Davao group gets new insights about Philippine eagle behavior

Feb. 28, 2023
A Mount Apo Philippine Eagle with its solar powered GPS tracker harnessed on its back. (Photo courtesy of Philippine Eagle Foundation)

DAVAO CITY, Philippines – The iconic national bird, the Philippine eagle, is on the brink of extinction.

Also known as the monkey-eating eagle (Pithecophaga jefferyi), it is one of the world’s most endangered forest eagles due to human activities like hunting and deforestation.

Despite being declared critically endangered by the International Union for Conservation of Nature (IUCN) more than 25 years ago, little has been done to protect these majestic creatures in the lush forests of the Philippines.

Using innovative technology, the Davao City-based Philippine Eagle Foundation (PEF), which partnered with Peregrine Fund and University of the Philippines-Mindanao, has gained a deeper understanding of eagle movement patterns in the wild.

Its paper has also shed light on the dire situation of the Philippine eagle and the need for better conservation efforts.

The paper, Priority Conservation Areas and a Global Population Estimate for the Critically Endangered Philippine Eagle, which was published in Animal Conservation this February, showed that there was a dearth of scientific knowledge necessary for making effective conservation decisions.

“Despite being one of the most endangered forest eagles in the world, we still lack fundamental information regarding the Philippine eagle distribution and population size,” said Dennis Salvador, PEF executive director and co-author of the paper.

The research employed technology, such as the use of satellite telemetry techniques, to gain a better understanding of the eagles’ behavior in the forests.

“With the use of satellite telemetry techniques like GPS trackers on nesting eagles using backpack harnesses, we know and understand better eagle movement patterns and how they use the forests in the wild,” the Foundation said.

The study found that the Philippine eagle prefers areas with 70-80% forest cover as habitat and avoids areas with thick or closed canopies.

They tolerate areas of low human impact or scattered small villages in between forests than areas with high-impact infrastructure.

The research also presents an updated approach to estimating conservation range metrics and population size, based on modeling highly suitable eagle habitat.

The Species Distribution Model approach approximated 2,862,400 hectares of forest to be suitable for the eagle, equivalent to 10% of the total land area of the Philippine archipelago.

The amount of suitable habitat could support around 392 Philippine eagle pairs, or a range of 318-447 pairs.

The paper identified priority eagle habitats from Luzon to Mindanao, with only 32% of the 45% minimum standard target coverage being covered by the Philippine protected area network.

The priority eagle habitats are Mount Kampalili Puting Bato, Mount Hilong-hilong, Mount Latian Complex, Mount Busa-Kiamba, Mount Piagayungan, Butig Mountains, Munai/Tambo in East Central Mindanao, Kaluayan-Kinabalian Complex (Pantaron ranges) along with Mount Balatukan and Mount Tago range in Mindanao.

The Anonang-Lobi Range in Leyte province and Mount Nacolod in Southern Leyte are the priority eagle habitats in the Visayas.

For Northern Luzon, the Apayao Lowland Forest and Balbalasang-Balbalan mountains were identified as highly suitable habitats.

Potential reintroductions or upgraded protection could be applicable for the Zambales mountains.

With these, the PEF can re-program and prioritize actions by systematically finding as many of the 392 territorial nesting pairs across the country, protecting threatened eagle nest sites, and ensuring the reproductive success and survival of each adult pair and their young through telemetry and field monitoring.

“Understanding how species are distributed and a reliable estimate of population size are key biological parameters for any threatened species,” said Luke Sutton, a research fellow of the Peregrine Fund in Boise, Idaho, United States, and lead author of the paper.

Dr. Jayson Ibanez, the research director and co-author at PEF, suggested an approach to protect the 392 territorial nesting pairs of eagles across the country.

The approach involves conducting systematic nest surveys to locate these pairs, improving education outreach, wildlife law enforcement, and community-based conservation to protect the threatened eagle nest sites.

It also involves the monitoring of each adult pair and their young through telemetry and field monitoring to ensure their reproductive success and survival.

By prioritizing and implementing these actions, the program can be re-programmed towards better protection of the eagles.

Chris McClure, executive vice president of the Science and Conservation at the Peregrine Fund, another co-author of the paper, lauded the scientific and grassroots approach of PEF and its network of government, private and community collaborators, calling it an ideal model for national raptor conservation.

The team also included biologists Rowell Taraya and Tristan Senarillos, as well as GIS specialist Guiller Opiso from the PEF.

The Davao-based foundation is a non-governmental organization that has long been working to preserve the Philippine eagle and its rainforest habitat.

The group has been using a comprehensive approach that involves field research, protecting and restoring the forest, conserving indigenous cultures and upland communities, educating the public, and rehabilitating, conserving, and releasing eagles.

PEF is an active member of the Global Raptor Impact Network, a network and database for studying and conserving the world’s raptors convened by the Peregrine Fund. (originally posted on rappler.com)

Lucelle Bonzo is an Aries Rufo Journalism fellow.

comments powered by Disqus