KOMODO DRAGON: CHARACTERISTICS, SPEED, HABITAT, BEHAVIOR - BIOLOGY - 2025

The Komodo dragon (Varanus komodoensis) is a reptile that belongs to the Varanidae family. This lizard is the largest of all those currently living on Earth. Its body can measure up to three meters and it has a muscular and strong tail, almost the same size as its body.

The speed of the Komodo dragon can reach 20 kilometers per hour, being one of the fastest reptiles. When running, they lift their tail off the ground and keep their body rigid. Also, they are skilled swimmers.

Komodo dragon. Source: Mark Dumont

The limbs are robust and the head features a rounded snout with sharp teeth. It has two venom glands, located in the lower jaw. As for the skull, it is flexible and, although it is not adapted to provide a strong bite, it does withstand high tensile loads.

Thus, when the Komodo dragon bites the prey, it does so deeply and tears the skin, making it easier for the venom to enter the animal's bloodstream. In this way, in a short time, it dies from the anticoagulant action of the toxic substance and from the abundant loss of blood.

Regarding its distribution, it lives in Indonesia, on the Rinca, Flores, Gili Motang, Komodo and Gili Dasami islands. In these regions, it lives in warm areas such as dry deciduous forests, savannas, and open grasslands.

Evolution

The evolutionary development of Varanus komodoensis begins with the genus Varanus. This had its origin in Asia, around 40 million years ago. It later migrated to Australia, evolving into larger forms, such as the recently extinct Varanus megalania.

15 million years ago, members of the genus Varanus arrived in the Indonesian archipelago. This happened after the landmasses of Southeast Asia and Australia collided.

Some experts say that, at that time, the largest varánids were those that returned to Indonesia. Four years later, the Komodo dragon differed from these Australian ancestors. However, fossils recently found in Queensland suggest that Varanus komodoensis evolved in Australia, before reaching Indonesia.

In the last ice age, the dramatic lowering of the sea level uncovered vast areas of the continental shelf, which were colonized by the Komodo dragon. In this way, the reptile was isolated in its current range, as sea levels progressively increased.

characteristics

Size

The Komodo dragon is one of the largest lizards. Also, males are larger than females. Thus, an adult male weighs between 79 and 91 kilograms and measures an average of 2.59 meters.

In relation to the female, it has a body mass of 68 to 74 kilograms, with a body length of approximately 2.29 meters. However, researchers have reported species of up to 3.13 meters, weighing 166 kilograms.

Mouth

In 2009, researchers showed that the Komodo dragon has a poisonous sting. This reptile has two glands in the lower jaw, which secrete various toxic proteins.

They work by inhibiting blood clotting and lowering blood pressure. This causes muscle paralysis and hypothermia, leading the body into a state of shock. This discovery refutes the theory that bacteria are responsible for the death of Varanus komodoensis prey.

However, some evolutionary biologists argue that this reptile can use the venom for other biological functions than to kill the prey. This is based on the fact that blood loss and shock are only primary factors, a product of the action of the toxic substance. In the following video you can see the morphology of this species:

Taxonomy

-Animal Kingdom.

-Subreino: Bilateria.

-Filum: Cordate.

-Subfilum: Vertebrate.

-Infrafilum: Gnathostomata.

-Superclass: Tetrapoda.

-Class: Reptilia.

-Order: Squamata.

-Suborder: Autarchoglossa.

-Family: Varanidae.

-Gender: Varanus.

-Species: Varanus komodoensis.

Habitat and distribution

Distribution

The Komodo dragon is distributed on five Indonesian islands. One of these is the island of Flores, and the remaining four, Rinca, Komodo, Gili Dasami and Gili Motang, are located within the Komodo National Park.

Today, on the island of Flores, the Varanus komodoensis is threatened with extinction. Its population density is considerably much lower than in Komodo and the neighboring small islands. Studies indicate that communities are probably declining north of Flores.

Thus, its distribution in Flores is restricted to the western Manggarai region, specifically in the area that includes Labuan Bajo. Also, it extends to the southeast and south, towards Nanga Lili and on the Sanga Benga mountain.

In the late 1970s, V. komodoensis became extinct from the small island of Padar, located between Rinca and Komodo. This was due to the reduction of the populations of deer, their main food.

On the other hand, this species has been sighted on the island of Sumbawa, specifically on the southern coast of the island. However, it is currently unknown if it really is a stable population.

Habitat

These island territories have a volcanic origin. They are mountainous and rugged, being covered with savanna grasslands and forests. In these there are two seasons, a moderate winter, from January to March, and a long summer.

Varanus komodoensis inhabits from tropical dry forests to savannas or deciduous monsoon forests. One of the main characteristics of these regions is the high daytime temperature, which occurs during the summer. In general, the average is 35 ° C, with a degree of humidity close to 70%.

The Komodo dragon lives in rocky valleys, between 500 and 700 meters above sea level. This reptile prefers dry and warm regions, such as open grasslands and lowland areas, with an abundance of shrubs and tall grasses. However, it can be found in dry riverbeds and beaches.

Some species dig shallow burrows, although you can also use one that has been freed by another lizard. The animal goes to this space with the intention of resting and keeping warm at night. During the day, the shelter is kept cool, so the animal uses it to reduce the heat of the day.

State of conservation

Varanus komodoensis populations are decreasing as they are affected by various factors, both natural and those associated with human actions. Communities remain relatively stable on the larger islands, such as Rinca and Komodo.

However, on the smaller islands, such as Gili Motang and Nusa Kode, they are gradually declining. In Padar, until 1975 there was evidence of the presence of this species, so this ancient population in that island territory is considered extinct. This situation has caused the IUCN to classify V. komodoensis as a species vulnerable to extinction.

Among the threats are the eruption of volcanoes, forest fires and earthquakes. In addition, it is affected by tourist activities in the area, the loss of the prey that make up its diet and illegal hunting.

Actions

The Komodo dragon is listed in Appendix I of CITES. In this group are those species that are in danger of becoming extinct, so their international trade is not allowed. Importation is only authorized when it is not for commercial purposes, such as for scientific research.

Due to the rapid decline in populations, in 1980 the Komodo National Park was created. The fundamental purpose of this ecological reserve is the creation of a protection area, where actions are promoted that allow to preserve this species in its natural environment.

Subsequently, the Wolo Tado and Wae Wuul Reserves, in Flores, were opened. In these, the reptile is protected from the threats that affect it.

Feeding

Varanus komodoensis is a carnivore. Its diet varies according to the stage of development in which it is. Thus, the young eat almost exclusively insects, while the young eat beetles, grasshoppers, birds, rodents, lizards, eggs and eventually some small mammals.

The adult has a much more extensive diet, although they basically eat carrion. However, it can attack goats, deer, pigs, horses, wild boars, water buffalo, snakes, and even smaller Komodo dragons.

- Hunting method

To capture his prey, he ambushes it, stealthily waiting for it to approach where he is. When that happens, it pounces on the animal, biting it by the throat or bottom. This reptile prevents the injured animal from escaping, even if it has fatal injuries.

When attacking, it attempts to kill prey quickly, combining deep wounds with loss of blood. In the case of pigs or deer, they can knock them down with their strong and powerful tail.

In relation to the search for carrion, a product of the organic remains left abandoned by other predators, it usually uses the Jacobson's organ. This specialized structure takes the olfactory stimuli that the tongue has picked up and transmits them to the brain.

By interpreting them, the reptile obtains the information about the location of the carrion. Thus, you can locate a dying or dead animal, which is up to 9.5 kilometers away.

At mealtime, the larger adults eat first, while the little ones wait their turn. Between these a fight for the hierarchy can occur, where the losers generally retreat, although they could be killed and ingested by the victors.

- Intake

The Komodo dragon holds the corpse with its forelimbs. Then he rips large chunks of meat with his teeth, swallowing them whole. In the case that the prey is small, eat it whole.

This can be done due to some morphological peculiarities of this species. These include its articulated jaw, expandable stomach, and flexible skull.

Digestive process

To lubricate the passage of the animal through the esophagus, the salivary glands produce a large amount of saliva. However, the swallowing process is long, and can take between 15 and 20 minutes. To speed it up, the Komodo dragon often hits its body against a tree trunk, forcing food down the throat.

While the prey is ingested, the reptile breathes thanks to a structure, similar to a tube, which is located below the league and connects with the airways.

When the food reaches the stomach, the Varanus komodoensis goes to a sunny place, to speed up digestion. Once the food has been processed, it regurgitates a mass covered with mucus. This contains hair, teeth and some bone structures, such as horns.

Regarding the intake of water, it does so by sucking it through the mouth, by pumping the mouth. Then lift your head and let the water run down your throat.

Saliva

In some studies carried out, Komodo dragon saliva was given septic properties, associated with the diversity of bacteria it contains. However, recent research indicates that the microorganisms present in saliva are very similar to those of other carnivores.

On the other hand, this species meticulously cleans its mouth after eating, thus preventing the proliferation of bacteria. During oral hygiene, the reptile licks its lips for approximately 10 to 15 minutes. Also, he usually cleans his mouth, rubbing it with leaves.

- Ecology of predation

Recently, various investigative works have been carried out, related to the mechanisms used by Varanus komodoensis to kill its prey. Experts say that this species has a sophisticated set of adaptations that work in combination.

In this sense, the skull is poorly adapted to generate high bite forces. However, it can withstand high tensile loads. Although its bite is not powerful, this animal can cause lethal wounds, which cause death by exsanguination.

Lesions are created when the reptile bites and simultaneously pulls on its prey, using its postcranial muscles. In this way, it complements the weak action of the adductors of the jaw.

Poison action

Likewise, specialists point out that the death of the animal is not due to the action of toxic bacteria. Instead, they claim that the effect of deep wounds is potentiated through poison, which has anticoagulant and organic shock-inducing effects.

Poisoning plays an important role in the death of the prey. However, this aspect has not been studied in depth, probably due to the lack of specialized teeth that supply the venom. In the case of the Komodo dragon, the two wounds facilitate the entry of the toxic substance into the body of the prey.

Reproduction

In general, this species reaches sexual maturity between 5 and 7 years. However, the female could reproduce after 9 years and the male after 10 years.

When the female is able to mate, her feces have a particular aroma, which is detected by the males. These fight each other to join with the females. During the fight, they usually assume a vertical position, thus trying to throw the opponent to the ground.

The victor rubs his chin on the female's head, scratches her back and licks her body. Later he grabs it with his legs and introduces one of his hemipenis into her cloaca. In the following video you can see how two specimens mate:

The breeding period occurs annually between July and August. The female digs a nest in the ground, where she lays an average of 20 eggs. Then she covers them with leaves and soil and lies on these, incubating them for seven to eight months.

The hatchlings are about 37 centimeters in length. Due to their high mortality rate, they soon climb trees, seeking protection from predators.

Parthenogenesis

In this type of sexual reproduction, the female reproductive cells, the ovules, develop without having been fertilized by sperm. In the case of the Komodo dragon, all the offspring are male.

Experts explain this based on the ZW sex determination system, with males being ZZ and females being ZW. The female provides a haploid number of chromosomes, which can be Z or W. This is replicated, so the Z chromosome becomes male (ZZ) and the embryo that receives the W chromosome will be WW and does not develop.

Behavior

Varanus komodoensis has diurnal habits, although it frequently exhibits nocturnal activities. It is a solitary animal, which forms a couple only when it reproduces. Also, it can be grouped around a dead animal, where, in a hierarchical way, they take turns eating the carrion.

Thus, the largest males are the first to eat, followed by the females and the smallest males. Finally the young do, descending from the trees when the adults move away.

Komodo dragons roam their home ranges all day long, which can span up to 1.9 km2. It is not a territorial reptile, so the areas can overlap.

If the animal feels cornered, it tends to react aggressively. Thus, it opens its mouth, whistles, arches its back and whips its tail.

Despite its large size, it can run short-distance races and dive, up to 4.5 meters. Young people use their claws to climb trees, but when they are adults their weight prevents them from climbing

When it needs to catch prey, it can stand on its two hind legs, using its long tail for support.

References

1. Wikipedia (2019). Komodo dragon. Recovered from en.wikipedia.org.
2. Lawwell, L. (2006). Varanus komodoensis. Animal Diversity Web. Recovered from animaldiversity.org.
3. World Conservation Monitoring Center (1996). Varanus komodoensis. The IUCN Red List of Threatened Species 1996. Recovered from iucnredlist.org.
4. Alina Bradford (2014). Komodo Dragon Facts. Recovered from livescience.com.
5. ITIS (2019). Varanus komodoensis. Recovered from itis.gov.
6. Teresa Dang (2019). Komodo Dragon: Varanus komodoensis. Recovered from tolweb.org.
7. Bryan G. Fry, Stephen Wroe, Wouter Teeuwisse, Matthias JP van Osch, Karen Moreno, Janette Ingle, Colin McHenry, Toni Ferrara, Phillip Clausen, Holger Scheib, Kelly L. Winter, Laura Greisman, Kim Roelants, Louise van der Weerd, Christofer J. Clemente, Eleni Giannakis, Wayne C. Hodgson, Sonja Luz, Paolo Martelli, Karthiyani Krishnasamy, Elazar Kochva, Hang Fai Kwok, Denis Scanlon, John Karas, Diane M. Citron, Ellie JC Goldstein, Judith E. Mcnaughtan, Janette A. Norman. (2009). A central role for venom in predation by Varanus komodoensis (Komodo Dragon) and the extinct giant Varanus (Megalania) priscus. Recovered from pnas.org.
8. Karen Moreno, Stephen Wroe, Philip Clausen, Colin McHenry, Domenic C D'Amore, Emily J Rayfield, Eleanor Cunningham (2008). Cranial performance in the Komodo dragon (Varanus komodoensis) as revealed by high-resolution 3-D finite element analysis. Recovered from ncbi.nlm.nih.gov.