Varanus bitatawa, A New Monitor Lizard


The Philippines archipelago contains more than 7,100 islands and includes 17 active volcanoes that covers 0.29 million km² in the western Pacific. The archipelago was formed from isolated fragments of continents and islands, some dating back to 30-50 million years ago. Its flora and fauna contain elements from Taiwan, Palawan, and Borneo and show strong affinities with the Sunda Shelf fauna. But the Philippines have a huge endemic fauna, species that are found nowhere else. Historically most of the islands were covered in rain forest, dominated by huge trees of the family Dipterocarpaceae. At higher elevations, montane forests and mossy forests consist mostly of smaller trees; and some areas of the islands contain seasonal forest, mixed forest, savanna, and pine-dominated cloud forest. Thus it is not surprising that the Philippines contain an exceptionally diverse fauna with many still undescribed plants and animals. Luke Welton and colleagues have recently described a new species of giant (2 m), secretive, frugivorous, forest monitor lizard, Varanus bitatawa from the northern Philippines on the island of Luzon. Morphology and DNA data suggest the new species is closely related to Varanus olivaceus, known from southern Luzon and nearby islands. The new species appears to be restricted to forests of the central and northern Sierra Madre mountain range, separating from the range of V. olivaceus by more than 150 km. The name bitatawa is derived from the Agta tribal peoples’ common name for the lizard. The discovery of new large animals is useful for the conservation of the areas they in habitat because it draws attention to biodiversity hot spots and engenders public and political support for protecting biodiversity.

Luke J. Welton, Cameron D. Siler, Daniel Bennett, Avin Diesmos, M. Roy Duya, Roldan Dugay, Edmund Leo B. Rico, Merlijn Van Weerd, and Rafe M. Brown. 2010. A spectacular new Philippine monitor lizard reveals a hidden biogeographic boundary and a novel flagship species for conservation Biology Letters 2010 6:654-658.