Komodo dragons and their behaviour - Essay Example

Komodo Dragons and their Behavior Introduction Management and conservation of the natural environment is hailed as one of the most important approaches to ecology. Many public campaigns have been developed to educate people on the need for managing natural environments. Similarly, scientific research continues to be conducted to identify various ways of protecting natural habitats. It is important that people understand how different animals coexist in their natural habits, which can help in the development of effective management and conservation systems. Nevertheless, the process of applying ethological methods and principles for studying animal behavior is still new (Ariefiandy et al. 69). So far, many stimulating discussions and controversies continue to emerge on this important subject. In this regard, this paper presents an examination of the way reptiles live and behave in their natural habitat. 1. Reptiles Reptiles, belong to the class referred to as Reptilia, can be described as the evolutionary grade of those animals that comprise today’s snakes, tuatara, lizards, and crocodilians among others. It examines the life of their extinct relatives as well as the long-gone ancestors of the present-day mammals. Because of their diversity and evolutionary history, it is important to realize that the level of validity in this class has not been supported universally in various scientific circles. However, the practice has remained to be used by many laymen and biologists especially those in the media. Herpetology is the kind of study that specializes in reptiles, examining their history and evolutionary trends. It also examines the life of amphibians with the same motive as that highlighted above, for reptiles (Ariefiandy et al.67). Some of the earliest known reptiles originate from around 315M years. This happened especially in the Carboniferous times. Some of the early examples of amphibians include Westlothiana and Hylonomus, Casineria, which according to history may be some of the only known land-dwelling amphibians (Ariefiandy et al. 70). Besides existing amphibians, many diverse groups have now become extinct due to many reasons including mass extinctions. However, the point of interest is to understand how the present day reptiles behave in their natural habitats, something that can help in the development of effective management and conservation approaches and strategies. Reptiles are often described as being tetrapod vertebrates, which means, creatures that have four limbs or descended from their ancestors that were four-limbed like snakes. As compared to amphibians, reptiles often lack the water-based larval stage. Many of the common reptiles are high oviparous. However, there are various species of squamates, which are viviparous. This is the same as some of the extinct clades that lived in water. For these reptiles, their fetus developed in their wombs (Goldstein et al. 269). They were secured in the placenta as compared to the egg shell, which is common with many of the well-known reptiles. Just like amniotes, the eggs of reptiles are protected by special membranes, which provide transport and protection. This adaptive feature enables reptiles to reproduce on dry land. Some of the well known viviparous reptile species take care of their fetus in various forms of their placenta, which is almost similar to those seen in mammals. Some reptiles give care to their hatchlings for the first few weeks or months before they can support themselves. Extant reptiles exist in various sizes. They range from highly tiny geckos that measure up to around 17 mm to the large saltwater crocodiles that can be as long as 6 meters with over 1,000 kgs (Ariefiandy et al.71). All these reptiles have different ways in which they manage their lives from mating, reproduction, feeding and even death. The following diagrams present some of the well-known reptiles. Fig 1. Some of the commonly known reptiles (Ariefiandy et al. 77) 2. Historical background Historically, reptiles are said to have arisen around 300M years ago, where they evolved from their salamander-like ancestors (Laver et al. 149). Reptiles are a representative of a cycle of life that transits from aquatic life to a complete terrestrial life. However, some reptiles have gone back to stay in the water and may sometimes resurface on land for a short while. The fact that reptiles’ eggs resistant to water and hard waterproof skins mean that they can afford to live in places where animals in the amphibian category cannot manage. Currently, the number of recognized reptile species exceeds 8,700 with large majorities belonging to the Squamata group. This group comprises of snakes, lizards and other worm-like amphisbaenians (Nelson 357). Fig 2. Some facts on Komodo Dragons (Watts et al. 1023). As noted from the foregone discussion, reptiles exist in various sizes, ranging from the tiny geckos to the large giant-like Komodo dragons with fine scales and weight of more than 150 kgs. In reptiles, venom is widely spread, therefore; any reptile animal should be treated with suspicion because one may never know the one that is poisonous. Snakes and some lizards produce irritating sensations from their salivary secretions, which immobilizes and kills their prey (Permanasari 437). Some coral snakes’ poison is so dangerous that can cause heart attacks and cardiac arrests in short durations, leaving the victim dead. However, not all reptiles are poisonous; thousands still co-exist with humans without causing any harm. Reptiles have some adaptive features that are highly remarkable. For instance, the tails of some lizards like crocodiles and Komodo dragons has many uses. The Gila monster that is common in North America’s Sonoran Desert uses its tail for storing energy. This animal’s tail is plump and quite long, something that underpins its adaptive purpose. On the other hand, the African chameleons use their prehensile tails as limbs for wrapping around branches when moving on trees. However, it is fascinating to realize that when reptiles have no use for their tails, they can just do away with it (DAmore and Blumenschine 545). When most reptiles like lizards are attacked, their tails are designed in such a way that they easily fall off. In this regard, the predator is distracted from following after the lizard, living it to get away. Later, the tail grows again for the lizard. Therefore, lizards have an alternative of using their tails or letting it go on such like occasions. 3. Komodo Dragons Komodo Dragons are also referred to as Komodo monitors (Watts et al.1022). They are some of the large lizard species that are commonly found in many of the islands of Indonesia like Flores, Rinca, Padar and Gili Motang. Komodo dragons belong to the family of monitor lizards (Montgomery et al. 548). They are the largest and biggest lizard species that still in existence; they are often very long, measuring up to 3 meters in length. There are individual instances where some Komodo dragons weigh up to about 70 kgs in weight (Laver et al.149). The table below, from Laver et al. (2012) indicates some of the statistics of some of the animals in Komodo National Park regarding their size and weight. (Laver et al.148). One of the suggested reasons for these animals’ large size is island gigantism. In this regard, it is often believed that no carnivorous animals have the ability to fill the existing niche on those islands that the Komodos live. Recent research has indicated that the relatively large size of the Komodos can be understood as being representatives of relict populations of large lizards (Sulandari et al. 67). These lizards are said to have once existed on the islands of Australia and Indonesia but died after Pleistocene. Some of the fossils of the Komodos have been discovered in Australia, with further research indicating that they existed more than 3.8M years. The body of this animal continued to remain stable, living on the Flores Island. Fig 4. Komodo Dragons (Ariefiandy et al. 77) Due to their enormous size, Komodo dragons have a high level of dominance in their respective ecosystems. They often hunt and their prey, which comprises of various mammals, birds, and even some invertebrates. Some ecologists have claimed that the Komodo dragons have highly venomous bites that kill their prey before they can feed on them. Two glands have been identified in the dragon’s lower jaw, which often secret many toxic proteins. On many occasions, the biological importance of these proteins has elicited a lot of dispute among ecological researchers. However, the gland shaves have been known to produce an anticoagulant. It is important to recognize the fact that group haunting as demonstrated by these reptiles is one of the utmost remarkable in the world of reptiles. For big reptiles, their diet often comprises of large deer, since they also consume carrions in considerably large amounts (Nelson 351). Occasionally, these dragons often attack people, especially in areas around West Manggarai Regency, an area that they are known to live. 4. Behavior and Ecology Komodo dragons seem to prefer places that have hot and dry climates. In this regard, they are common in open and dry grasslands, in the tropical forests and savanna that are found at low elevations. Being an ectotherm animal, the Komodo dragons are very active during the day when they do most of their hunting. However, these animals have individual levels of nocturnal activity. The Komodos are known to be highly solitary animals, meeting only for breeding and eating. They manage short sprints of about 20 km/h (Sulandari 66). They can dive in the water to a level of about 15 ft. and can climb trees effectively when they are still young using their sharp and strong claws. The Komodos have the ability to stand on their hind legs whenever they may want to catch their out-of-reach prey. In this regard, they use they tail for support while standing on their hind legs (Nelson 357). As they begin to mature, their enormous size makes it impossible for them to climb on trees, and their claws become useful and powerful weapons. Komodos often dig holes that they use for shelter. These holes can go up to a depth of about 1-3 m in width. In digging these holes, they use their claws and forelimbs. Due to their large size, the Komodos can conserve their body heat by sleeping in these burrows. In this case, they can minimize or stop basking in the sun in the early morning. Such Komodos gets from their burrows to hunt, which takes place mostly in the afternoons. (Nelson 364) During the hottest daytime, they like resting under tree shades. The areas that these animals use for shelter can be identified by droppings and do not have vegetation. In many instances, these places are strategic locations from where they can identify and ambush their prey. 5. Hunting and Diet From the predetermined discussion, it is evident that the Komodos are carnivores. Since they sometimes feed on carrions, they have an ability to attack and kill live prey when they use stealthy approaches like other carnivores do. Whenever the desired prey gets close to the Komodos ambush site, the dragon charges fast at it, going for its underside or throat. During hunting, the animal has an adamant and effective sense of smell, which it uses in identifying its prey. This sense of smell enables the dragon to identify dead or live prey from a distance of about 9.5 km (Sulandari 69). On several occasions, the Komodos have been seen knocking their prey like large deer and pigs using their tails, which are strong enough to manage the process. While eating, the Komodos often tear large pieces of meat from their prey and swallow them. In doing this, they use their forelimbs to hold the rest of the prey on the ground. For small prey that can be the size of goats, the Komodos often swallow them whole. They depend on their flexible skulls, powerfully articulated jaws and expandable stomachs, which make it easy for them to swallow their sizeable prey without any problems. During feeding, the Komodos try to avoid the intestines of their prey and vegetable contents from their stomachs. They use their copious saliva that they produce in lubricating the food during swallowing, a process that takes about 15-20 minutes to complete in the case of a small goat. In speeding up the rate of swallowing their prey, the Komodos often ram their prey on trees so that they easily flow in their throats. There are instances when they have ended up knowing down trees in the process of ramming their carcass on them. This process helps the animals to avoid suffocation in the process of swallowing. As it gulps its prey, it manages its breathing by using its tongue, which has a small tube beneath it. In this regard, the tongue of the Komodos is connected to its lungs. After the animal east about 80% of its entire body weight, it drags slowly to the sun so that the digestion process can speed up (Goldstein et al. 269). When the food is left to stay in the dragon’s body for long, it can begin to rot, producing chemicals that can poison it. Therefore, it has to ensure that it lies in the sun so that the process of digestion can increase. Due to their slow rate of metabolism, large Komodos often survive on about 12 meals in a year. After the digestion process has completed, the dragon often regurgitates many horns, teeth, and hairs that are referred to as gastric pellets. These pellets are often covered in the animal’s malodorous mucus. After the process of regurgitating gastric pellets, the dragon rubs its entire face on brushes or dirt so that it can get rid of mucus, which suggests that the animal does not relish the kind of smell from its secretions. During the feeding process, large dragons are the first to feed while the small or young ones follow in that respective. In many instances, the large male dragons are aggressive in the process of asserting their dominance (Goldstein et al. 270). In the submission, the other smaller males often make rumbling hisses and various body movements, however; those dragons that are of equal size can resort to wrestling to identify the winner. Those that lose the fight are sometimes killed and devoured by their victors. As noted in the foregone discussion, the diet of the Komodo dragons comprises of smaller reptiles like Komodo dragons, invertebrates, eggs of some birds, monkeys, and even water buffalos. Young Komodos like feeding on geckos, small insects, and mammals among other animals that are smaller (Ariefiandy et al. 77). On special occasions, they sometimes consume humans especially those that find themselves in their locations accidentally like those that are drunk. Fig 45 People killed by Komodo dragons (Sulandari et al. 73) They can also feed on human corpses when they dig them from very shallow graves. The habit of digging up graves made residents of Komodo village in Indonesia to change their graveyards from shallow sands to clay. After they bury their loved ones, they also pile heaps of stones on them so that the dragons cannot find them. It is believed that it is these dragons that could have evolved to eat the long extinct stegodon, which were the dwarf elephants. These elephants are said to have existed on the Flores Island as reported by Jared Diamond, a once renowned evolutionary biologist (Montgomery et al. 550). Fig 6. Flores (Sulandari et al. 71) 6. Reproduction Male Komodos often grow to become enormous and bulky compared to females. In this regard, it is important to understand that there are no morphological differences, which identify the sexes. However, there exists one important subtle clue that can help make the difference. This difference relates to the way scales are arranged just before the cloaca. Researchers have explained that finding sexing Komodos has remained to be a significant challenge. For the dragons, they often find little trouble in recognizing who is who. During the time they are feeding on carrions, the chance for courtship often arrives. The males will start moving around the females in the process of getting acceptance for an opportunity to mate (Goldstein et al. 269). For the Komodo dragons, the mating process often takes place in the months of May, June, and August. During this process, many of the large males can be seen embroiled in their ritual combats in the process of questing females for a mating chance. The males often engage in wrestling exercises while standing on their hind limbs supported by their stiff tails (Watts et al. 1021). They often grab each other using their forelimbs while attempting to throw each other on the ground. During these fights and wrestling, blood is often drawn, with the losers choosing to run away or remaining motionless on the ground. In some instances, the victors often eat their opponents after killing them. Additionally, the winning males get the chance to dominate the available females. The winning males starts the courtship process by flicking its tongue on the snout of the female Komodo and then over the body of the female. The fold and the temple found between the rear legs and torso are some of the ideal spots during the mating process. Stimulation of the mating process is in the chemical and physical form through secretions from the skin glands. Before the copulation process can happen, the male is expected to evert his hemipenes that are located within its cloaca. The cloaca is found on the male dragon’s tail at the base end. After that, the male crawls slowly on the female’s body, inserting one of its two hemipenes into the females cloaca (Watts et al. 1021). The insertion of one or all the hemipenes depends on the location of the female Komodo. However, it should be noted that whether all of the hemipenes or one of them is inserted, the effect is the same, they cause an active copulation. After mating, the female Komodo can lay up to 30 eggs in the month of September (Watts et al. 1022). It is worth noting that the delay the animals sometimes seem to have in their mating help in avoiding extreme temperatures during the extremely dry months. Additionally, those eggs unfertilized get another chance for fertilization during the subsequent mating sessions. The female Komodos often lay their eggs in the depression that they dig on the slopes of hills. They also use the pilfered nests that are made by Megapode birds (Sulandari et al. 73). These birds are chicken-sized, and they dwell on land. When they are laying their eggs and nesting, they make their nests with twigs measuring up to 1 m in height and about 3m across. When the Komodo eggs are incubating, the females often lie on their nests so that they can protect them from predators and its future offspring. However, science researchers have so far not come across any evidence of parental care for the newly hatched young Komodos. 7. Conclusion It is significant to understand that the ecological life of Komodos has made them some of the highly researched reptiles in contemporary times. Being that they are among some of the animals under the threat of extinction, a lot of conservation and management efforts have been developed to ensure that these reptiles are taken care of. These efforts have seen the Indonesian government and many other animal researchers devise various sensitization programs to have people appreciate these animals (Montgomery et al. 549). From the time the young Komodos are hatched all the way, until they mature, they are carefully looked after in their natural habits so that they are not devoured while growing. These animals have been a major source of heritage for the Indonesians, with many people touring the country to understand their history and their way of life. It is significant to realize that all reptiles have important social and economic significance for communities and society that take care of them (Laver et al. 154). Many of the people that have systems to take care of these animals benefits from local and domestic tourism when people come to see them. Therefore, a lot of efforts should be invested in research on how best management and conservation efforts can be undertaken. In this regard, adherence to these efforts can enable these animals to be well preserved for the future generations (Permanasari 438). Many of these generations may never have the chance to see these animals but will only read them from books and journals. Works Cited Ariefiandy, A., D. Purwandana, C. Natali, M. J. Imansyah, M. Surahman, T. S. Jessop, and C. Ciofi. "Conservation of Komodo Dragons Varanus Komodoensis in the Wae Wuul Nature Reserve, Flores, Indonesia: A Multidisciplinary Approach." International Zoo Yearbook Int. Zoo Yb. (2014): 67-80. Print. DAmore, Domenic C, and Robert J. Blumenschine. "Komodo Monitor ( Varanus Komodoensis ) Feeding Behavior and Dental Function Reflected Through Tooth Marks on Bone Surfaces, and the Application to Ziphodont Paleobiology." Paleobiology. 35.4 (2009): 525-552. Print. Goldstein, Ellie J. C, Kerin L. Tyrrell, Diane M. Citron, Cathleen R. Cox, Ian M. Recchio, Ben Okimoto, Judith Bryja, and Bryan G. Fry. "Anaerobic and Aerobic Bacteriology of the Saliva and Gingiva from 16 Captive Komodo Dragons (Varanus Komodoensis): New Implications for the “bacteria As Venom” Model." Journal of Zoo and Wildlife Medicine. 44.2 (2013): 262-272. Print. Laver, Rebecca J., Deni Purwandana, Achmad Ariefiandy, Jeri Imansyah, David Forsyth, Claudio Ciofi, and Tim S. Jessop. "Life-History and Spatial Determinants of Somatic Growth Dynamics in Komodo Dragon Populations." PLoS ONE (2012): 145-154. Print. Montgomery, Joel M, Don Gillespie, Putra Sastrawan, Terry M. Fredeking, and George L. Stewart. "Aerobic Salivary Bacteria in Wild and Captive Komodo Dragons." Journal of Wildlife Diseases. 38.3 (2002): 545-551. Print. Nelson, J Lee. "Faculty of 1000 Evaluation for Parthenogenesis in Komodo Dragons." F1000 - Post-publication Peer Review of the Biomedical Literature (2007): 345-365. Print. Permanasari, Indira. "Saving the Komodo Dragons." History, Culture, Politics The Indonesia Reader (2009): 435-39. Print. Sulandari, Sri, Moch Samsul Arifin Zein, Evy Ayu Arida, and Amir Hamidy. "Molecular Sex Determination of Captive Komodo Dragons (Varanus Komodoensis) at Gembira Loka Zoo, Surabaya Zoo, and Ragunan Zoo, Indonesia." HAYATI Journal of Biosciences HjB (2014): 65-75. Print. Watts, Phillip C and Kevin R. Buley, Stephanie Sanderson, Wayne Boardman, Claudio Ciofi, and Richard Gibson. "Parthenogenesis in Komodo Dragons." Nature (2006): 1021-022. Print. Read More