“Rediscovered” Volcano Mouse Survived the Second Most Powerful Eruption of the 20th Century

On June 15, 1991, after 500 years of dormancy, Mount Pinatubo erupted – the second most powerful terrestrial volcanic eruption of the 20th century. Despite evacuations inthe previous day, 847 people reported dead. The volcano on the Philippine island of Luzon spread to lava and ash approximately the Zambales Mountains, where the pools were up to 183 meters (600 feet) thick.

The eruption was so powerful that it reduced the height of Mount Pinatubo to 250 meters (820 feet), leaving space at the summit. The former greenery around the volcano, the old forests were severely damaged, or completely destroyed.

Twenty years after the incident, field archive researcher Danilo Balete conducted an expedition to Mount Pinatubo to survey mammals in the area. There was no survey of the area prior to the fire, but samples from the U.S. National Museum of Natural History set some records for the lowlands.

One species was of particular interest: the Apomys sacobianus, or the mouse of the Pinatubo volcano. The species discovered in 1956 at the bottom of a volcano on the banks of the Sacobia River. It feared that because of living on this volcano alone, the huge eruption wiped out the species from the face of the earth. This study, however, found that against all odds, volcanic mice are rich.

After Balete died in 2017, the paper completed by Eric Rickart, curator of the mammal Negaunee at the Chicago Field Museum and curator of the Vertebrates Museum of Natural History in Utah. It published this year in the Philippine Journal of Science. Rickart said in a statement, “Danny didn’t get a chance to see how the mammals were training on the Mt. Pinatubo.” Heaney said,”The best respect we can imagine for Danny is knowing the species that once seemed a weakness, and even threatened to become extinct.”

The surveyed locations in the eastern slope of the hill were between 200 and 1,100 meters (656 and 3,609 feet) high. These regions were selected locations with the help of indigenous flour people as their ancestral domain.

The researchers documented 17 mammal species in the region. They found eight species of bats, (three infectious and five fruit bats), seven small airless mammals (five native and two non-native rats) and two native large mammals (wild boar and deer). The Pinatubo volcano mouse was actually the most abundant of the native small mammals, with 226 captives. The mouse seemed to be more successfully tempted with earthworms than coconut bait.

Heaney said, “After the Pinatubo eruption, we searched for this mouse on other peaks in the Zambales Mountains but failed to discover it, suggesting a very limited geographical distribution for the species. We thought the volcano was the only place the mouse could live.” The authors of the paper believe that this species thrives in a habitat that is a “disruption expert”, severely disrupted.

Indeed, many of the native species seem to have miraculously produced good fruit in the face of extinction. Rickart explained, “For some time, we have known that many small mammals in the Philippines can tolerate habitat instability, both natural and human, but most of them are geographically diverse, not locally endangered species, and are generally seen as extremely vulnerable by conservation biologists.” “Mt. Pinatubo could be a great place to set up long-term projects to monitor habitat recovery and community reunification after the eruption. This kind of information will help in efforts to reproduce many areas that have been deforested by the public.”