Philippines Island of Mindanao a Biodiversity Hot Spot

From frogs, to snakes to lizards, a specific region of the island is home to more than 100 amphibian and reptile species.

The Caraga region of northeast Mindanao, an island in the southern Philippines, has been identified as the top biodiversity hot spot for amphibians and reptiles in the country, the region boasting more species, for an area of its size, than any other in the Philippines.

That's according to researchers who have just documented 126 species in the area - including an array of frogs, snakes, lizards, turtles and crocodiles - in a new study in the online journal ZooKeys.

The island, with a history of environment loss, thanks largely to illegal logging in the timber-rich location, made for a challenging study subject, in terms of species location and documentation.

"Mindanao is a place where, unfortunately, the original forest cover was more than 85 percent, but now it's down to 6 percent original forest, and 15 percent is second-growth vegetation," said study co-author Rafe Brown, University of Kansas curator-in-charge of herpetology, in a statement.

"Mindanao has extensive mineral resources and forests with valuable timber," Brown explained. "Tropical rainforest soils are also very fertile, making the lowlands attractive to agribusiness. There's been conflict over those resources for hundreds of years."

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Nonetheless, Brown and his colleagues forged on. Their efforts to explore the region paid off, to the tune of cataloging 49 lizards, 40 frogs, 35 snakes, a crocodile and a freshwater turtle.

And what efforts. It's one thing to ponder the number of species and another to actually have to go find them.

"We typically dig around tree trunks looking for animals that live underground," Brown said. "We search rivers and streams, turning over rocks, splitting open decaying logs looking for lizards or frogs. We climb trees, looking for tree-dwelling lizards, or place pitfall traps in the ground to catch lizards and small snakes that live in the leaf litter. We also use sticky traps like people use to catch pests in homes."

Here are a few of the critters Brown and his colleagues documented:

A white-lined water snake (Rhabdophis auriculata auriculata):

A frilled tree frog (Kurixalus appendiculatus):

And this cool, two-spotted flying lizard (Draco bimaculatus):

"The biodiversity is so high in this one pocket of northeast Mindanao, largely because the ranges of so many species in the archipelago overlap in this one area," said Brown. "We knew it was really diverse, but we didn't have a sense of this one area being the bull's-eye, the epicenter of this diversity."

"There is something very special about the unique biodiversity of the Caraga region," added Rev. Fr. John Christian Young, president of Father Saturnino Urios University, which also contributed research expertise to the Mindanao survey. "At the 'center of the center' of southern Philippine biodiversity, our small corner of Mindanao is undoubtedly unique, in need of conservation, and worthy of intensive scientific study."

Top Photo: A male Asian agamid lizard, Bronchocela, photographed from Eye Falls, Mt. Hilong-hilong, Municipality of Remedios T. Romualdez, Agusan del Norte Province. Credit: RMB.

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