“They are looking for thermal air currents which can be found in Latian Complex. Mount Gulo which is located in Latian Complex can be the possible roosting site of such raptors,” ECPC executive director Atty. Emma Nebran explained.
Mt. Latian Complex has been identified as one of the important biodiversity areas in the Philippines. In 2002, it was declared by the Department of Environment and Natural Resources as Philippine Biodiversity Conservation priority.
The presence of migratory birds in Glan was first noticed in 2014; and again in March this year.
“Some residents in Barangay Cross have noticed a thick flock of birds covering the sun, flying together,” said Nebran.
Some of the birds were also seen in Barangay New Aklan. “If they will be here, we would not be surprised because we prepared ahead of time,” said New Aklan Barangay Captain Victorio Salutan.
Servita said the migration of the raptors is particularly sensitive indicator of environmental health which would draw the interest of tourists and wildlife enthusiasts.
Hence, conducting long-term counts of migrating raptors can help in the study of their migration patterns, behaviors and populations.
Reconnaissance of the best bird-watching site has been done by ECPC. So far, Barangay Laguimit would be the best site to watch them.
The birds arrive here twice a year; September to October and March to April.
Nebran explained that in spots where the ground is warm, the air rises, forming thermal currents. Raptors find these thermals and spiral upward without having to flap their wings.
It helps them travel long distances without using much energy. Raptors stick to the mountains because of thermals.
These birds are characterized by their sharp vision that allows them to detect prey during flight. This type of birds usually feed on rats and insects. Thus they serve as natural pest control in the area.
"They are not really monitored in our country. But studies and in-depth monitoring were done in Indonesia and Taiwan," said Servita. "One theory states that Sarangani might be their exit point going to Indonesia and could be the major flyway."
ECPC, the TWG and WBCP will conduct the month-long study which aims to promote coordinated actions to achieve and maintain the favorable conservation status of migratory raptors; to protect these migratory species along their flyways and to identify their important habitats, roosting sites and favored routes; and to produce a relevant research.
An earlier study, “Project Southern Crossing 2014: first observations of autumn raptor migration at Sarangani, Mindanao, Philippines”, by authors Alex M. Tiongco, Maria Teresa A. Cervero, Adrian M. Constantino and Maria Katrina C. Constantino described the Philippines as an “important link in the East Asia–Australasian Flyway (BirdLife International 2015), a migration route involving long sea crossings.”
According to the study, in autumn and spring, thousands of raptors pass through the Philippines; some are believed to winter in the country.
“In autumn, the birds fly south from the Palearctic breeding areas, passing across south-east China and Taiwan before arriving on Luzon en route to wintering areas further south.”
The WBCP Raptor Study Group (RSG) has made exploratory expeditions to map the migratory routes through the country, including entry and exit points.
“During the 2014 autumn migration, the RSG decided to work in the Davao del Sur and Sarangani area,” the study said.
“Initial observations at Cross revealed a passage of migrants from Mt. Gulo and nearby roosting areas with the vantage
point directly below the migration path,” it added.
“In all, nine raptor species were seen during the watch, six migrants and three residents. The migrant species seen were (Western) Osprey Pandion haliaetus (8), Crested Honey Buzzard
Pernis ptilorynchus (14), Chinese Sparrowhawk Accipiter soloensis (47,307), Japanese Sparrowhawk A. gularis (2), Grey-faced Buzzard Butastur indicus (242) and Peregrine Falcon Falco peregrinus (2). Resident species observed were Philippine Serpent Eagle Spilornis holospilus (5), South Philippine (Pinsker’s) Hawk-eagle Nisaetus pinskeri (28) and Brahminy Kite Haliastur Indus (60). Unidentified falcons (4) and other raptors (6) were also observed.”
Chinese Sparrowhawk was the predominant species, comprising 99% of the raptors observed.
The study suggested that Sarangani “is very likely to be a major migration route in autumn for raptors crossing from the Philippines to Sulawesi.” (Cherry Marie Irish D. Cruz and Serafin N. Ramos Jr. /SARANGANI INFORMATION OFFICE)