animals world: 2009

The King Cobra (Ophiophagus hannah) is the world's longest venomous snake, with a length that can be as large as 6.7 m (22 ft).[1] This species is widespread throughout Southeast Asia and parts of India, but found mostly in forested areas. Its genus name,Ophiophagus, literally means "snake-eater", and its diet primarily consists of other snakes, including sizeable pythons and even smaller members of its own species. The venom of the King Cobra is primarily neurotoxic, and the snake is fully capable of killing a human with a single bite.[2] The mortality rate from a bite can be as high as 75%.

Profile

The King Cobra is a large and powerful snake, averaging 3.6–4 m (12–13 feet) in length and typically weighing about 6 kg (13.2 lb). A particularly large specimen was kept captive at the London Zoo and grew to 5.7 m (18.8 ft) before being euthanized upon the outbreak of World War II.^[5] The skin is either olive-green, tan, or black and it has faint, pale yellow cross bands down the length of the body. The belly is cream or pale yellow, and the scales are smooth. The head of a mature snake can be quite massive and bulky in appearance, though like all snakes, they can expand their jaws to swallow large prey items. It has proteroglyph dentition, meaning it has two short, fixed fangs in the front of the mouth which channel venom into the prey like hypodermic needles. The male is larger and thicker than the female. The average lifespan of a King Cobra is about 20 years.

Habitat

Widespread, but not common, across South and South-east Asia. It lives in dense highland forests.^[1]^[6] The snake has a preference for living in areas dotted with lakes and streams. King Cobra populations have dropped in some areas of its range due to the destruction of forests, but despite this the snake is not listed by the IUCN as in danger of becoming extinct. It is, however, listed as an Appendix II Animal within CITES

Hunting

King Cobras, like other snakes, receive chemical information (“smell”) via their forked tongues, which pick up scent particles and transfer them to a special sensory receptor (Jacobson's Organ) located in the roof of its mouth.^[1] When the scent of a meal has been detected, the snake will flick its tongue to gauge the prey's direction (the twin forks of the tongue acting in stereo); it will also rely on its keen eyesight (King Cobras are able to detect moving prey almost 100 m [300 feet] away), intelligence^[8] and sensitivity to earth-borne vibration to track its prey.^[9] Following envenomation, the King Cobra will begin to swallow its struggling prey while its toxins begin the digestion of its victim.^[1] King Cobras, as with all other snakes, do not have rigidly fixed jaws. Instead, the jaw bones are connected by extremely pliable ligaments, enabling the lower jaw bones to move independently of each other.^[1] Like other snakes, the King Cobra does not chew its food, instead it swallows its prey whole. The expansion of the jaw enables the snake to swallow prey much larger than its head.^[1]

King Cobras are able to hunt at all times of day, although it is rarely seen at night, leading most herpetologists to classify it as a diurnal species

Diet

The King Cobra's diet is mainly composed of other snakes (ophiophagy): both non-venomous snakes such as pythons and venomous snakes including kraits^[2]^[10] When food is scarce, King Cobras may also feed on other small vertebrates such as lizards, birds, and rodents. In some cases, the cobra may “constrict” its prey, like birds and larger rodents using its muscular body, though this is uncommon.^[1]^[10] After a large meal the snake may live for many months without another one due to its slow metabolic rate.^[1]

The King Cobra's favourite meal is the Ratsnake, which feeds on rats, this leads King Cobras near human settlements as rats are drawn to human settlements, Ratsnakes follow the rats and King Cobras follow the Ratsnakes.

Defense

Adult Male King Cobra

If a King Cobra encounters a natural predator, such as the mongoose, which has some resistance to the neurotoxins,^[12] the cobra will generally try to flee. If all else fails, it will flatten its upper body by spreading its ribs, forming the distinctive cobra hood about its neck, which can be the size of an adult's handspan. It will also emit a high-pitched hiss, sometimes with feigned closed-mouth strikes. These efforts usually prove to be very effective, especially since the King cobra is more dangerous than other mongoose prey as well as being much too

large for the small mammal to kill.

Venom

The King Cobra's venom, which is composed mostly of proteins and polypeptides, is produced in specialized salivary glands (as is the case with all venomous reptiles) just behind the animal's eyes. When biting its prey, venom is forced through the snake's half-inch (1.25 cm) fangs and into the wound. Although its venom is not the most toxic one, a King Cobra's size enables it to inject larger quantities of venom than most other species. On a single bite, it injects as much as 6 to 7 ml of venom.^[13]^[14] The large amount of venom in a single bite allows the King Cobra to kill faster and to kill larger animals than other serpents. The King Cobra can kill up to five times faster than the black mamba, so it just takes a few minutes to kill a human, and it can even kill an Asian Elephant within three hours if the larger animal is bitten in a vulnerable area such as the trunk. ^[15]^[16]

The King Cobra's venom is primarily neurotoxic and thus attacks the victim's central nervous system and quickly induces severe pain, blurred vision, vertigo, drowsiness, and paralysis.^[13] In one to two minutes, cardiovascular collapse occurs, and the victim falls into a coma. Death soon follows due to respiratory failure. There are two types of antivenin made specifically to treat King Cobra envenomations. The Red Cross in Thailand manufactures one, and the Central Research Institute in India manufactures the other; however, both are made in small quantities and are not widely available.^[17] Ohanin, a protein component of the venom, causes hypolocomotion and hyperalgesia in mammals.^[18] Other components have cardiotoxic,^[19] cytotoxic and neurotoxic effects.^[20]

Despite the King Cobra's fearsome reputation and deadly bite, it is a shy and reclusive animal, avoiding confrontation with humans as often as possible.^[10]Monocled Cobra, or Russell's Viper .^[6] There are other venomous snakes within this species' range, in fact, that are responsible for more fatal snake bites than the King Cobra, such as the

In Burma, King Cobras are often used by female snake charmers.^[10] The charmer is usually tattooed with three pictograms using an ink mixed with snake venom; superstition holds that it protects the charmer from the snake.^[10] The charmer kisses the snake on the top of its head at the end of the show

Reproduction

The female king cobra is a very dedicated parent. Before she is ready to lay her eggs, she uses the coils of her long body to gather a big mound of leaf litter. She deposits 20–40 eggs into the mound, which acts as an incubator. The female stays with her eggs and guards the mound tenaciously, rearing up into a threat display if any large animal gets too close.

Inside the mound that the female has built the eggs are incubated at a steady 28℃. When the eggs start to hatch, instinct causes her to leave the nest and find prey to eat so that she does not eat her young.