Luzon has the greatest concentration of unique mammal species in the whole world

  • Luzon has the most number of unique mammal species in the whole world
  • Up to 52 species of mammals can be found only in Luzon and nowhere else in the world
  • However, only 7 percent of Luzon’s original forest land remains

The island of Luzon, which is the largest among the more than 7,000 islands in the Philippines, has the highest concentration of unique mammal species in the whole world.

A study by a team of researchers from the Field Museum in Chicago, which spanned 15 years, revealed that Luzon is home to a number of mammals that can be found in no other places in the planet.

“We started our study on Luzon in 2000 because we knew at the time that most of the native mammal species on the island were unique to the island, and we wanted to understand why that is the case. We did not expect that we would double the number already known,” project leader Lawrence Heaney told Phys.

At least 52 non-flying mammal species are unique only to the island, including 28 new species that were discovered during the course of the field research.

Among the creatures endemic only to Luzon are four species of tree mice, five species of shrew-like mice, and some species of cloud rats.

The island is also host to 57 species of bats, including the golden-crowned flying fox which is considered to be among the largest in the whole world.

“All 28 of the species we discovered during the project are members of two branches on the tree of life that are confined to the Philippines. There are individual mountains on Luzon that have five species of mammals that live nowhere else. That’s more unique species on one mountain than live in any country in continental Europe. The concentration of unique biodiversity in the Philippines is really staggering,” Eric Rickart, another member of the team, explained.

Among the possible reasons for the huge biodiversity of Luzon is the fact that the island was never connected to the mainland continent which isolated many of the species living away from predators or competitors, eventually developing special adaptations and forming new species.

In addition, the mountains of Luzon also further isolated a number of these mammals, which further widened the extent of the biodiversity in the island.

“The animals are isolated high on the scattered mountains, so they inevitably diverge. Given enough time, you begin to see huge biodiversity. In the process of trying to understand how that happens, we doubled the number of known species on Luzon,” Heaney said.

While the huge number of mammal species can be a cause for celebration, conservationists warn that many of these unique creatures are under threat.

Luzon also happens to be the most populated island of the Philippines and is among the most heavily deforested areas in the world. Only 7 percent of the island’s original forest is left.

“Protecting all of these species from extinction is going to be a big challenge,” said Filipino team member Danny Balete.