Basic Information
Scientific Name: Varanus komodoensis
Alternative Name: Komodo monitor, ora [1]
Distribution: Southeastern Indonesian islands, including Flores, Gili Motang, Komodo, and Rinca [1]
Habitat: Hot, arid grasslands, savannas, and monsoon forests [1]
Activity: Arboreal as Juveniles; [14] live primarily in the lowlands as adults [1]
Average Size: 8 - 10 ft. (2.5 - 3.1m) [3]
About the Komodo Dragon
The Komodo Dragon is the largest and heaviest extant lizard in the world. [3] It is ectothermic, relying on external heat and cooling sources for thermoregulation. [5] Current population of the Komodo dragon remains stable, keeping around five thousand individuals. [2] Most reptiles have changed little since the days of the dinosaurs, but the Komodo Dragon is, relatively speaking, a new arrival. [4] Its closest relatives are the beaded lizards: Guatemalan Beaded Lizard and the Gila Monster. [5] Despite stories of the dangerous lizard, the existence of Komodo Dragons was not confirmed until the early 1900s. [2]
Komodo Dragons exhibit intelligent behavior. [17] As juveniles, they live an arboreal existence until they are too heavy to climb trees. [2] Komodos demonstrate playful behavior even into adulthood. [17]
Komodo Dragons are excellent swimmers, [2] which allows them to travel between islands when they need to search for food. [1] They can dive to depths of up to 15 ft. (4.6 m). [16] Komodos use their tails for propulsion, [1] and they hunt in the surf for fish, birds, and even crabs. [2]
Komodos have a reputation as human killers. Some say this is well deserved because they do not exhibit fear of humans and because they will attack when provoked. [2] However, few confirmed reports of death-by-Komodo exist. Still, any person that is near living Komodos must be very cautious and be vigilant for signs of aggression. Signs of aggression include the following: puffing out of the throat, hissing, trashing of the tail, and a semicircular stance. [1] Park Rangers carry long poles with forked ends. Should a Komodo come too close, the Ranger will poke them in the nose. [15]
Reproduction
The Komodo Dragon mating season runs from May to August of each year; [11] a Komodo matures sexually between the ages of five and seven. [1] While some Komodos have reproduced parthenogenetically, [12] the majority of Komodo reproduction takes place during the mating season.
Males fight for territory and mating partners. They fight by standing on their hind legs, balancing on their tails, and they wrestle each other. [12] The goal is to push the opponent to the ground; sometimes the loser incurs broken or dislocated limbs. [12]
After mating, six to eight weeks later, the female digs nest chambers [9] and lays a clutch of fifteen to thirty eggs. [1] Generally, this happens in the months of July, August, and September. Females rarely guard the nests, but sometimes they will dig mazes to confuse egg thieves. [1]
The eggs are smooth and oval, approximately 2 in. (5 cm) by 4 in. (10 cm). They incubate for eight to nine months, leaving them to hatch around April. [1]
Life Cycle
Baby Komodo Dragons use their egg tooth to rip through the shell. [13] They can be 10 - 22 in. (25 - 56 cm) long and weigh around 3.5 oz. (99 g). [1] The average hatchling is about 14 in. (35.6 cm) long. [13]
Immediately after hatching, the Komodos must flee to the trees, where their camouflage protects them. [14] Many of them don't make it to the trees; they fall prey to birds, snakes, or even other Komodo Dragons. [14] For four to five years, Komodos live an arboreal lifestyle, only coming down to find water, which can be an extremely dangerous task for a young Komodo. [14]
Each year, a young Komodo grows approximately 1 ft. (30.5 cm) a year for the first four to five years of its life. [14] Komodos continue to grow throughout their life span, but after the fifth and sixth year, they grow much more slowly. [14] As soon as a Komodo reaches 4 ft. (1.2 m) long, they become too heavy for an arboreal life style and must switch to the adult, terrestrial life style of the adult Komodos. [14]
Komodo Dragons that make it to adulthood may life up to fifty years in the wild; [11] whereas, in captivity, most Komodos only live to twenty-five. [1]
Hunting and Diet
Juveniles primarily feed on insects, eggs, and small birds. [14] Adult Komodos are carnivores and will devour any animal they can, which includes Sunda deer, birds, snakes, fish, crabs, snails, small mammals, pigs, water buffalo, eggs, wild horses, and younger Komodos. [2] Some believe that they even hunted the now-extinct pygmy elephant. [3]
A mature Komodo Dragon has no natural enemies [6] because they are formidable predators, hunting large mammals, such as pigs, deer, horses, and buffalo. [3] Komodos have powerful claws and a surprisingly quick attack; [1] they ambush large prey after lying in wait. [3] They can chase prey up to 13 miles (21 km) per hour for short stretches. [7]
Komodo Dragons are known carrion eaters, scavengers, [1] but they will hunt live prey, too. [2] When a Komodo Dragon bites down, its gums contribute to swallowing. Since the gums cover most of its teeth, they tear and bleed. The blood combines with its saliva to make a kind of slime that enables the Komodo to swallow food whole without chewing. [7]
Fitted with sixty flat, saw-like teeth, [6] an adult Komodos grow as many as two hundred new teeth each year and continue to grow, [1] just more slowly than juveniles.
Komodo Dragons cannot lap or gulp water; [8] instead, a Komodo will scoop a mouthful of water and tilt its head back, allowing the water to flow down its throat. [9] Komodos can go for long periods without water; some adults can go up to nine months without drinking. [10] This is because they can extract about eighty percent of the water needs from their prey's flesh. [1]
On average, an adult needs to eat about one large prey (i.e. one Sambar deer or water buffalo per month). [10] Like most reptiles, though, Komodos have a low resting metabolic rate, enabling them to survive when food becomes scarce. A large adult can survive with as little as 1 lbs. (0.45 kg) of food per day, [1] and a Komodo can eat up to eighty percent of its own body weight in a single meal. [10]
Bacteria or Venom
Much confusion exists over the Komodo Dragon's bite. For a long time, it was believed that the bacteria in its saliva caused a slow, painful death via infection. However, recent research has proven that Komodos also have glands that release venom with hemorrhagic and other toxins that poison the prey. [18]
The confusion arose because the bacteria in its saliva and between its teeth are highly dangerous and quickly cause infection to other animals bitten by a Komodo. [1] The bacteria also inflict rapid weakness in bitten prey, [3] and the bacteria are more powerful than that found in carrion, which enables the Komodo Dragon to scavenge and digest carrion without issue. [7]
On top of the hazardous bacteria, the Komodo Dragon has glands in its mouth that release venom; this causes the prey to continuously bleed. [6] The bleeding both weakens the animal and enables the Komodo to track it, should it escape the initial attack. [3] Anything bitten by a Komodo Dragon dies a slow, painful death. [6]
Special Senses
Komodo Dragons have a specialized forked tongue and a Jacobson's organ. [5] The tongue collects chemicals from the environment then rubs them into pads found at the bottom of the Komodo's mouth. These send signals to the Jacobson's organ, a part of the nasal system, which sends messages to the brain. [5]
Since their epidermis is covered with thick, tough scales for protection, Komodos have special sensory plaques to help them feel their environment. Each scale is connected to a tiny sensory plaque organ by a nerve. The scales on the facial area and the soles of the feet of a Komodo have three times as many plaques than the rest of the body. [6]
Like most reptiles, Komodos don't have the chest muscles necessary for respiration while running. Instead, they have a bony pouch in the throat called a gular pouch, which is filled with air. [8] The pouch pumps air into the lungs, allowing them to pursue prey at a sprint for short distances without breathing. [8]
Physical Description
Juveniles and Adults are different in appearance. [3]
As hatchlings and young Komodos, they have a multicolored epidermis, containing brown, yellow, orange, and red. [1] Juveniles also have a pattern of black and white speckles, stripes, and bands; all of this camouflages them in the trees an enables them to survive. [1]
Adults have a far more drab appearance. [3] They are mostly black, green, or grey with patches of yellow, brown, or white. [1]
Adult Komodo Dragons have a massive body and sturdy legs. [3] They have broad, powerful heads [3] with eyelids to protect their eyes and ear openings covered by a flap of skin, on either side of their heads. [9] They have long, forked tongues. [3]
Males commonly grow up to 9 ft. (2.75 m) long and can weight over 200 lbs. (90 kg); some very large males weigh in at 275 lbs. (125 kg). [1] The current record for a male Komodo Dragon is over 10 ft. (3.1 m) long. [1] Females tend to be smaller, growing to lengths of 7.5 ft. (2.3 m) and weigh in at 150 lbs. (67.5 kg). [1]
Footnotes
- Komodo Dragon
- Endangered in the Wild: Komodo Dragon
- O'Shea [Reptiles] 98
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- Fry, 'A central role for venom in predation by Varanus komodoensis (Komodo Dragon)...'
For more information on footnotes and references, please see the bibliography.
