New Giant Monitor Lizard Discovered

How could a colorful, 6-foot-long lizard go undocumented for so long?
Jennifer Viegas
Tue Apr 6, 2010 01:10 PM ET

A "spectacular" new species of giant, secretive, colorful and fruit-eating monitor lizard has been found in a Philippine forest, according to a new study.

The reptile, named the Northern Sierra Madre Forest Monitor Lizard, is 6 feet long, around 22 pounds and brightly colored yellow and black. It is in the same family as the Komodo dragon, the world's largest lizard.

"Rumors of its existence and some clues have floated around among biologists for the past 10 years," co-author Rafe Brown told Discovery News. Brown is an assistant professor in the Department of Ecology and Evolutionary Biology at the University of Kansas, and is curator of herpetology at the university's Biodiversity Institute.

He and his colleagues collected a large adult specimen from a forest at Northeast Luzon Island in the northern Philippines. They studied its anatomy and sequenced its DNA, both of which indicated that the lizard represents a new species. It is described in the latest issue of Royal Society Biology Letters.

"We think that it had not been discovered (before) primarily because of its secretiveness and because few comprehensive studies of amphibians and reptiles have been conducted in the inaccessible forests of NE Luzon Island," Brown said.

The huge lizard spends much of its time high in the trees overlooking the forest floor. Perhaps because of its size and apparent tree-specific body camouflage, it may be wary and cautious about exposing itself to terrestrial predators.

Unlike its Komodo dragon relative, the Northern Sierra Madre Forest Monitor Lizard is primarily a vegetarian, subsisting on Pandanus fruit, figs, Pili nut fruits and the occasional snail.

"We do not think it has a venomous bite," Brown said, thinking of the Komodo's venom. "It is not a carnivore, so it would gain no benefit from being able to deliver venom through its bite."

The researchers believe the animal is a "keystone species," which means it helps trees by eating their fruit. The seeds are prepared for germination after they pass through the lizard's digestive tract and are dispersed via bodily waste.

While the new lizard is closely related to another species, Varanus olivaceus of southern Luzon and nearby islands, Brown and his team think three low-elevation river valleys served as barriers to mixing, keeping each type of reptile distinct.

Eric Pianka, one of the world's foremost experts on Varanus lizards, is an integrative biologist at the University of Texas at Austin. Pianka told Discovery News that this "new monitor lizard is indeed exciting. Who would have ever guessed that a 6-foot-long lizard could go undescribed until 2010?"

Pianka added: "This truly is major news!"

Although the lizard was undocumented until now, local Agta and Ilongot tribes people have known about the animal. They rely on its meat as a major source of protein. Brown, however, thinks the greatest threats to the lizard's population are "deforestation, logging, mining and a lack of knowledge about biodiversity."

"To prevent over-exploitation of biodiverse regions, we must first know what is there," he added.

He and his colleagues have already collected specimens in the region representing at least another 10 species -- mostly lizards and frogs -- unknown to science.

"The Sierra Madre of Luzon is a treasure trove of undescribed vertebrate biodiversity," Brown said. "We suspect that many, perhaps dozens of new species of small vertebrates -- reptiles, amphibians, and possibly birds and mammals -- may await discovery in the forests of the northern Philippines."

http://news.discovery.com/animals/giant-monitor-lizard.html