A new species of mountain-dwelling shrew was recently discovered in Mt. Mantalingahan in southern Palawan.
In a paper published this May in the Journal of Mammalogy, researchers at the Field Museum in Chicago identified the species as Palawanosorex muscorum, also known as the Palawan moss shrew.
The Palawan moss shrew is a “distinct species” with a slender, pointed snout and dark coat, and was first spotted in 2007 by the late Danilo “Danny” Balete, the Field Museum’s field survey leader and research associate.
Unlike other shrews, its tail is covered in dense fur rather than visible scales. With broad forefeet and long claws, the Palawan moss shrew digs through humus in search of its favorite snack: earthworms.
The species’ home, Mt. Mantalingahan in southern Palawan, is habitat to three unique mammal species, including the shrew.
“There are entire countries that don’t have three unique mammal species – so for there to be three species on one mountain, on one island, in one country is really something,” Field Museum’s Larry Heaney stated in a news release.
Heaney described Mt. Mantalingahan as one of the Philippines’ “sky islands” or isolated mountaintops home to distinct habitats separate from the lowlands and neighboring mountains.
“Sky islands” create hubs of biodiversity, allowing for multiple ecosystems – and, by extension, a wider range of species – to coexist within a single geographic area. It might help explain why mammalian biodiversity thrives in the Philippines specifically, according to the Field Museum.
Researchers say this new shrew species found around 5,000 feet above sea level gives them some clues as to what makes the Philippines an ideal environment for mammals. It would also help them figure out how the Philippines’ many mammal species got there in the first place.
“There could be many new species on these high mountainous regions in the Philippines, but because they are so high, and hard to get to, knowledge of their existence is awfully limited,” Heaney said.
For those who live and work in Palawan, the country’s largest province, protecting the Palawan moss shrew and Mt. Mantalingahan hits even closer to home – it’s a matter of personal and economic safety.
Mt. Mantalingahan, in addition to being a “sky island,” functions as a crucial watershed, regulating the flow of water in Palawan through natural processes.
In Mt. Mantalingahan’s case, humus – the low-density mountainous soil the Palawan moss shrew digs through – acts as a sponge, holding water from the frequent rainfall high-elevation places tend to experience.
Deforesting this mountain and other “sky islands” bears grave repercussions. “That’s where most of the water comes from that people in the lowlands depend on,” Heaney warned.
“In deforested areas, when a typhoon hits, it kills thousands of people and animals, and destroys buildings. And if water isn’t being released slowly from the mountains, you’ll have less of it in the dry season, causing drought. If you want to protect your watersheds, you’ve got to protect your habitats.”
Built on agriculture, fishing, and tourism, Palawan’s economy depends greatly on the steady flow of water – from where the Palawan moss shrew lives, to where nearly three-quarters of a million people live.
Today, much of the Palawan moss shrew’s habitat remains undisturbed by human activity. And both it – and we – stand to benefit from keeping it that way.
“Sometimes it’s presented that environmental concerns and economic development are at odds with each other. That’s false,” Heaney asserted. “Smart economic development means not creating situations that cause mass damage as a result.”
Beyond the economic implications of the shrew’s discovery, Heaney hopes the new species sparks excitement among the Filipino and international scientific communities, which in turn can help encourage research, conservation, and advocacy efforts.
“People in the world get excited about the cool things that live in their country,” Heaney said. “The fact that the Philippines is such a unique hotspot for mammalian diversity is something people should be aware of, something that people can take pride in.”