Researchers have discovered three new species of forest mice on Mindoro Island, increasing the island’s known endemic mammal species by 33 percent and unveiling its extraordinary biodiversity, according to a study published in the journal Zootaxa.

The findings increase the number of mammal species unique to Mindoro from nine to twelve, potentially making it the smallest known island worldwide to exhibit within-island mammal speciation.

Mindoro, covering about 9,735 square kilometers, rivals biodiversity hotspots like Jamaica and hosts iconic species such as the tamaraw, Mindoro warty pig, and Mindoro shrew.

Led by Filipino biologist Danilo S. Balete, a team conducted surveys from 2013 to 2017 across previously underexplored peaks, including Mt. Abra de Ilog, Mt. Iglit-Baco National Park, Mt. Wood, and Mt. Alibug. Their work expands on earlier studies limited to Mt. Halcon.

Previously, Mindoro was known for one endemic forest mouse, Apomys gracilirostris, noted for its dark brown fur and curved claws.

The newly identified species differ distinctly: one from Mt. Abra de Ilog has a brown back, cream belly, and dark facial mask; another from Mt. Iglit-Baco features white ear tufts; and a smaller species from Mt. Wood and Mt. Alibug has a pale brown belly.

The species, named Apomys minor, Apomys crinitus, and Apomys veluzi, underwent nearly a decade of analysis, including cranial measurements and DNA studies by Filipino and American scientists.

After a decade-long analysis, global researchers and biologists are now recognizing the newly discovered forest mouse as an entirely new species.

Apomys veluzi honors the late Maria Josefa “Sweepea” Veluz, a prominent Filipino mammalogist.

The study reveals that about 4.7 million years ago, an ancestral mouse population from Luzon reached Mindoro, diversifying across its mountainous “sky islands” into four distinct species by 1.3 million years ago.

The speciation reasserts the Philippines’ role as a global biodiversity hotspot.

The researchers noted the importance of naming Apomys veluzi, citing Veluz’s contributions to Philippine mammal studies and conservation.

The study, titled “Three new species of Philippine forest mice (Apomys, Muridae, Mammalia), members of a clade endemic to Mindoro Island,” calls for protecting these unique ecosystems.

Photo: courtesy of researchgate.net