Jun 7, 2019

When news about weird endemic species come up, most of us are conditioned to expect the worse: This species is dead, or dying out, or there’s only less than 50 known in the wild. (Think the Cebu damselfly) This is why news of a new endemic species published in Oxford’s Journal of Mammalogy was so refreshing. Two new species of shrew rats endemic only to Luzon have recently been discovered: Rhynchomys labo and Rhynchomys mingan, which are found in  Mt. Labo and Mt. Mingan, respectively. “These discoveries highlight the importance of isolated highland areas in the historical diversification of Southeast Asian murines, and as current centers of endemism,” the journal article states.

The R. labo and R. mingan are a kind of rhynchomys, which are “characterized by an extremely long rostrum, long, slender mandibles bearing thin, saber-like lower incisors, greatly reduced molars, and a suite of other characters that reflect specialized diet and behavior,” the journal describes. They’re called tweezer-beaked rats because of this, and they’re a notable example of convergent evolution. Including the R. labo and R. mingan, there are only six known rhynchomys species in the world, all found in Luzon. The discovery of these new species (and the rhynchomys genus in general) was led by Danilo S. Balete, “one of the best field biologists in the Philippines,” who unfortunately passed away in 2017. Thankfully, his co-authors were able to continue the research that he started.

Drawing of the Rhynchomys labo courtesy of Velizar Simeonovski, Field Museum

In a later science press statement, lead author Eric Rickart, a curator of the Natural History Museum of Utah at the University of Utah, colorfully describes the species. “They’re quite bizarre. They hop around on their sturdy hind legs and large hind feet, almost like little kangaroos. They have long, delicate snouts, and almost no chewing teeth.” Co-author Larry Heaney of the Field Museum added: “They’re very docile, very cute. Their fur is short and very, very dense, like a plush toy. They make little runways through the forest and patrol these little trails, day and night, looking for earthworms.”

“The Philippines boasts more unique species of mammals per square mile than anywhere else on Earth,” the article describes. “Just about every time we’ve gone to a new area of Luzon with mountains, we’ve discovered that there are unique species,” Rickart expounds.

Drawing of the Rhynchomys mingan courtesy of Velizar Simeonovski, Field Museum

However, as all of us Filipinos know, the Philippines’ forests and eco-diversity are in grave danger. “The Philippines is one of the most severely deforested countries in the tropics and most deforestation has happened in the last 40 years,” says Peter Walpole of Environmental Science for Social Change.

This is why the Journal of Mammalogy feature ends on a somber note, as it details the conservation status of the animals. While the animals thankfully live in “montane and mossy forest habitats that have minimal anthropogenic disturbance,” that doesn’t mean they’re free from danger. “All areas of highland habitat, and particularly those supporting endemic species, require protection from direct overexploitation of forest resources and indirect threats posed by geothermal development and mining activities. Protection of these areas would have added socioeconomic benefit in maintaining crucial watershed functions in this region of frequent typhoons.”


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TAGS: Journal of Mammalogy new species nolisoli.ph northern luzon Rhynchomys labo Rhynchomys mingan