Dragon surprise

There are now so few areas of natural environment in the world that have not been subject to biological survey or disturbance so the discovery of new species in recent expeditions to some of these regions has been proving remarkable, although large 'new' vertebrates are now increasingly rare. However, a recent analysis of material collected from lizard specimens in the northern Philippines has led to the discovery of a new species of large monitor lizard. A team led by Luke Welton at the University of Kansas, and researchers from the Philippines and the Netherlands, reporting in the Royal Society's Biology Letters (published online), have carried out research on the morphology and mitochondrial and nuclear DNA sequences to determine the taxonomic distinctiveness of a monitor lizard found only in the central and northern forests of the island of Luzon, distinct from the lizards found in the southern part of the island and some neighbouring islands. " How could such a large-bodied monitor lizard have escaped the notice of the many biologists that have worked in the northern Philippines? " Luzon is the major northern island of the Philippines, heavily populated and cultivated in the south but with remote mountain forests in the north. Monitor lizards occur throughout the Asian tropics and vary greatly in habitat, size and morphology from the smallest at less than 25 centimetres in length to the komodo dragons which can reach more than three metres. Fewer than 10 new species of monitor lizard have been described in recent years, most of which have been smaller forms. Philippine species of the family Varanidae include five species — three water monitors and the world's only two frugivorous species. These two species are rare and difficult to study. Shy and elusive, Varanus olivaceus is found in the lowland forest of southeastern Luzon and two smaller eastern islands. V. mabitang is a poorly known species, endemic to a different offshore island. Both species are considered heavily threatened, primarily as a result of habitat destruction. The newly described species comes from the forested region of the Sierra Madre mountains in the north of the island. The researchers have designated it as V. bitatawa. " Discovery of a highly distinctive new species of monitor lizard from the heavily populated and highly deforested Luzon island comes as an unprecedented surprise, " the team write. " How could such a large-bodied monitor lizard have escaped …