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Lifespan, longevity, and ageing

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Maximum longevity: 25 years (captivity) Observations: Little is known about the lifespan of the Komodo dragon. They appear capable of living at least 25 years in captivity (http://www.zoo.org/). Anecdotal reports of animals living up to 50 years in the wild are plausible but remain unverified.
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Behavior

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Although Varanus komodoensis can see 300 meters away and can hear a restricted range of sound, its sense of smell is its primary method for detecting food and the tip of its tongue is its primary scent detector. Males communicate dominance in mating and feeding order by wrestling in upright positions. Females give off a scent in their feces to communicate that they are ready to mate and the male replies by rubbing his chin on her and licking her body.

Communication Channels: visual ; tactile ; chemical

Other Communication Modes: pheromones

Perception Channels: visual ; tactile ; acoustic ; chemical

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Lawwell, L. 2006. "Varanus komodoensis" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Varanus_komodoensis.html
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Leanne Lawwell, Kalamazoo College
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Ann Fraser, Kalamazoo College
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Tanya Dewey, Animal Diversity Web
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Associations

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Adult Komodo dragons are at the top of their food chain and do not have any predators. Juveniles often fall prey to adults, larger mammals, and birds. They avoid predation by being arboreal until they become larger.

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Lawwell, L. 2006. "Varanus komodoensis" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Varanus_komodoensis.html
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Leanne Lawwell, Kalamazoo College
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Ann Fraser, Kalamazoo College
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Tanya Dewey, Animal Diversity Web
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Morphology

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Komodo dragons are the largest lizards, reaching 165 kg and greater than three meters in length. Juveniles are green with yellow and black bands. Adults dull and uniform in color, from brown to grayish red. Their robust bodies are uniformly covered in rough scales. They have strong limbs and a powerful, muscular tail. The heads of Komodo dragons have a rounded snout and ear openings. Their skulls are flexible and have sharp, serrated teeth. Although males tend to grow larger, there are no obvious morphological differences between the sexes.

Range mass: 165 (high) kg.

Range length: 3.1 (high) m.

Other Physical Features: heterothermic

Sexual Dimorphism: male larger

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Lawwell, L. 2006. "Varanus komodoensis" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Varanus_komodoensis.html
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Leanne Lawwell, Kalamazoo College
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Ann Fraser, Kalamazoo College
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Tanya Dewey, Animal Diversity Web
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Life Expectancy

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Although many Varanus komodoensis individuals fall prey to other animals as hatchlings, ones that live to adulthood usually have a lifespan of around 50 years.

Average lifespan
Status: wild:
50 years.

Average lifespan
Sex: female
Status: captivity:
8.9 years.

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Lawwell, L. 2006. "Varanus komodoensis" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Varanus_komodoensis.html
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Leanne Lawwell, Kalamazoo College
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Ann Fraser, Kalamazoo College
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Tanya Dewey, Animal Diversity Web
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Habitat

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Adult Komodo dragons live mainly in tropical savannah forests. They prefer open lowland areas with tall grasses and bushes, but are also found in other habitats, such as beaches, ridge tops, and dry riverbeds. Young Komodo dragons are arboreal and live in forested regions until they are eight months old.

Range elevation: 0 to 820 m.

Habitat Regions: tropical ; terrestrial

Terrestrial Biomes: savanna or grassland ; forest

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Lawwell, L. 2006. "Varanus komodoensis" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Varanus_komodoensis.html
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Leanne Lawwell, Kalamazoo College
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Tanya Dewey, Animal Diversity Web
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Distribution

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Varanus komodoensis is found only in the lesser Sunda region of the Indonesian archipelago, including the islands of Komodo, Flores, Rinca, and Padar.

Biogeographic Regions: oriental (Native )

Other Geographic Terms: island endemic

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Lawwell, L. 2006. "Varanus komodoensis" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Varanus_komodoensis.html
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Leanne Lawwell, Kalamazoo College
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Ann Fraser, Kalamazoo College
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Tanya Dewey, Animal Diversity Web
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Trophic Strategy

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A normal adult Komodo dragon diet consists mainly of carrion, but it is not uncommon for them to attack and eat a variety of large prey, including goats, pigs, deer, wild boar, horses, water buffalo, and smaller Komodo dragons. Komodo dragons hunt larger prey by ambushing them and delivering a bite. They then follow the injured animal until they succumb to either blood loss or infection. The saliva of Komodo dragons is rich in bacteria that rapidly leads to infection in their prey. A recent discovery of venom in the bites of Varanus species implies that venoms may be used in subduing prey also, although specific research on Komodo dragon venom action has not been completed. Juveniles feed on grasshoppers, beetles, small geckos, eggs, birds, and eventually small mammals. Varanus komodoensis is able to swallow large pieces of food by expanding its throat and its flexible skull. They eat most of their prey, leaving very little to be wasted.

Animal Foods: birds; mammals; reptiles; eggs; carrion ; insects

Primary Diet: carnivore (Eats terrestrial vertebrates, Scavenger )

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Lawwell, L. 2006. "Varanus komodoensis" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Varanus_komodoensis.html
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Leanne Lawwell, Kalamazoo College
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Ann Fraser, Kalamazoo College
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Tanya Dewey, Animal Diversity Web
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Associations

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Varanus komodoensis is a top predator in its habitat and one of the largest animals present in the area. It is also a scavenger that eats recently dead animals and removes them from the landscape.

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Lawwell, L. 2006. "Varanus komodoensis" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Varanus_komodoensis.html
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Leanne Lawwell, Kalamazoo College
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Benefits

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Komodo dragons are an important ecotourism draw. Scientists are also conducting studies on how they are able have strains of lethal bacteria living in their saliva without being affected by them.

Positive Impacts: ecotourism ; research and education

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Lawwell, L. 2006. "Varanus komodoensis" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Varanus_komodoensis.html
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Leanne Lawwell, Kalamazoo College
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Ann Fraser, Kalamazoo College
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Benefits

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Varanus komodoensis individuals have been known to attack and kill humans in a few rare occurrences. They also have attacked and harmed livestock in the area.

Negative Impacts: injures humans

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Lawwell, L. 2006. "Varanus komodoensis" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Varanus_komodoensis.html
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Leanne Lawwell, Kalamazoo College
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Tanya Dewey, Animal Diversity Web
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Life Cycle

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Varanus komodoensis hatches from eggs. Young Komodo dragons live in trees to avoid falling prey to older members of the species. They are also much smaller and more sinuous than the adults, allowing them to live in trees. At 8 months, they grow too large to be arboreal, alter their diet, and become terrestrial.

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Lawwell, L. 2006. "Varanus komodoensis" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Varanus_komodoensis.html
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Leanne Lawwell, Kalamazoo College
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Ann Fraser, Kalamazoo College
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Tanya Dewey, Animal Diversity Web
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Conservation Status

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Komodo dragons are currently classified as endangered throughout their range. This status is the result of a combination of prey depletion, poaching, and habitat encroachment by humans.

US Federal List: endangered

CITES: appendix i

IUCN Red List of Threatened Species: vulnerable

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Lawwell, L. 2006. "Varanus komodoensis" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Varanus_komodoensis.html
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Leanne Lawwell, Kalamazoo College
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Tanya Dewey, Animal Diversity Web
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Reproduction

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Males engage in a ritual combat to mate with females. They wrestle in an upright position to try to throw the loser to the ground, often drawing blood. When ready to mate, females give off a scent in their feces that males can detect. Male Komodo dragons then locate the female, rub their chin on her head, scratch her back, and lick her body. If the female exhibits interest, she licks him back. He then grasps her with his claws, lifts her tail with his, and mates with her. After mating, some males will stay with the female for a few days to prevent other males from mating with her.

Mating System: polygynandrous (promiscuous)

The mating season of Varanus komodoensis occurs yearly in July and August. Females lay up to thirty eggs about a month later (September) to avoid the hot summer months and allow a chance for a second mating. The eggs are buried in the earth and take about 8 months to hatch. Hatchlings are about 37 centimeters long and have a high mortality rate, frequently falling prey to adults and other species. As a result, they move to nearby trees as soon as they are able. It is estimated that females reach sexual maturity after 9 years and males reach it after 10 years.

Breeding interval: Varanus komodoensis breeds once yearly, but females will often mate more than once to ensure that their eggs are fertilized.

Breeding season: Breeding occurs from July to September.

Range number of offspring: 30 (high) .

Average gestation period: 8 months.

Average age at sexual or reproductive maturity (female): 9 years.

Average age at sexual or reproductive maturity (male): 10 years.

Key Reproductive Features: iteroparous ; seasonal breeding ; sexual ; oviparous

Average birth mass: 100 g.

Average gestation period: 49 days.

Average number of offspring: 22.

Average age at sexual or reproductive maturity (male)
Sex: male:
1825 days.

Average age at sexual or reproductive maturity (female)
Sex: female:
1825 days.

Female Komodo dragons dig a nest chamber in the ground for their eggs and cover it with earth and leaves. They then lie on the nest while the eggs are incubating, but there is no evidence of any parental care once the eggs hatch.

Parental Investment: pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Protecting: Female)

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Lawwell, L. 2006. "Varanus komodoensis" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Varanus_komodoensis.html
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Leanne Lawwell, Kalamazoo College
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Ann Fraser, Kalamazoo College
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Tanya Dewey, Animal Diversity Web
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Biology

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Adult Komodo dragons are generally solitary, although groups may gather around a kill. They are powerful predators and their voracious appetite has further fuelled their ferocious image. Both carrion and live prey are consumed; adults ambush deer, water buffalo and wild pigs, and carcasses can be detected from up to 10 km away (2). The large powerful jaws tear at prey and large amounts can be eaten with surprising speed, only a small percentage of the kill is discarded (5). Komodo dragons can eat up to 80% of their own body weight at one time (2). Recent research into the feeding behaviour of the Komodo dragon has shown that it is actually venomous, possessing complex venom glands in its jaw, which excrete a variety of toxic substances that prevent blood clotting and lower blood pressure in its prey. In contrast to the elaborate venom injection system used by snakes, the Komodo dragon's venom is administered relatively crudely, seeping into the large wounds made by the teeth. This means that even if the injured animal escapes, it will rapidly succumb to shock and blood loss induced by the venom. It was previously believed that toxic bacteria found in the Komodo dragon's mouth help to take down prey by infecting bite wounds, leading to fatal blood poisoning. However, studies have indicated that this may not be the case, and that the venom is the main agent by which prey is subdued (6). The mating season occurs between May and June (2); males compete for access to receptive females by wrestling, rearing-up on their hind legs supported by their thick, muscular tail (5). In July and August, females lay and then incubate their clutch of around 25 eggs in depressions dug into the ground (4). Eggs incubate for up to nine months before hatching (2). Juveniles are extremely vulnerable to predation and spend their first year of life in the relatively protected habitat of the trees (7). Young dragons will feed on snakes, lizards and rodents (4).
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Conservation

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Komodo and surrounding islands lie within the Komodo National Park (5). Law has protected these dragons since the 1930s (4), and international trade is prohibited by their listing on Appendix I of the Convention on International Trade in Endangered Species (CITES) (3). An important tourist trade has sprung-up around these spectacular creatures, bringing over 18,000 visitors to the area each year; it is hoped that this economic incentive will help to safeguard the future of these awesome dragons (5).
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Description

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The Komodo dragons are the largest lizards in the world (4), and with their ancient appearance and evocative name they conjure up the stuff of legends. The heavy-set body is long with stocky legs and a long muscular tail; the scaly skin is greyish-brown all over (4). Dragons from the island of Flores however, are earthen-red in colour with a yellow head (2). Juveniles have a more striking pattern with very variable combinations of bands and speckling in yellow, green, grey and brown (4). Komodos have a well-developed sense of smell and their long, forked yellow tongue resembles the mythical, fire-breathing dragons of their name.
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Habitat

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The three islands where Komodo dragons live are all volcanic; they inhabit the lower monsoon forests and savannah up to about 700 metres above sea level (2).
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Range

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Found on the island of Komodo in Indonesia, from which they have received their common name; these dragons are also found on the neighbouring islands of Rinca and Flores (2).
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Status

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Classified as Vulnerable (VU) on the IUCN Red List (1), and listed on Appendix I of CITES (3).
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Threats

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The population of Komodo dragons today is estimated to be a mere fraction of its size 50 years ago (4). Causes of this decline are widespread habitat loss throughout the region, a loss of prey species and hunting (4). No Komodo dragons have been seen on the island of Padar since the 1970s, the result of widespread poaching of the deer that constitute their chief prey source (5).
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Behavior

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Komodo dragons are solitary animals that generally meet only to reproduce and eat. They are primarily diurnal, which means they are most active during the day. They tend to be most active during the wet season. Komodo dragons prefer hot and dry places with open grassland, as well as tropical forests at low elevations. In regards to territorial behavior, there is a dominance hierarchy determined by size and sex. The largest and strongest males get first priority when eating. Males often wrestle in an upright position to determine mating and feeding orders. Hissing is a common vocalization that indicates defensive behavior and is often used during feeding, fighting, and repeatedly by females during mating season (San Diego Zoo, 2016). Additionally, the feces of a female komodo dragon emits pheromones that alert the males that they are ready to mate.

Komodo dragons are quadrupeds and possess the ability to sprint briefly at speeds of up to 20 kph. As a result, its hunting strategy relies primarily on strength and stealth. It is common for them to spend hours in a single spot, waiting for a deer, boar, goat, or other potential prey (Smithsonian National Zoological Park). Komodo dragons act as both predators and scavengers. They have venomous glands packed with toxins that lower blood pressure, cause massive bleeding, prevent clotting and induce shock in prey (National Geographic). When combined with the dragon’s serrated teeth and powerful neck muscles, this leads to huge gaping neck wounds in their prey that weakens and immobilizes them.

Young komodo dragons are exceptional tree climbers, but they tend to lose this ability after a year. It is primarily a defense mechanism to avoid being cannibalized by their mother. As Komodo dragons mature, they begin to transition into a semi-aquatic lifestyle. When hunting, komodo dragons rely heavily on their sense of smell for finding food. This is utilized through scent-detecting glands at the tips of their tongues (Smithsonian National Zoological Park).

Reference

San Diego Zoo Global. 2016. Komodo Dragon. Retrieved on 14 Apr. 2016 from http://animals.sandiegozoo.org/animals/komodo-dragon

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Reproduction

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The sexual maturation of both male and female komodo dragons typically occurs between 5 and 7 years of age. A typical komodo dragon mating season occurs between May and August. Dominant males often engage in wrestling matches in an upright position, balancing on their tails and hind legs in order to determine courtship over a female. The winning wrestler signals the beginning of the courtship by flicking his tongue on a female’s snout and then over the rest of her body (Smithsonian National Zoological Park). Stimulation is both palpable and chemical, through skin gland secretions. Mating occurs very quickly and, due to the female Komodo dragon’s adversarial behavior, males must be able to completely restrain the female to avoid the risk of injury.

A typical Komodo dragon gestation period will last around 9 months. Subsequently, a komodo dragon will lay anywhere between 15-30 eggs in September (Ciofi, 1999).Females will lie on the nests to protect their potential offspring, but they do not care for them after they hatch. In fact, as soon as they hatch, the young will scatter and climb up trees in order to avoid being cannibalized by the mother or other dragons. The hatchlings will weigh less than 3.5 ounces and average only 16 inches in length. They will feed on a diverse diet of insects, small lizards, snakes, and birds. If they make it to five years of age, their chance of survival increases dramatically.

Female Komodo dragons are capable of having “virgin births” or parthenogenesis. This has been observed both in the wild and in captivity. This means that Komodo dragons can reproduce asexually as well as sexually (Yam, 2006). This trait has been observed in varying species of reptiles. Parthenogenesis is extremely rare among vertebrates, occurring in a mere 0.1 percent of all vertebrates. Furthermore, Komodo dragons have a unique variation in their sex determination. The presence of two identical sex chromosomes results in a male komodo dragon, while two different ones results in a female. Komodo dragon gender is determined by incubation temperature. It is believed that the ability to reproduce both sexually and parthenogenetically is a natural response resulting from the Komodo dragon’s isolated habitat. Researchers speculate that this ability enabled female Komodo dragons to establish new colonies when washed up alone on neighboring shores during storms (Yam, 2006).

References

  • Ciofi, C. The Komodo Dragon. 1999. Scientific American 280 (3):84-91
  • Smithsonian National Zoological Park. Komodo Dragon. Web. 14 Apr. 2016 from http://nationalzoo.si.edu/animals/reptilesamphibians/facts/factsheets/komododragon.cfm
  • Yam, Philip. 2006. Strange but true: Komodo dragons show that "virgin births" are possible. Scientific American, 28 Dec. 2006. Retrieved on 14 Apr. 2016 from http://www.scientificamerican.com/article/strange but-true-komodo-d/

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Morphology

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Coming in a variety of colors, such as blue, orange, green, and gray, the Komodo dragon is the largest extant lizard species. Male individuals can weigh up to 100 kg, and can grow up to 3 m (10 feet) in length. The largest individual ever recorded was 3.13 m and weighed 166 kg, although a more common weight is 70 kg. Female individuals are smaller, usually only about 1.8 m (6 feet) in length. Aside from the obvious size difference, there are no major morphological differences between the sexes (National Geographic). Despite their impressive size, they are very small when born, about 0.1 kg. The body of the lizard is long and flat, with short bowed legs. At the end of each leg are long sharp claws, which are used for both hunting and digging nests. The tail of the Komodo dragon is long and powerful (Smithsonian National Zoological Park). Much like snakes, Komodo dragons have a forked tongue they use to “smell.” This tongue is flicked out and tastes the air to detect prey, as well as which direction it is coming from.

While being impressive in size, the most interesting aspect of the Komodo dragon is its mouth. This dragon has a dorsoventrally flattened rostrum, which means it has a long, flat snout and its mouth is filled with long, curved and serrated teeth. The jaw contains several movable joints, such as the intramandibular hinge, which allows the Komodo dragon to open its mouth very wide, and quickly swallow its food (Smithsonian National Zoological Park). Despite its intimidating mouth, the Komodo dragon has a relatively weak bite force compared to other large predators (e.g. saltwater crocodiles, lions, hyenas). This bite force did correlate positively with body size, with larger individuals having a stronger bite but bite force did not correlate with mouth width (D’Amore et al, 2011). The Komodo dragon’s teeth and claws are not its main weapon however. Located within the mandible are glands that secrete powerful venom. This venom acts as both a neurotoxin and an anti-coagulant (Fry et al, 2009). The neurotoxin causes the prey to go into shock, which allows the dragon to rest after hunting without fear of the prey escaping. The anti-coagulant effect will cause the animal to bleed out very quickly, should it manage to escape. The stomach of the Komodo dragon is very accommodating, allowing up to 80% of the animal’s body weight to be consumed (National Geographic).

References

  • D’Amore, D. C., Moreno, K., McHenry, C. R., and Wroe, S. (2011). The effects of biting and pulling on the forces generated during feeding in the Komodo dragon (Varanus komodoensis). PLoS ONE, 6(10): e26226. doi:10.1371/journal.pone.0026226
  • Fry B.G., Wroe S., Matthias T.W., van Oschd J.P., Moreno K., et al. (2009). A central role for venom in predation by Varanus komodensis (Komodo Dragon) and the extinct giant Varanus (Megalania) priscus. Proc Natl Acad Sci 22:8969-8974.
  • National Geographic. Komodo Dragon. Retrieved on 14 Apr. 2016 from http://animals.nationalgeographic.com/animals/reptiles/komodo-dragon/
  • Smithsonian National Zoological Park. Komodo Dragon. Retrieved on 14 Apr 2016 from http://nationalzoo.si.edu/animals/reptilesamphibians/facts/factsheets/komododragon.cfm

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Habitat

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The Komodo dragon is found only on 5 islands in the lesser Sundas region of southeastern Indonesia, including Komodo, Rinca, Gili Motang, Gili Dasami, and Flores (Jessop et al, 2004; San Diego Zoo, 2016). These islands are volcanic in origin, and covered in many habitat types, but mainly forest and savannah. Most of the Komodo dragons live on Komodo Island, from which their name is derived (Jessop et al, 2004). The temperatures during the daytime in the dry season can reach up to 35 degrees Celsius. In addition to these high temperatures, the islands can reach up to 70 percent humidity (San Diego Zoo, 2016).

Komodo dragons live in three main habitat types: coastal mangroves, open savannahs, and fragmented shade forests. Juveniles are typically arboreal, while adult dragons typically are terrestrial (Harlow et al, 2010). Most komodo dragons prefer to live in savannahs with tall grasses and bushes, where they wait to ambush prey, but they are found all across the islands. Other types of habitats they can be found in are beaches and mountaintops. Within their habitats, Komodo dragons build themselves one of three types of nests for living and egg-laying: ground nests, hill nests, or mound nests. Ground nests are deep burrows that are horizontal to the ground. Hill nests are large burrows built into the face of a hill, in one or more tiers. Mound nests are nests that were previously used by other animals (such as orange-footed scrub fowl or other dragons) that have been repurposed by Komodo dragons. These nests tend to be constructed more often within a fragmented deciduous forest than any other type of habitat (Jessop et al, 2004). Upon hatching, komodo dragons are arboreal until about 8 months of age. After 8 months of age, they leave the trees for the ground where they spend most of their time, although they are also excellent swimmers (National Geographic).

References

  • Harlow, H. J., Purwandana, D., Jessop, T. S., and Phillips, J. A. (2010). Body temperature and thermoregulation of Komodo dragons in the field. Journal of Thermal Biology, 35(7), 338–347.
  • Jessop, T. S., Sumner, J., Rudiharto, H., Purwandana, D., Imansyah, M. J., & Phillips, J. A. (2004). Distribution, use and selection of nest type by Komodo dragons. Biological Conservation, 117(5), 463–470.
  • National Geographic. Komodo Dragon. Retrieved 14 Apr. 2016 from http://animals.nationalgeographic.com/animals/reptiles/komodo-dragon/
  • San Diego Zoo Global. 2016. Komodo Dragon. Retrieved on 14 Apr. 2016 from http://animals.sandiegozoo.org/animals/komodo-dragon

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Distribution

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Continent: Asia
Distribution: Komodo, Padar, Rintja, Flores, Lesser Sunda region of Indonesia
Type locality: Komodo Island, Lesser Sunda Islands, Indonesia.
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Komodo dragon

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The Komodo dragon (Varanus komodoensis), also known as the Komodo monitor, is a member of the monitor lizard family Varanidae that is endemic to the Indonesian islands of Komodo, Rinca, Flores, and Gili Motang. It is the largest extant species of lizard, growing to a maximum length of 3 m (9.8 ft), and weighing up to 70 kg (150 lb).

As a result of their size, Komodo dragons are apex predators, and dominate the ecosystems in which they live. Komodo dragons hunt and ambush prey including invertebrates, birds, and mammals. Komodo dragons' group behavior in hunting is exceptional in the reptile world. The diet of Komodo dragons mainly consists of Javan rusa (Rusa timorensis), though they also eat considerable amounts of carrion. Komodo dragons also occasionally attack humans.

Mating begins between May and August, and the eggs are laid in September; as many as 20 eggs are deposited at a time in an abandoned megapode nest or in a self-dug nesting hole. The eggs are incubated for seven to eight months, hatching in April, when insects are most plentiful. Young Komodo dragons are vulnerable and dwell in trees to avoid predators, such as cannibalistic adults. They take 8 to 9 years to mature and are estimated to live up to 30 years.

Komodo dragons were first recorded by Western scientists in 1910. Their large size and fearsome reputation make them popular zoo exhibits. In the wild, their range has contracted due to human activities, and is likely to contract further from the effects of climate change; due to this, they are listed as Endangered by the IUCN Red List. They are protected under Indonesian law, and Komodo National Park was founded in 1980 to aid protection efforts.

Taxonomic history

Skull of a Komodo dragon

Komodo dragons were first documented by Europeans in 1910, when rumors of a "land crocodile" reached Lieutenant van Steyn van Hensbroek of the Dutch colonial administration.[5] Widespread notoriety came after 1912, when Peter Ouwens, the director of the Zoological Museum of Bogor, Java, published a paper on the topic after receiving a photo and a skin from the lieutenant, as well as two other specimens from a collector.[4]

The first two live Komodo dragons to arrive in Europe were exhibited in the Reptile House at London Zoo when it opened in 1927.[6] Joan Beauchamp Procter made some of the earliest observations of these animals in captivity and she demonstrated their behaviour at a scientific meeting of the Zoological Society of London in 1928.[7]

The Komodo dragon was the driving factor for an expedition to Komodo Island by W. Douglas Burden in 1926. After returning with 12 preserved specimens and two live ones, this expedition provided the inspiration for the 1933 movie King Kong.[8] It was also Burden who coined the common name "Komodo dragon".[9] Three of his specimens were stuffed and are still on display in the American Museum of Natural History.[10]

The Dutch island administration, realizing the limited number of individuals in the wild, soon outlawed sport hunting and heavily limited the number of individuals taken for scientific study. Collecting expeditions ground to a halt with the occurrence of World War II, not resuming until the 1950s and 1960s, when studies examined the Komodo dragon's feeding behavior, reproduction, and body temperature. At around this time, an expedition was planned in which a long-term study of the Komodo dragon would be undertaken. This task was given to the Auffenberg family, who stayed on Komodo Island for 11 months in 1969. During their stay, Walter Auffenberg and his assistant Putra Sastrawan captured and tagged more than 50 Komodo dragons.[11]

Research from the Auffenberg expedition proved enormously influential in raising Komodo dragons in captivity.[12] Research after that of the Auffenberg family has shed more light on the nature of the Komodo dragon, with biologists such as Claudio Ciofi continuing to study the creatures.[13]

Etymology

The Komodo dragon, as depicted on the 50 rupiah coin, issued by Indonesia

The Komodo dragon is also sometimes known as the Komodo monitor or the Komodo Island monitor in scientific literature,[14] although these name are uncommon. To the natives of Komodo Island, it is referred to as ora, buaya darat ('land crocodile'), or biawak raksasa ('giant monitor').[15][5]

Evolutionary history

The evolutionary development of the Komodo dragon started with the genus Varanus, which originated in Asia about 40 million years ago and migrated to Australia, where it evolved into giant forms (the largest of all being the recently extinct Varanus priscus, or "Megalania"), helped by the absence of competing placental carnivorans. Around 15 million years ago, a collision between the continental landmasses of Australia and Southeast Asia allowed these larger varanids to move back into what is now the Indonesian archipelago, extending their range as far east as the island of Timor.

The Komodo dragon is believed to have differentiated from its Australian ancestors about 4 million years ago. However, fossil evidence from Queensland suggests the Komodo dragon actually evolved in Australia, before spreading to Indonesia.[1][16] The oldest records of the Komodo dragon on Flores date to over 1.3 million years ago.[17]

Dramatic lowering of sea level during the last glacial period uncovered extensive stretches of continental shelf that the Komodo dragon colonised, becoming isolated in their present island range as sea levels rose afterwards.[1][5] Fossils of extinct Pliocene species of similar size to the modern Komodo dragon, such as Varanus sivalensis, have been found in Eurasia as well, indicating that they fared well even in environments containing competition, such as mammalian carnivores, until the climate change and extinction events that marked the beginning of the Pleistocene.[1]

Genetic analysis of mitochondrial DNA shows the Komodo dragon to be the closest relative (sister taxon) of the lace monitor (V. varius), with their common ancestor diverging from a lineage that gave rise to the crocodile monitor (Varanus salvadorii) of New Guinea.[18][19][20] A 2021 study showed that during the Miocene, Komodo dragons had hybridized with the ancestors of the Australian sand monitor (V. gouldii), thus providing further evidence that the Komodo dragon had once inhabited Australia.[21][22][23] Genetic analysis indicates that the population from northern Flores is genetically distinct from other populations of the species.[2]With the Komodo's similarities to extinct species of large lizards, their teeth has been used to date and predict the size of theropod dinosaurs. [24]

Description

Specimen in profile

In the wild, adult Komodo dragons usually weigh around 70 kg (150 lb), although captive specimens often weigh more.[25] According to Guinness World Records, an average adult male will weigh 79 to 91 kg (174 to 201 lb) and measure 2.59 m (8.5 ft), while an average female will weigh 68 to 73 kg (150 to 161 lb) and measure 2.29 m (7.5 ft).[26] The largest verified specimen in captive was 3.13 m (10.3 ft) long and weighed 166 kg (366 lb), including its undigested food.[5] The largest wild specimen had a length 3.04 m (10.0 ft), a snout-vent length (SVL) 1.54 m (5 ft 1 in) and a mass of 81.5 kg (180 lb) excluding stomach contents.[27][28] The heaviest reached a mass in 87.4 kg (193 lb).[27] The study noted that weights greater than 100 kg (220 lb) were possible but only after the animal had consumed a large meal.[27][28]

Closeup of the skin

The Komodo dragon has a tail as long as its body, as well as about 60 frequently replaced, serrated teeth that can measure up to 2.5 cm (1 in) in length. Its saliva is frequently blood-tinged because its teeth are almost completely covered by gingival tissue that is naturally lacerated during feeding.[29] It also has a long, yellow, deeply forked tongue.[5] Komodo dragon skin is reinforced by armoured scales, which contain tiny bones called osteoderms that function as a sort of natural chain-mail.[30][31] The only areas lacking osteoderms on the head of the adult Komodo dragon are around the eyes, nostrils, mouth margins, and pineal eye, a light-sensing organ on the top of the head. Where lizards typically have one or two varying patterns or shapes of osteoderms, komodos have four: rosette, platy, dendritic, and vermiform.[32] This rugged hide makes Komodo dragon skin a poor source of leather. Additionally, these osteoderms become more extensive and variable in shape as the Komodo dragon ages, ossifying more extensively as the lizard grows. These osteoderms are absent in hatchlings and juveniles, indicating that the natural armor develops as a product of age and competition between adults for protection in intraspecific combat over food and mates.[33]

Senses

Komodo dragon using its tongue to sample the air

As with other varanids, Komodo dragons have only a single ear bone, the stapes, for transferring vibrations from the tympanic membrane to the cochlea. This arrangement means they are likely restricted to sounds in the 400 to 2,000 hertz range, compared to humans who hear between 20 and 20,000 hertz.[5][34] They were formerly thought to be deaf when a study reported no agitation in wild Komodo dragons in response to whispers, raised voices, or shouts. This was disputed when London Zoological Garden employee Joan Procter trained a captive specimen to come out to feed at the sound of her voice, even when she could not be seen.[35]

The Komodo dragon can see objects as far away as 300 m (980 ft), but because its retinas only contain cones, it is thought to have poor night vision. It can distinguish colours, but has poor visual discrimination of stationary objects.[36]

As with many other reptiles, the Komodo dragon primarily relies on its tongue to detect, taste, and smell stimuli, with the vomeronasal sense using the Jacobson's organ, rather than using the nostrils.[37] With the help of a favorable wind and its habit of swinging its head from side to side as it walks, a Komodo dragon may be able to detect carrion from 4–9.5 km (2.5–5.9 mi) away.[36] It only has a few taste buds in the back of its throat.[37] Its scales, some of which are reinforced with bone, have sensory plaques connected to nerves to facilitate its sense of touch. The scales around the ears, lips, chin, and soles of the feet may have three or more sensory plaques.[29]

Behaviour and ecology

Male komodo dragons fighting

The Komodo dragon prefers hot and dry places and typically lives in dry, open grassland, savanna, and tropical forest at low elevations. As an ectotherm, it is most active in the day, although it exhibits some nocturnal activity. Komodo dragons are solitary, coming together only to breed and eat. They are capable of running rapidly in brief sprints up to 20 km/h (12 mph), diving up to 4.5 m (15 ft), and climbing trees proficiently when young through use of their strong claws.[25] To catch out-of-reach prey, the Komodo dragon may stand on its hind legs and use its tail as a support.[35] As it matures, its claws are used primarily as weapons, as its great size makes climbing impractical.[29]

For shelter, the Komodo dragon digs holes that can measure from 1 to 3 m (3.3 to 9.8 ft) wide with its powerful forelimbs and claws.[38] Because of its large size and habit of sleeping in these burrows, it is able to conserve body heat throughout the night and minimise its basking period the morning after.[39] The Komodo dragon hunts in the afternoon, but stays in the shade during the hottest part of the day.[9] These special resting places, usually located on ridges with cool sea breezes, are marked with droppings and are cleared of vegetation. They serve as strategic locations from which to ambush deer.[40]

Diet

Komodo dragon on Rinca feeding on a water buffalo corpse

Komodo dragons are apex predators.[41] They are carnivores; although they have been considered as eating mostly carrion,[42] they will frequently ambush live prey with a stealthy approach. When suitable prey arrives near a dragon's ambush site, it will suddenly charge at the animal at high speeds and go for the underside or the throat.[29]

Komodo dragons do not deliberately allow the prey to escape with fatal injuries but try to kill prey outright using a combination of lacerating damage and blood loss. They have been recorded as killing wild pigs within seconds,[43] and observations of Komodo dragons tracking prey for long distances are likely misinterpreted cases of prey escaping an attack before succumbing to infection. Most prey attacked by a Komodo dragon reputedly suffer from said sepsis and will later be eaten by the same or other lizards.[44]

Komodo dragons eat by tearing large chunks of flesh and swallowing them whole while holding the carcass down with their forelegs. For smaller prey up to the size of a goat, their loosely articulated jaws, flexible skulls, and expandable stomachs allow them to swallow prey whole. The undigested vegetable contents of a prey animal's stomach and intestines are typically avoided.[40] Copious amounts of red saliva the Komodo dragons produce help to lubricate the food, but swallowing is still a long process (15–20 minutes to swallow a goat). A Komodo dragon may attempt to speed up the process by ramming the carcass against a tree to force it down its throat, sometimes ramming so forcefully that the tree is knocked down.[40] A small tube under the tongue that connects to the lungs allows it to breathe while swallowing.[29]

After eating up to 80% of its body weight in one meal,[41] it drags itself to a sunny location to speed digestion, as the food could rot and poison the dragon if left undigested in its stomach for too long. Because of their slow metabolism, large dragons can survive on as few as 12 meals a year.[29] After digestion, the Komodo dragon regurgitates a mass of horns, hair, and teeth known as the gastric pellet, which is covered in malodorous mucus. After regurgitating the gastric pellet, it rubs its face in the dirt or on bushes to get rid of the mucus.[29]

Komodo excrement has a dark portion, which is stool, and a whitish portion, which is urate, the nitrogenous end-product of their digestion process

The eating habits of Komodo dragons follow a hierarchy, with the larger animals generally eating before the smaller ones. The largest male typically asserts his dominance and the smaller males show their submission by use of body language and rumbling hisses. Dragons of equal size may resort to "wrestling". Losers usually retreat, though they have been known to be killed and eaten by victors.[45][46]

The Komodo dragon's diet is wide-ranging, and includes invertebrates, other reptiles (including smaller Komodo dragons), birds, bird eggs, small mammals, monkeys, wild boar, goats, pigs,[47] deer, horses, and water buffalo.[48] Young Komodos will eat insects, eggs, geckos, and small mammals, while adults prefer to hunt large mammals.[42] Occasionally, they attack and bite humans. Sometimes they consume human corpses, digging up bodies from shallow graves.[35] This habit of raiding graves caused the villagers of Komodo to move their graves from sandy to clay ground, and pile rocks on top of them, to deter the lizards.[40] The Komodo dragon may have evolved to feed on the extinct dwarf species of Stegodon (a member of Proboscidea related to elephants) that once lived on Flores, according to evolutionary biologist Jared Diamond.[49]

The Komodo dragon drinks by sucking water into its mouth via buccal pumping (a process also used for respiration), lifting its head, and letting the water run down its throat.[43]

Saliva

Although previous studies proposed that Komodo dragon saliva contains a variety of highly septic bacteria that would help to bring down prey,[45][50] research in 2013 suggested that the bacteria in the mouths of Komodo dragons are ordinary and similar to those found in other carnivores. Komodo dragons have good mouth hygiene. To quote Bryan Fry: "After they are done feeding, they will spend 10 to 15 minutes lip-licking and rubbing their head in the leaves to clean their mouth ... Unlike people have been led to believe, they do not have chunks of rotting flesh from their meals on their teeth, cultivating bacteria." Nor do Komodo dragons wait for prey to die and track it at a distance, as vipers do; observations of them hunting deer, boar and in some cases buffalo reveal that they kill prey in less than half an hour.[51]

The observation of prey dying of sepsis would then be explained by the natural instinct of water buffalos, who are not native to the islands where the Komodo dragon lives, to run into water after escaping an attack. The warm, faeces-filled water would then cause the infections. The study used samples from 16 captive dragons (10 adults and six neonates) from three US zoos.[51]

Antibacterial immune factor

Researchers have isolated a powerful antibacterial peptide from the blood plasma of Komodo dragons, VK25. Based on their analysis of this peptide, they have synthesized a short peptide dubbed DRGN-1 and tested it against multidrug-resistant (MDR) pathogens. Preliminary results of these tests show that DRGN-1 is effective in killing drug-resistant bacterial strains and even some fungi. It has the added observed benefit of significantly promoting wound healing in both uninfected and mixed biofilm infected wounds.[52]

Venom

Komodo dragon stalking a Timor deer

In late 2005, researchers at the University of Melbourne speculated the perentie (Varanus giganteus), other species of monitors, and agamids may be somewhat venomous. The team believes the immediate effects of bites from these lizards were caused by mild envenomation. Bites on human digits by a lace monitor (V. varius), a Komodo dragon, and a spotted tree monitor (V. scalaris) all produced similar effects: rapid swelling, localised disruption of blood clotting, and shooting pain up to the elbow, with some symptoms lasting for several hours.[53]

In 2009, the same researchers published further evidence demonstrating Komodo dragons possess a venomous bite. MRI scans of a preserved skull showed the presence of two glands in the lower jaw. The researchers extracted one of these glands from the head of a terminally ill dragon in the Singapore Zoological Gardens, and found it secreted several different toxic proteins. The known functions of these proteins include inhibition of blood clotting, lowering of blood pressure, muscle paralysis, and the induction of hypothermia, leading to shock and loss of consciousness in envenomated prey.[54][55] As a result of the discovery, the previous theory that bacteria were responsible for the deaths of Komodo victims was disputed.[56]

Other scientists have stated that this allegation of venom glands "has had the effect of underestimating the variety of complex roles played by oral secretions in the biology of reptiles, produced a very narrow view of oral secretions and resulted in misinterpretation of reptilian evolution." According to these scientists "reptilian oral secretions contribute to many biological roles other than to quickly dispatch prey." These researchers concluded that, "Calling all in this clade venomous implies an overall potential danger that does not exist, misleads in the assessment of medical risks, and confuses the biological assessment of squamate biochemical systems."[57] Evolutionary biologist Schwenk says that even if the lizards have venom-like proteins in their mouths they may be using them for a different function, and he doubts venom is necessary to explain the effect of a Komodo dragon bite, arguing that shock and blood loss are the primary factors.[58][59]

Reproduction

Komodo dragons mating

Mating occurs between May and August, with the eggs laid in September.[5][60] During this period, males fight over females and territory by grappling with one another upon their hind legs, with the loser eventually being pinned to the ground. These males may vomit or defecate when preparing for the fight.[35] The winner of the fight will then flick his long tongue at the female to gain information about her receptivity.[41] Females are antagonistic and resist with their claws and teeth during the early phases of courtship. Therefore, the male must fully restrain the female during coitus to avoid being hurt. Other courtship displays include males rubbing their chins on the female, hard scratches to the back, and licking.[61] Copulation occurs when the male inserts one of his hemipenes into the female's cloaca.[36] Komodo dragons may be monogamous and form "pair bonds", a rare behavior for lizards.[35]

Female Komodos lay their eggs from August to September and may use several types of locality; in one study, 60% laid their eggs in the nests of orange-footed scrubfowl (a moundbuilder or megapode), 20% on ground level and 20% in hilly areas.[62] The females make many camouflage nests/holes to prevent other dragons from eating the eggs.[63] Clutches contain an average of 20 eggs, which have an incubation period of 7–8 months.[35] Hatching is an exhausting effort for the neonates, which break out of their eggshells with an egg tooth that falls off before long. After cutting themselves out, the hatchlings may lie in their eggshells for hours before starting to dig out of the nest. They are born quite defenseless and are vulnerable to predation.[45] Sixteen youngsters from a single nest were on average 46.5 cm long and weighed 105.1 grams.[62]

Young Komodo dragons spend much of their first few years in trees, where they are relatively safe from predators, including cannibalistic adults, as juvenile dragons make up 10% of their diets.[35] The habit of cannibalism may be advantageous in sustaining the large size of adults, as medium-sized prey on the islands is rare.[64] When the young approach a kill, they roll around in faecal matter and rest in the intestines of eviscerated animals to deter these hungry adults.[35] Komodo dragons take approximately 8 to 9 years to mature, and may live for up to 30 years.[60]

Parthenogenesis

Parthenogenetic baby Komodo dragon, Chester Zoo, England

A Komodo dragon at London Zoo named Sungai laid a clutch of eggs in late 2005 after being separated from male company for more than two years. Scientists initially assumed she had been able to store sperm from her earlier encounter with a male, an adaptation known as superfecundation.[65] On 20 December 2006, it was reported that Flora, a captive Komodo dragon living in the Chester Zoo in England, was the second known Komodo dragon to have laid unfertilised eggs: she laid 11 eggs, and seven of them hatched, all of them male.[66] Scientists at Liverpool University in England performed genetic tests on three eggs that collapsed after being moved to an incubator, and verified Flora had never been in physical contact with a male dragon. After Flora's eggs' condition had been discovered, testing showed Sungai's eggs were also produced without outside fertilization.[67] On 31 January 2008, the Sedgwick County Zoo in Wichita, Kansas, became the first zoo in the Americas to document parthenogenesis in Komodo dragons. The zoo has two adult female Komodo dragons, one of which laid about 17 eggs on 19–20 May 2007. Only two eggs were incubated and hatched due to space issues; the first hatched on 31 January 2008, while the second hatched on 1 February. Both hatchlings were males.[68][69]

Komodo dragons have the ZW chromosomal sex-determination system, as opposed to the mammalian XY system. Male progeny prove Flora's unfertilized eggs were haploid (n) and doubled their chromosomes later to become diploid (2n) (by being fertilized by a polar body, or by chromosome duplication without cell division), rather than by her laying diploid eggs by one of the meiosis reduction-divisions in her ovaries failing. When a female Komodo dragon (with ZW sex chromosomes) reproduces in this manner, she provides her progeny with only one chromosome from each of her pairs of chromosomes, including only one of her two sex chromosomes. This single set of chromosomes is duplicated in the egg, which develops parthenogenetically. Eggs receiving a Z chromosome become ZZ (male); those receiving a W chromosome become WW and fail to develop,[70][71] meaning that only males are produced by parthenogenesis in this species.

It has been hypothesised that this reproductive adaptation allows a single female to enter an isolated ecological niche (such as an island) and by parthenogenesis produce male offspring, thereby establishing a sexually reproducing population (via reproduction with her offspring that can result in both male and female young).[70] Despite the advantages of such an adaptation, zoos are cautioned that parthenogenesis may be detrimental to genetic diversity.[72]

Encounters with humans

Humans handling a komodo dragon

Attacks on humans are rare, but Komodo dragons have been responsible for several human fatalities, in both the wild and in captivity. According to data from Komodo National Park spanning a 38-year period between 1974 and 2012, there were 24 reported attacks on humans, five of them fatal. Most of the victims were local villagers living around the national park.[73]

Conservation

Komodo dragons on Rinca

The Komodo dragon is classified by the IUCN as Endangered and is listed on the IUCN Red List.[2] The species' sensitivity to natural and man-made threats has long been recognized by conservationists, zoological societies, and the Indonesian government. Komodo National Park was founded in 1980 to protect Komodo dragon populations on islands including Komodo, Rinca, and Padar.[74] Later, the Wae Wuul and Wolo Tado Reserves were opened on Flores to aid Komodo dragon conservation.[13]

Komodo dragons generally avoid encounters with humans. Juveniles are very shy and will flee quickly into a hideout if a human comes closer than about 100 metres (330 ft). Older animals will also retreat from humans from a shorter distance away. If cornered, they may react aggressively by gaping their mouth, hissing, and swinging their tail. If they are disturbed further, they may attack and bite. Although there are anecdotes of unprovoked Komodo dragons attacking or preying on humans, most of these reports are either not reputable or have subsequently been interpreted as defensive bites. Only very few cases are truly the result of unprovoked attacks by atypical individuals who lost their fear of humans.[45]

Volcanic activity, earthquakes, loss of habitat, fire,[29][13] tourism, loss of prey due to poaching, and illegal poaching of the dragons themselves have all contributed to the vulnerable status of the Komodo dragon. A major future threat to the species is climate change via both aridification and sea level rise, which can affect the low-lying habitats and valleys that the Komodo dragon depends on, as Komodo dragons do not range into the higher-altitude regions of the islands they inhabit. Based on projections, climate change will lead to a decline in suitable habitat of 8.4%, 30.2%, or 71% by 2050 depending on the climate change scenario. Without effective conservation actions, populations on Flores are extirpated in all scenarios, while in the more extreme scenarios, only the populations on Komodo and Rinca persist in highly reduced numbers. Rapid climate change mitigation is crucial for conserving the species in the wild.[2][75] Other scientists have disputed the conclusions about the effects of climate change on Komodo dragon populations.[76]

Under Appendix I of CITES (the Convention on International Trade in Endangered Species), commercial international trade of Komodo dragon skins or specimens is prohibited.[77][78] Despite this, there are occasional reports of illegal attempts to trade in live Komodo dragons. The most recent attempt was in March 2019, when Indonesian police in the East Java city of Surabaya reported that a criminal network had been caught trying to smuggle 41 young Komodo dragons out of Indonesia. The plan was said to include shipping the animals to several other countries in Southeast Asia through Singapore. It was hoped that the animals could be sold for up to 500 million rupiah (around US$35,000) each.[79] It was believed that the Komodo dragons had been smuggled out of East Nusa Tenggara province through the port at Ende in central Flores.[80]

In 2013, the total population of Komodo dragons in the wild was assessed as 3,222 individuals, declining to 3,092 in 2014 and 3,014 in 2015. Populations remained relatively stable on the bigger islands (Komodo and Rinca), but decreased on smaller islands, such as Nusa Kode and Gili Motang, likely due to diminishing prey availability.[81] On Padar, a former population of Komodo dragons has recently become extinct, of which the last individuals were seen in 1975.[82] It is widely assumed that the Komodo dragon died out on Padar following a major decline of populations of large ungulate prey, for which poaching was most likely responsible.[83]

In captivity

Komodo dragon in San Diego Zoo (video clip)

Komodo dragons have long been sought-after zoo attractions, where their size and reputation make them popular exhibits. They are, however, rare in zoos because they are susceptible to infection and parasitic disease if captured from the wild, and do not readily reproduce in captivity.[15] The first Komodo dragons were displayed at London Zoo in 1927. A Komodo dragon was exhibited in 1934 in the United States at the National Zoo in Washington, D.C., but it lived for only two years. More attempts to exhibit Komodo dragons were made, but the lifespan of the animals proved very short, averaging five years in the National Zoological Park. Studies were done by Walter Auffenberg, which were documented in his book The Behavioral Ecology of the Komodo Monitor, eventually allowed for more successful management and breeding of the dragons in captivity.[12] As of May 2009, there were 35 North American, 13 European, one Singaporean, two African, and two Australian institutions which housed captive Komodo dragons.[84]

A variety of behaviors have been observed from captive specimens. Most individuals become relatively tame within a short time,[85][86] and are capable of recognising individual humans and discriminating between familiar and unfamiliar keepers.[87] Komodo dragons have also been observed to engage in play with a variety of objects, including shovels, cans, plastic rings, and shoes. This behavior does not seem to be "food-motivated predatory behavior".[41][5][88]

Even seemingly docile dragons may become unpredictably aggressive, especially when the animal's territory is invaded by someone unfamiliar. In June 2001, a Komodo dragon seriously injured Phil Bronstein, the then-husband of actress Sharon Stone, when he entered its enclosure at the Los Angeles Zoo after being invited in by its keeper. Bronstein was bitten on his bare foot, as the keeper had told him to take off his white shoes and socks, which the keeper stated could potentially excite the Komodo dragon as they were the same colour as the white rats the zoo fed the dragon.[89][90] Although he survived, Bronstein needed to have several tendons in his foot reattached surgically.[91]

See also

References

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Komodo dragon: Brief Summary

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The Komodo dragon (Varanus komodoensis), also known as the Komodo monitor, is a member of the monitor lizard family Varanidae that is endemic to the Indonesian islands of Komodo, Rinca, Flores, and Gili Motang. It is the largest extant species of lizard, growing to a maximum length of 3 m (9.8 ft), and weighing up to 70 kg (150 lb).

As a result of their size, Komodo dragons are apex predators, and dominate the ecosystems in which they live. Komodo dragons hunt and ambush prey including invertebrates, birds, and mammals. Komodo dragons' group behavior in hunting is exceptional in the reptile world. The diet of Komodo dragons mainly consists of Javan rusa (Rusa timorensis), though they also eat considerable amounts of carrion. Komodo dragons also occasionally attack humans.

Mating begins between May and August, and the eggs are laid in September; as many as 20 eggs are deposited at a time in an abandoned megapode nest or in a self-dug nesting hole. The eggs are incubated for seven to eight months, hatching in April, when insects are most plentiful. Young Komodo dragons are vulnerable and dwell in trees to avoid predators, such as cannibalistic adults. They take 8 to 9 years to mature and are estimated to live up to 30 years.

Komodo dragons were first recorded by Western scientists in 1910. Their large size and fearsome reputation make them popular zoo exhibits. In the wild, their range has contracted due to human activities, and is likely to contract further from the effects of climate change; due to this, they are listed as Endangered by the IUCN Red List. They are protected under Indonesian law, and Komodo National Park was founded in 1980 to aid protection efforts.

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