Thursday, February 27, 2014

[Herpetology • 2010] Varanus bitatawa • A Spectacular New Philippine Monitor Lizard reveals a Hidden Biogeographic Boundary and a Novel Flagship Species for Conservation

Northern Sierra Madre forest monitor Varanus bitatawa
Welton, Siler, Bennett, Diesmos, Duya, Dugay, Rico, Van Weerd & Brown 2010

As humans continue to explore the last uncharted regions of the planet, discoveries of previously unknown species of large vertebrates have become infrequent. Here, we report on the discovery of a spectacular new species of giant, secretive, frugivorous, forest monitor lizard (Genus: Varanus) from the forests of the northern Philippines. Using data from morphology and mitochondrial and nuclear DNA sequences, we demonstrate the taxonomic distinctiveness of this new 2 m long species and provide insight into its historical biogeography and systematic affinities. Our molecular phylogenetic analyses indicate that the new species is closely related to Varanus olivaceus (from southern Luzon and nearby islands), but it differs from this and other varanids with respect to characteristics of scalation, colour pattern, body size, anatomy of the reproductive organs and genetic divergence. The new species appears to be restricted to forests of the central and northern Sierra Madre mountain range; it is separated from the range of V. olivaceus by a more than 150 km stretch that includes at least three low-elevation river valley barriers to dispersal. This discovery identifies a seldom-perceived biogeographic boundary and emphasizes the need for continued biodiversity research in the megadiverse conservation hotspot of the Philippines. It is anticipated that the new species will serve as an important flagship species for conservation efforts aimed at preserving the remaining forests of northern Luzon.

Keywords: biodiversity, conservation hotspots, flagship species, frugivory, Sierra Madre, Varanus

Varanus bitatawa sp. nov.

Etymology: The specific epithet is derived from bitatawa, the Agta tribespeoples' common name for the new species.

One of the first photographs in life of the newly discovered (Welton et al. 2010)
Varanus bitatawa (KU 322188) from Barangay Dibuluan, San Mariano.

Luke J. Welton, Cameron D. Siler, Daniel Bennett, Arvin 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. 6 (5): 654–658. doi:

Brown R, Siler C, Oliveros C, Welton L, Rock A, Swab J, Van Weerd M, van Beijnen J, Rodriguez D, Jose E, Diesmos A 2013. The amphibians and reptiles of Luzon Island, Philippines, VIII: The herpetofauna of Cagayan and Isabela Provinces, northern Sierra Madre Mountain Range. ZooKeys. 266: 1. DOI: