Wildlife Facts The Monitor Lizard, or locally called “bayawak”, belongs to the family Varanidae, which include the largest lizard, the Komodo dragon. The name "monitor" probably originated from the superstitious belief that Nile monitors warned of the presence of crocodiles. Nile monitors eat crocodile eggs and were therefore often seen near crocodile nesting sites. All monitors are tropical reptiles. What are the species found in the Philippines? The Varanus salvator on display is a water monitor lizard, 1 of only 2 species of monitor lizards found in the Philippines. It is commonly found and widely distributed. It is excessively hunted in the country. Its meat and eggs are considered a delicacy and its skin commands a high price in local and international markets as material for shoes, bags and belts. And in some regions of the world, its various body parts are used as medicinal treatment. The other species of monitor is believed to be endemic and rare. It is also known to be the only omnivorous monitor in the world, eating fruit as well as meat. What do they look like? They are large, grayish or dark brown lizards with yellow spots on the underpart of the animal. Juveniles are more colorful, as these yellow markings tend to diminish with age. They have long necks and an elongated snout. Adults can grow to over 2m long and weigh up to 25kg. Its tail is usually longer than its body. Males are about twice larger than females. Unlike other lizards, the tail of a monitor does not grow back once it is lost. Are they dangerous? Yes, they can be dangerous. They are active lizards that may be aggressive, lashing out with their tails upon the slightest provocation. Even a small monitor can produce a stinging lash with its tail. Its claws are long and sharp. The jaws are very strong. Once they bite something it is very difficult to get them to let go. Where do they live? Monitor lizards are terrestrial or semi aquatic animals, rarely seen in groups. The water monitor prefers to live near water, both fresh and saltwater. They are particularly common in mangroves, beaches, swamps and riverbanks. But they can also be found in grasslands, forests and near cultivated land like rice fields. They usually hide in a burrow built in a river bank. The entrance starts on a downward slope but then increases forming a shallow pool of water. The average length of the burrow is about 9.5 meters, the average depth is about 2 meters. In the burrow, the average temperature is around 26o C. They also climb well, to search for food and to escape predators, using their strong curved claws. The young usually stay in trees for safety. If cornered up a tree, they will jump into the safety of a stream or river. What do they eat? Monitors are carnivorous. They tend to swallow their prey whole, like snakes. Monitors are daytime lizards and actively search for food. They eat carrion (dead and decaying flesh), insects such as grasshoppers, beetles and scorpions; crocodile, birds, eggs, crabs, other lizards, snakes, nestling birds, shrews and squirrels. Species that live in or near water will readily eat fish. Like snakes, they have a forked tongue that they stick in and out regularly to "smell" their prey. How do they swim? Water monitors swim well by keeping their limbs to the side of the body, and propelling themselves through sinuous undulations of the flattened tail. They have even been seen swimming far out at sea and can remain underwater for up to half an hour. But on land they can run fast for their size as they have powerful leg muscles. How do they breed? The males mature when the individual is about 1-meter in size and the female at about 50-cm. The breeding season begins at the start of the rainy season, or from April and lasts until October. Water Monitor Lizards breed rapidly. Mating involves a lot of biting and scratching. Larger females produce a larger clutch than smaller ones, up to 40 eggs a year in 2 or more clutches. Females lay their eggs 4 to 6 weeks after breeding. Eggs are laid in termite mounds, along rotting logs or hollow stumps or in burrows. Eggs take 2.5-10 months or more to incubate. What is their conservation status? Though they are still found in many areas, the water monitor is perceived to be endangered because of the present heavy rate of hunting nationwide. It is often considered a menace to agricultural crops and poultry. The truth is that, being insectivores they play an important role in regulating the number of insects, some of which are injurious to agriculture. They are even considered an important rat control agent in the Micronesian islands. With proper regulation, the water monitor can be a good source of economic income to the people. With breeding and farming, it can be an alternative source of protein, a source of good quality leather without putting pressure on declining numbers in the wild. What are Monitor Lizards?
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