Field Museum curator helps discover 7 species of mice

Scientist among team reporting discovery in Philippines

June 29, 2011|By Kelly April, Tribune reporter
  • Lawrence Heaney, curator of mammals at Chicago's Field Museum, shows off the seven new species of mice that he and colleagues found in the Philippines.
Lawrence Heaney, curator of mammals at Chicago's Field Museum, shows off the seven new species of mice that he and colleagues found in the Philippines. (Nancy Stone, Chicago Tribune)

A team of scientists working in the cloud forests of the Philippines have found what they describe as a very small but new branch on the Tree of Life.

Finding a single new species of mammal is a rare event, but Lawrence Heaney, curator of mammals at the Field Museum, reported identifying seven new species of mice, all of them part of a mouse subgenus not known before to science.

"It has been at least 30 to 40 years since seven new mammal species were discovered in a single publication," said Heaney, whose findings appeared in the Field's peer-reviewed journal, Fieldiana. "It is rather common for insects, mites and fish, but not common for mammals."

In the 30 years Heaney and a team of Filipino scientists have been studying the highland cloud forests and lowland rainforests of Luzon, the country's largest island, they have described 17 new mammals found nowhere else. Heaney paints a picture of a biologically rich country boasting a diversity of unique species.

"We're finding new species in the Philippines a lot faster than we can write the descriptions," Heaney said. "We've got lots of them lined up. I would hesitate to make a guess as to how many there will be when we finish what we hope to do."

White-haired and bespectacled, Heaney keeps preserved specimens of the mice in his office and shows them off like a proud father. Their genus, Apomys, is named for Apo, the highest mountain in the Philippines.

The brown mice live on the floor of Luzon's cloud forests, where it's too cold for ants and termites, the usual staples of mouse diets. Instead, these species eat earthworms, fungi and seeds.

To trap some of the mice, Heaney and his team used freshly sliced coconut, lightly fried and smothered in peanut butter. Others were caught with earthworms and brass safety pins, like fishing hooks for mice.

Genetic testing suggests the mice on Luzon have a common ancestor, Heaney said, but they evolved into different species over millions of years, as differences in their local habitats favored some traits over others.

"It's the classic story of Darwin's finches, with their beak shapes. But in the Philippines, it's mice, not finches," Heaney said.

Most of the mammals found on Luzon are mice, bats and shrews. Because the Philippines' islands have never been connected to mainland Asia, their ancestors probably arrived millions of years ago, drifting from the mainland aboard mats of vegetation and hollow logs, propelled by typhoons, scientists say.

The discoveries of new species have fueled efforts to protect highland forests on Luzon, which have abundant rainfall and serve as the island's primary watersheds. Logging and other destructive practices in the forests are threatening that water supply, which is crucial to sustaining Luzon's 40 million people.

Heaney said he has seen three of the areas where the mice were found become protected areas, and two more areas were recently added to the list for consideration.

"When we announce the discovery of new species, people get really excited about that," he said. "It helps move things toward interest in protecting the habitat where the animals live. Those are the watersheds (residents) depend on. Protecting these animals is a good idea for them."