New rat species find sheds light on Philippine mammalian diversity

A recent report, published by the Biological Society of Washington, details the discovery of a new rat species, Batomys uragon, on the mountainous island of Luzon in the Philippines.

A member of the research team, Lawrence Heaney of the Field Museum of Natural History in Chicago, responded to Mongabay’s request for an interview on the significance of the discovery and B. uragon’s conservation future.

Mongabay: What is so unique about the discovery of the new Batomys species?

Lawrence Heaney: This new species, Batomys uragon, is a member of a group of mammals called “cloud rats” that live only in the Philippines — a branch on the tree of life that occurs nowhere else. This discovery brings the number of cloud rat species to eighteen, twelve of which occur on Luzon Island, the largest island in the Philippines.

These animals form an adaptive radiation, [in a] habitat restricted to the [islands of the] Philippines, much the same as lemurs are restricted to Madagascar. Cloud rats feed on plant material in the canopy of rainforest that grows on mountains above 1,000 meters [3,280 feet] in elevation. They’re rodents, distantly related to familiar pests like rats and mice, and in appearance quite similar to squirrels or chinchillas.

Mongabay: Where, when, and how was the discovery made?

Lawrence Heaney: Members of our research team first encountered this species in 1988, on Mt. Isarog, a dormant volcano in southern Luzon designated as a national park. We were conducting the first, thorough survey of the mammals of Mt. Isarog. Batomys uragon is now the fourth species of mammal [to be found] that lives only on that mountain. We were unable to recognize this species as distinct until we had conducted studies of mammals in the mountains of northern Luzon, where two other species of Batomys were known, but so poorly represented in museum research collections that we could not make crucial comparisons using either anatomical or DNA samples.

Mongabay: Who was involved in the project?

Lawrence Heaney: The team involved in this study included Danny Balete, a biologist from the Philippines who has been collaborating with the Field Museum of Natural History for over 20 years; Eric Rickart, Curator of Vertebrates at the Natural History Museum of Utah; Larry Heaney, Negaunee Curator of Mammals at the Field Museum; and Sharon Jansa, Curator of Mammals at the Bell Museum of Natural History, University of Minnesota. Larry, Eric, and Danny conducted the field and morphological studies while Sharon conducted the DNA analyses.

Mongabay: Who funded the research?

Lawrence Heaney: Our initial funding came from the U.S. National Science Foundation and the Smithsonian Institution. More recently, we received support from the Negaunee Foundation, a family foundation in Chicago, and the Brown Fund for Mammal Research at the Field Museum.

Mongabay: What methods were used to identify and classify the new species?

Lawrence Heaney: We conducted detailed studies of the anatomy of Batomys using preserved specimens housed in the research collections at the Field Museum, and at the U.S. National Museum of Natural History. Tissue samples were taken from the voucher specimens at the time they were collected, both in 1988 and more recently, and these were used for DNA-based studies of genetic variation. The two approaches — morphological and genetic — yielded very similar results, giving us confidence in our decision to propose this as a distinct species, and not simply to view it as an isolated population of a previously known species.

When our studies of these animals are completed, a portion of the specimens, including the all-important holotype specimen of the new species, will be deposited at the National Museum of the Philippines.

Mongabay: How significant is this discovery to the conservation of forested areas in the Philippines?

Lawrence Heaney: Mt. Isarog supports the largest remaining area of high-elevation forest in southern Luzon, making it crucial for conservation of biological diversity. It also forms the headwaters for several rivers that provide much of the water for agriculture and urban use in that region of the country. Mt. Isarog can be struck by many typhoons each year, as it is within the so-called “typhoon alley” in the Philippines, and may receive as much as 8 meters, perhaps 10 meters [26 to 32 feet], of rain in a year.

Maintaining the forest to protect the watershed is critically important for biodiversity and the human population. Luzon is one of the most densely populated islands in the world, and several large cities lie near Mt. Isarog.

Mongabay: Has this discovery opened new opportunities for research?

Lawrence Heaney: The discovery of Batomys uragon is part of a long-term, intensive study of the evolution, ecology and conservation of mammalian diversity in the Philippines that we began in the 1980s.

The paper that describes this species is one of the necessary building blocks allowing us to develop a comprehensive understanding of the origin of what currently appears to be the greatest concentration of unique mammalian diversity in the world. Some other countries have more species, and some have more endemic species, but those countries are much larger, while the Philippines has the greater diversity. Our project is asking why this is so, how it came to be, and what we need to do to assure its permanent survival.

Mongabay: Does this discovery have any economic impact for the Philippines?

Lawrence Heaney: Protecting the remaining forest in the Philippines is a matter of national economic importance; floods and erosion are among the most destructive forces now at work. Since a reliable source of clean, safe water is essential for any society, protecting the remaining forest is good for social stability and progress. Discovering and protecting unique biodiversity often provides a spark, or point of leverage, for protecting the habitats where the animals live. And everyone loves to learn that there is something globally unique that lives in their backyard.

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The fact that the discovery of a new species was made inside a national park reaffirms that conservation is essential and works for the protection of biodiversity. National parks and similarly protected areas are not just scenic destinations for human connection with wildlife; they are important laboratories for the study of natural history to fulfill the need to educate society on the benefits of conserving the environment and maintaining the diversity of life.

“Many people have an inherent love for nature,” Heaney concludes, “and discovering new species and making the information available to people everywhere helps to promote an understanding, appreciation and enjoyment of nature. When people understand and enjoy something, they may act to protect it.”