A Filipino fruit dove reveals its secrets

In May 1953, Filipino ornithologist DS Rabor collected a single female dove from the forested slopes of an active volcano on the Philippine island of Negros. The small apple-green bird, which had yellow borders on its wings and prominent circles of bare skin around its eyes, was unlike any other known species of pigeon. In 1954, Professor Dillon Ripley of Rabor and Yale described the unique specimen as Ptilinopus arcanus, a name inspired by the Latin word meaning “secret.”

The Negros Fruit Dove, as it is commonly known, has never been seen or recorded and remains one of the most enigmatic and misunderstood birds in the world. In the absence of new information, ornithologists have speculated that the bird may be an aberrant individual or a hybrid of two other well-known species.

Today, after more than 70 years, this unique specimen finally reveals its secrets.

Using DNA sequencing techniques, a team of Yale biologists, led by John Nash, a senior at Yale College, demonstrated that the Negros fruit dove is an ancient and highly distinct lineage within the evolutionary radiation from doves to Ptilinopus fruits. This species diverged from other fruit doves in this group almost 12 million years ago, long before Negros Island emerged from the seafloor. This suggests that Arcanus enjoyed a much wider distribution earlier in its evolutionary history, the researchers say.

Their findings are published in Ibis.

“When I arrived at Yale 20 years ago, we dreamed of solving the mystery of this unique bird,” said co-author Richard Prum, the William Robertson Coe Professor of Ornithology Ecology and Evolutionary Biology at the Yale Faculty of Arts and Sciences. “But we had to wait for the right technology and the right student to really succeed.”

To help guide future efforts to potentially relocate and conserve the species, which may still exist in the wild, the authors also modeled the biogeographic history of montane (or montane) and lowland forests, where it is more likely to be found, during the period. Pleistocene epoch, period marked by dramatic climate change. They argue that the only known fact about the Negros fruit dove – its presence on Negros – is more consistent with the biogeographic pattern of montane species in this region.

As a result, they identified several little-explored locations, including the montane forests of North Negros National Park and on the neighboring island of Panay, as areas that should be urgently surveyed for any surviving members of this species.

Nash, who studies ecology and evolutionary biology at Yale, thinks this enigmatic species may have even more secrets to reveal.

“After studying its genetics and phylogeny in the laboratory, I would like to lead the effort to rediscover it in the wild,” he said.