Mangrove monitor

Species of lizard

The mangrove monitor, mangrove goanna, or Western Pacific monitor lizard (Varanus indicus) is a member of the monitor lizard family with a large distribution from northern Australia and New Guinea to the Moluccas and Solomon Islands. It grows to lengths of It is also known as wbl yb in the Kalam language of Papua New Guinea.

The mangrove monitor was first described by the French herpetologist François Marie Daudin in 1802. The generic name Varanus is derived from the Arabic word waral (ورل), which translates to English as "monitor." Its specific name, indicus, is Latin for the country of India, but in this instance it relates to Indonesia or the East Indies, where the animal was first described. More research is being done on possible future species within this complex, not surprisingly, since it has had over 25 different scientific names since it was first described.

The mangrove monitor's range extends throughout northern Australia, New Guinea, and the Solomon Islands, where it inhabits damp forests near coastal rivers, mangroves, and permanent inland lakes. It also occurs on the Moluccan islands of Morotai, Ternate, Halmahera, Obi, Buru, Ambon, Haruku, and Seram in Indonesia. Within this range of thousands of miles across hundreds of islands are large variations in size, pattern, and scalation.

The monitor's body is dark green or black in color and covered with golden yellow spots, with light coloration on the top of its head and a solid, cream colored belly lacking dark markings. The mangrove monitor attains different sizes in different parts of its range, but seldom if ever exceeds 1.3 m in total length. The tail is almost twice the length of the body and laterally compressed to aid in swimming. Like the rest of the lizard's body, it is covered with small, oval, keeled scales. The mangrove monitor possesses a Jacobson's organ, which it uses to detect prey, sticking its tongue out to gather scents and touching it to the opening of the organ when the tongue is retracted. The presence of this gland probably enabled the monitors to reach new islands and aid in its dispersal throughout the Pacific. In some parts of its range, it is known to eat juvenile crocodiles. The first successful captive breeding of this species was at the Philadelphia Zoo in 1993. The Reptilian Zoo in Vlissingen, the Netherlands, was reported to have successfully hatched eggs by a female animal which was not in any contact with a male of the same species.

Humans have introduced the mangrove monitor to a number of Pacific Islands since the 1930s. The Japanese introduced the lizards to the Marshall Islands prior to World War II to eliminate rats; the lizards flourished and soon began to raid the local chicken houses. When American troops arrived, the locals asked them for help in getting rid of the mangrove monitors. The US response was to introduce the cane toad (Rhinella marina) which proved toxic to the lizards. In 1980, trade in over 13,000 monitors was declared. However, in many remote places, they are used as a food source and are killed because of their reputation for preying on domestic animals.