relatively small fangs (about ten millimeters long) and are capable to injecting more venom than any other snake expect the Gabon viper.

king cobra skull

King cobra venom contains potent neurotoxins that disrupt the nervous system and cardiotoxins that affect the the heart but it is not the most powerful venom among venomous snakes. What makes king cobras so potentially dangerous is the large amount of venom they can inject in a single bite.

It has been reported that cytotoxicity (tissue killing capacity) of king cobra venom varies significantly, depending upon the age and locality of an individual. Clinical cardiotoxicity is not widely observed, nor is nephrotoxicity present among patients bitten by this species, presumably due to the low abundance of the toxin. King cobra contains a lot of metalloproteinases (SVMPs) — accounting for 11.9 percent to 24.4 percent of total venom protein, much more than that of most cobras which is usually less than one percent. This protein family includes principal toxins responsible for vasculature damage and interference with haemostasis, contributing to coagulopathy (impairing the blood's ability to clot, resulting in excessive bleeding or clotting).

King Cobra Bites

King venom causes rapid swelling, dizziness, severe pain, blurred vision, vertigo and drowsiness and can cause loss of consciousness, difficulty breathing, erratic heart-beat, paralysis and respiratory failure. The mortality rates depends on the amount of venom taken in by the victim. Most bites involve non-fatal amounts. Surviving a king cobra bite is highly dependent on receiving prompt medical attention. If antivenom is administered quickly after the bite, the chances of survival significantly increase. If not treated quickly a king cobra's bite lead to respiratory failure and death.

Local symptoms include dusky discolouration of skin, edema and pain; in severe cases, swelling extends proximally, with necrosis and tissue damage that may require amputation. Onset of general symptoms follows while the venom is targeting the victim's central nervous system, resulting in blurred vision, vertigo, drowsiness, and eventual paralysis. If not treated promptly, it may progress to cardiovascular collapse

Polyvalent antivenom of equine origin is produced by Haffkine Institute and King Institute of Preventive Medicine and Research in India. A polyvalent antivenom produced by the Thai Red Cross Society can effectively neutralise venom of the king cobra. In India and Thailand, a concoction (or liquid blend) of turmeric (Curcuma longa) and other potent, medically relevant herbs has been reported to be affective against the venom of the king cobra when ingested.

King Cobras and Humans

The king cobra is featured in the mythology, practices and folklore of groups of people in India, Bangladesh, Sri Lanka and Myanmar. A ritual in Myanmar involves a king cobra and a female snake charmer. The charmer is a priestess who is usually tattooed with three pictograms and kisses the snake on the top of its head at the end of the ritual. Members of the Pakokku clan tattoo themselves with ink mixed with cobra venom on their upper bodies in a weekly inoculation that they believe would protect them from the snake, though there no scientific evidence that this is true. The king cobra is regarded as the national reptile of India. Some Indians believe king cobras possess exceptional memory; according to a myth, the killer of a king cobra stays in the eyes of the snake as an image, which is later picked up by the snake's partner and used to hunt down the killer for revenge. Because of this myth, whenever a cobra is killed especially in India, the head, if not the entire body, is either crushed or burned to destroy the eyes completely.

In October 2019, a four- meter (13-foot) king cobra was pulled from a sewer in southern Thailand in an hour-long operation,. AFP reported: “Footage of the daring capture showed a man chasing the cobra into a dark and cramped drainage pipe. The cobra splashed around in water and tried to slither back into the pipe, but was pulled out by the tail after multiple attempts. [Source: AFP, October 15, 2019]

“A security guard on the housing estate where it was found first alerted the rescue group that caught the snake.“"Seven rescue workers, including me, went there," said Kritkamon Kanghae, 26, adding that the estate was built on a plot that was once jungle. Kritkamon said the snake was more than four meters long, weighed 15 kilos (33 pounds), and was the third-largest they had found. It was later released into the wild.

King Cobra Boxing and Kissing

Snake charmer shows in Myanmar often feature king cobras caught in the Mt. Popa region. The snakes are up to 15 feet long and as thick as a man's arm. During the climax of their shows, a snake charmer kisses the cobra on the mouth. Some snake handlers claim that gently kissing a cobra calms them. One handler told National Geographic, “I know I have mastered the snake when I can touch it with my lips.” The photographer Mattias Klum wrote: the handler “had a way of calming it, slowly following its movements so he could reach out and caress its head. Finally he leaned in for the kiss.”

Ban Khok Sa-nga in northeastern Thailand used to be famous for its king cobra dishes until they were banned. Now it is known for its live cobra shows. “Boxing matches” are staged between king cobras and people, with the human participants earning a few coins, showing of off their manliness and attract buyers for herbal medicines and snake bite cures. Women in the King Cobra Club charge 25 cents a head to let tourist watch them dance with king cobra heads on their mouth.

King Cobra Attacks

There have been few reported human attacks by king cobras in part because the snakes generally avoid human contact and prefer dense forests. They are s not considered aggressive and usually slinks off when disturbed, but they are known to be aggressive when defending incubating eggs and attack intruders rapidly. They can also be easily irritated by closely approaching objects or sudden movements. When raising its body, the king cobra can still move forward to strike with a long distance, and people may misjudge the safe zone. It can deliver multiple bites in a single attack. Their venom of juveniles is as potent as that of the adults. Juveniles are alert and nervous, and can be highly aggressive if disturbed.

In October 1999, Associated Press, reported: “An Eastern Kentucky man bitten by a 15-foot king cobra lived to tell the tale, but the snake wasn't so lucky. Jim Harrison, director of the non-profit Kentucky Reptile Zoo in Slade, was hospitalized. He was bitten on the thumb while treating the snake for pneumonia. The snake, lacking medical assistance while Harrison was at the University of Kentucky Hospital, died. The snake did not have a name. Harrison's bite is the 37th by a king cobra recorded in the world and the fifth in the United States, said Dr. Barry Gold, an assistant professor at Johns Hopkins University School of Medicine in Baltimore. Gold is a consultant to zoos, aquariums and poison centers about snake bites. [Source: Kimberly Hefling, Associated Press, October 28, 1999]

About one-third of the reported king cobra bites were fatal, Gold said. Harrison said this is the 12th time he's been bitten by a snake, but the first time by a king cobra. "I'd rather talk about the times I've not been bitten than the times I have been bitten,'' he said. Harrison said he was fortunate in that he had plenty of antivenin on stock. "Without antiserum and being prepared, I would've been dead,'' he said. Harrison took his own supply of antivenin with him to Lexington. Gold was contacted, and advised physicians in Lexington about how much antivenin to give Harrison. Harrison's symptoms included blurred vision, problems with numbness in his face, difficulty moving his tongue, severe headache and crushing chest pain, Gold said. "Those were all symptoms to indicate he had sustained poisoning from the venom,'' Gold said.

Harrison was intravenously given 15 vials of antivenin. One day later, he walked out of the hospital, but could suffer side effects from the antivenin such as a rash. The Kentucky Reptile Zoo has about 1,500 snakes many of which are on display outside Natural Bridge State Resort Park. Researchers worldwide regularly purchase venom from the zoo for research of several diseases. It is also used in the production of antivenin for poisonous bites. Harrison said the problem now is that without the king cobra, the zoo has a big female cobra that no longer has a mate for the breeding season in February and March. "We're trying to find her a boyfriend,'' he said.

In October 2022, a 2.2-meter (7 foot) king cobra that escaped from its home in a Swedish zoo returned back home by itself after a week. Associated Press reported: The deadly snake, whose official name is Sir Vass (Sir Hiss), escaped ovia a light fixture in the ceiling of its glass enclosure at the aquarium, part of the zoo at the Skansen open-air museum and park on Stockholm’s Djurgarden island. As a result of an intensive search with X-ray machines, “Houdini” was located earlier this week in a confined space near the terrarium in the insulation between two walls. Holes were drilled into the walls where the snake was hiding but the cobra disappeared from the view of the X-ray cameras in the early Sunday. It turned out the snake had given up its freedom ride and crawled back to its terrarium. “It was too stressful for Houdini with all the holes in the walls, so he wanted to go home again,” a zoo official told SVT. The park said the snake wouldn’t have survived the cold climate if had gotten out of the building. [Source: Associated Press, October 30, 2022].

King Cobra Alert in the Philippines

Reporting from Bansalan, Davao Del Sur, Orlando B. Dinoy wrote in the Philippine Daily Inquirer: “King cobras, which are not endemic in this town, have suddenly appeared and even started attacking humans, officials said. Since the start of the month, two farmers have already been killed by king cobras while a baby was spared because his parents were quick enough to parry the attack. [Source: Orlando B. Dinoy, Philippine Daily Inquirer, February 27, 2010]

Insp. Reyniel Raotraot, deputy chief of police, said the first victim was Alvin Ayuda, 28, a farmer in Barangay Tinungtongan. Raotraot said Ayuda was cutting trees in his backyard with two friends when the reptile attacked and bit him. Raotraot said Ayuda’s friend ran after the snake which also tried to strike him. Ayuda reached home and told his family that he was bitten by a snake. He died shortly without medication.

Raotraot said the second victim was Raul Oguit, 32, of Barangay Managa here. Relatives brought him to a hospital but he died on the way, he said. Raotraot said a king cobra found its way into the house of a family here and was seen near a sleeping baby. Raotraot said the baby’s father threw a rug at the snake to drive it away, but the snake wrestled with it. The baby’s parents struck the snake dead with a piece of wood.

Later, residents of Barangay Tinungtongan killed another king cobra. two days after that, residents of Barangay Sibayan here also killed a king cobra, which was trying to cross the highway to their homes. All the snakes were suspected to be mature because their lengths exceeded two meters, Raotraot said. Raotraot said the snake attacks were alarming.

Chief Insp. Solomon de Castilla, Bansalan police chief, said police have launched an information drive on how to avoid being bitten by snakes. “Presence of mind is important and a person must have courage to kill them if he can’t avoid being bitten,” he said. Raotraot said police also advised residents to clean their backyards to remove possible hiding places of snakes. Government veterinarian Fermin Verallo said king cobras are not endemic to the province. He said king cobras were only previously seen in Davao Oriental and their entry here could be due to the intense heat brought about by El Niño. Verallo also said there are no available anti-venoms in the province and that victims have to be brought to Davao City to receive medication.

Image Sources: Wikimedia Commons

Text Sources: Animal Diversity Web animaldiversity.org ; National Geographic, Live Science, Natural History magazine, David Attenborough books, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Discover magazine, The New Yorker, Time, Reuters, Associated Press, AFP, Lonely Planet Guides, CNN, BBC, Wikipedia, The Guardian, Top Secret Animal Attack Files website and various books and other publications.

Last updated February 2025