Every year, towards the start of autumn in the Northern Hemisphere, hundreds of thousands of raptors fly from Russia and Asia toward warmer climes in the south—only to vanish from sight when they reach the Philippines.
Come spring, those raptors that miraculously survived the journey south make the perilous return back north. As many as three in ten don't make it back to their breeding grounds in the summer, according to experts: many perish from the innumerable hazards of long-range migration, including hunting and destruction of foraging areas in their wintering grounds.
Just how many survived or died while in the Philippines, nobody knows.
Experts track the birds' seasonal movements in an effort to collect data that could be useful for conservation. But the problem is that the trail grows cold when they enter Philippine airspace: no one knows exactly where in the country the birds go.
Raptors' known migration patterns. Note the lack of route information in the Philippines (see map below).
A 'black hole' for raptors
Because of these mysteries, the country has been described as a "black hole" of raptor information in the region, according to the Wild Bird Club of the Philippines (WBCP) Raptor Study Group's Alex Tiongco.
It is this gap that the group of volunteers, led by Tiongco and Tere Cervero, are hoping to fill.
Just to illustrate the depth of this mystery: in autumn 2007, a team of researchers led by Francesco Germi on Indonesia's Sangihe Island counted 230,214 raptors flying south, coming from the general direction of Mindanao.
But no one on our end was looking. And even if someone were on watch, he might have not been looking in the right place because no one has bothered to map the Philippines' raptor migration routes.
The Asian Raptor Research and Conservation Network (ARRCN) says that as many as 14 different species of migrant raptors have been spotted in the Philippines. The most recent data suggest that the bulk of these are the Grey-faced Buzzard (Butastur indicus) and the Chinese Sparrowhawk (Accipiter soloensis).
Other migrants sighted in the country include the Crested Honey Buzzard (Pernis ptilorhyncus), the Japanese Sparrowhawk (Accipiter gularis), the Eastern Marsh Harrier (Circus spilonotus), the Pied Harrier (Circus melanoleucus), and the Common Kestrel (Falco tinnunculus).
A lack of resources, the complicated geography of the Philippines, and a host of other factors have hindered researchers' attempts to mount a coordinated effort to chart raptors' flyways.
In 2007 alone, an estimated 230,000 raptors—mostly Chinese Sparrowhawks, like this one—were spotted by an Indonesian observer, likely en route to the Philippines. Nobody knows where they went while in the country.
Why study raptors? Conservation and tourism
"Raptors are important indicators of the status of the environment. Since they are on top of the food chain, they are sensitive to the changes in the ecosystem, as well as vulnerable to pollutants in the environment," said Tiongco.
In addition, raptors are good for farm communities because they feed on agricultural pests. Without natural predators, pests can multiply very quickly and decimate crops, Tiongco added.
"When we conserve and protect raptors, we also help conserve our natural habitats and resources, and maintain a stable and sustainable environment, which is essential for survival of both wildlife and humans," he said.
"By knowing the raptor flyways in the Philippines, we can gather more information about the habitats in these flyway zones and be able to think of conservation strategies in these areas, in collaboration with the local communities," he added.
Aside from its conservation potential, mapping the Philippine flyways could also boost ecotourism through development of tourism-oriented raptor-research facilities and programs similar to those in Chumphon, Thailand; Tanjung Tuan, Malaysia, and Kenting, Taiwan.
Such facilities bring ecotourism-related revenue to rural communities, provide a learning experience to students and create an infrastructure that could boost research on other wildlife species, Cervero said.
With the help of local volunteers, the group is considering establishing a regular monitoring site in Pagudpud, Ilocos Norte, which could be a major exit point for raptors flying northward. In the south, Cape San Agustin, Davao Oriental, and Sarangani Province show signs of being major exit points for raptors on southward migration, Tiongco said.
The majestic Grey-faced Buzzard (Butastur indicus) is just one of 14 species of raptors known to make their way across the Philippines in as-yet-unmapped migration routes.
Volunteer mapping efforts
The Raptor Study Group has embarked on an extensive mapping project, learning mostly through direct observation and trial-and-error, as well as by investigating eyewitness reports and seeking the advice of experts in neighboring countries.
The group receives occasional funding support from the WBCP and the ARRCN, and organizational backing from PAGASA, the Department of Environment and Natural Resources and local government units, but not much else. In Palawan, the group was assisted by the Katala Foundation, and in Rizal by the Alalay Sa Pamilya At Bayan Foundation.
Mostly, the volunteers spend their own money to further the research. To date, Tiongco and Cervero, who both have day jobs, have invested close to a million pesos of their own money to keep the project moving. This amount includes expenses for expeditions to northern Luzon, southern Palawan and southern Mindanao, and for trips to other countries in the East Asian Australasian Flyway to learn raptor identification and survey methods.
"This is a very costly project," Cervero says, shaking her head.
There are also the dangers of field research to contend with. In 2012, one of the volunteers was shot at by a possibly mentally disturbed individual in Rizal. Another time, volunteers had to abandon a monitoring site in southern Palawan after authorities warned them that armed insurgents could be headed in their direction.
To ease the challenges on themselves, the group is considering training school-based volunteers in northern Luzon, and perhaps in other places, to perform the seasonal monitoring, but negotiating with schools also takes time and money.
The Wild Bird Club of the Philippines–Raptor Study Group on the lookout at the PAGASA tower in Tanay, Rizal.
In 2013, the ARRCN sponsored a seminar in Quezon City featuring experts from Japan, as well as Malaysian Borneo, Indonesia, Taiwan and Mongolia, who shared their own experiences and challenges in studying raptors.
"The routes of these birds take them across political boundaries of countries so international cooperation is important for their conservation," Tiongco said.
The Raptor Study Group is looking forward to scheduling a similar seminar for student-volunteers in Sanchez Mira, Cagayan, which the group believes could also be an important staging area for raptors on northward migration.
The ARRCN is also aiming to hold its bi-annual raptor conference in 2017 in the Philippines, Tiongco said. By then, the Raptor Study Group should have shed some light on the mystery of raptor flyways in the country.
Tiongco, Cervero and their recruited volunteers are committed, despite the challenges, to continuing the research because of its importance to conservation.
"We have chalked up about a hundred thousand miles in pursuit of these raptors and to find out their flyways in the country, but those are very exciting miles," Cervero said. — TJD, GMA News
Mads Bajarias and Lu-ann Fuentes are founding members of the Wild Bird Club of the Philippines, a nonprofit group that seeks to protect Philippine birds and their habitats. The club can also be found on Facebook. The opinions expressed in this contributed article are those of the authors and do not necessarily reflect the views of GMA News Online.