Philippine eagle

Name and taxonomy

The English explorer John Whitehead watched the bird in 1896. A servant named Juan shot the first specimen for him a few weeks later. William Robert Ogilvie-Grant received the skin in London and named the species that year. He first showed it off in a restaurant near his home. The genus name joins the Greek words for ape and eater. The species name honours Jeffery Whitehead, the father of John.

People on Samar told the collectors that the bird ate only monkeys. That report gave the species its first English name. Later work showed a far wider diet, so the name was dropped. A proclamation of 1978 made Philippine eagle the official name. Filipino languages call it banoy, agila, manaul, tipule and mam-boogook. Modern Filipino uses haribon, which packs two words meaning bird king.

Evolution and relatives

The species is the only member of its genus, and it has no subspecies. A study of its skeleton in 1919 put the harpy eagle closest to it. Books then filed it with the harpy eagles in the subfamily Harpiinae. DNA work in 2005 broke that link. The nearest relatives turned out to be the snake eagles, a group that includes the bateleur. The species now sits in the subfamily Circaetinae.

The eagle appears to stand almost alone on the tree of living birds. The Zoological Society of London ranks it in the top 15 of its EDGE list. That list scores a species on how distinct it is and how close to extinction. It is the most distinct and most endangered animal in the Philippines by that measure. Island life without rival predators probably shaped the bird into the top hunter of the forest.

Appearance

The face is dark, and the crown and nape are a creamy brown. Long feathers on the nape lift into a mane-like crest. The back is dark brown, and the underside and underwings are white. The legs are heavy and yellow, and the claws are dark and thick. The tall arched bill is bluish grey, and the eyes are blue-grey. A juvenile looks the same but for pale edges on the upper feathers.

The reported length runs from 86 to 102 centimetres. The longest bird on record measured 112 cm, though it had lived in captivity. The wings are broad but shorter than those of eagles that hunt open country. The lower leg is 12.2 to 14.5 cm long, which ties the longest of any eagle. The bill averages 7.22 cm from the gape. The tail is long as well, at 42 to 45.3 cm.

Habitat and range

The species lives only in the Philippines. It survives on eastern Luzon, Samar, Leyte and Mindanao. Mindanao holds the bulk of the birds, with 82 to 233 breeding pairs. Samar holds about six pairs, Leyte two, and Luzon a few more. National parks on Mount Apo, Mount Kitanglad and Mount Malindang protect some of them. The Northern Sierra Madre National Park holds the Luzon birds.

The eagle wants dipterocarp forest and mid-montane forest, often on steep ground. It ranges from the lowlands up past 1,800 metres. Its total range covers about 146,000 square kilometres. Only about 9,220 square kilometres of old-growth forest are left inside that range. The gap between those two figures is probably the whole conservation problem.

Diet and hunting

This eagle takes whatever the forest offers in numbers. Flying lemurs form up to 90 percent of the food at some Mindanao sites. Luzon has no flying lemurs, so birds there hunt macaques, reptiles and giant cloud rats. A northern Luzon cloud rat weighs 2 to 2.5 kilograms. Civets, flying squirrels, flying foxes, rats and mouse deer fill in the rest. Prey at nests has ranged from a 10 gram bat to a 14 kg Philippine deer.

The eagle also takes hornbills, owls, hawks, snakes and monitor lizards. One pair even carried a Philippine cobra to the nest. Near villages the birds catch chickens, cats, piglets and small dogs. One hunting method is to sit still near the canopy and watch. The other is to glide from perch to perch, working down the branches and back up. A pair may hunt monkeys together, with one bird distracting the troop.

Behaviour and social life

The bird flaps far more than it soars, and its flight is fast and agile. It seems to behave more like a large forest hawk than like an open-country eagle. It is active by day, does not migrate and lives alone or with its mate. A pair needs a very large area to raise one chick. Home ranges of 60 to 130 square kilometres have been reported.

On Mindanao the nearest breeding pairs sat about 13 kilometres apart. That spacing gives each pair a circle of roughly 133 square kilometres. Young birds play, and the play appears to be practice for hunting. They grip knotholes, push their heads into tree cavities and balance with tail and wings. They also attack objects and hang upside down while the parents are away.

Communication and senses

Calls appear to carry most of the message in this species. A bird calls to its mate, and it calls most in the breeding season. A fledgling and its parents keep contact by voice. Loud advertisement calls go with the display flights of courtship. The calls seem to tell neighbours that a territory is taken.

Display seems to carry the rest of the message. A pair soars together over the nesting ground. The male chases the female in a slanting dive. He shows his talons at her back, and she rolls over to show her own. Like other eagles, it hunts by sight and can spot a small animal in the canopy.

Reproduction and life cycle

The full breeding cycle takes two years. A female is ready to breed at five years old and a male at seven. Pairs stay together for life, and a widowed bird usually finds a new mate. Courtship starts when a bird begins to build and stays near the nest. The earliest courtship on record fell in July.

The nest goes in a tall dipterocarp or another tree with an open crown. It is a platform of sticks about 1.5 metres across, lined with green leaves. It usually sits 30 metres or more above the ground. A pair uses the same nest for one chick after another. Eight to 10 days before laying, the female stops eating and drinks a great deal. Keepers call that state egg lethargy.

She lays a single egg, usually in the late afternoon or at dusk. Both parents incubate, and the female sits through every night. The egg hatches after 58 to 68 days, and 62 days is typical. The chick becomes independent at about five months. Wild birds are thought to live 30 to 60 years. One captive bird at the Philippine Eagle Center reached 46 years.

Predators and threats

No wild animal hunts a grown Philippine eagle. People are, in general, the whole of the problem. Five eagles were shot on Mindanao between 1999 and 2000. Three were trapped in the Sierra Madre of Luzon between 2002 and 2003. Of four tagged young birds followed from 1998 to 2002, three were lost to hunting and trapping.

More than 20 eagles have been rescued since 2019, most of them with gunshot wounds. Birds also die in snares that villagers set for deer. A released bird named Kabayan was electrocuted in January 2005. Another named Kagsabua was released in 2008, and a farmer shot and ate it. Logging, mining, pesticides and floods after clearance add to the pressure. Typhoon Haiyan wrecked the forest of Leyte in 2013, and nobody saw an eagle there afterwards. Two rescued birds were flown to Leyte in June 2024 to start the island again. The male drowned at sea, and the female was still hunting well in October 2024.

Population and conservation

The IUCN and BirdLife International listed the species as Critically Endangered in 1994. The IUCN then put the survivors at 180 to 500 birds. A 2015 estimate raised the figure to about 600. The Philippine Eagle Foundation counts about 400 pairs in the wild. Loss of old-growth forest remains the first cause of the decline.

Dioscoro Rabor and Jesus Alvarez raised the alarm abroad in 1965. Charles Lindbergh visited the country several times between 1969 and 1972 for the World Wildlife Fund. His visits helped move the government towards protection. A conservation programme began in 1969. The first captive hatching came in 1992 and the first natural one in 1999. The foundation in Davao City has bred the eagle 31 times as of 2025.

Relationship with humans

President Fidel Ramos declared the bird the national bird on 4 July 1995. Killing one carries up to 12 years in prison and heavy fines. The eagle appears on the 1,000-peso banknote, which caused an argument when the design changed. It has been on at least 12 stamps and on the 50-sentimo coin. It served as the mascot Gilas at the 2005 Southeast Asian Games.

The country now lends eagles abroad as a form of diplomacy. A male named Geothermica and a female named Sambisig went to Singapore in 2019. Each bird travelled with a printed passport of its own. Geothermica died of a fungal infection in 2022, and Sambisig stayed on. Birdwatchers travel to Mindanao to see the species, which probably brings work to local guides.

In culture and myth

Visayan tradition knows a great bird called Manaul. The name belongs to this eagle and to the white-bellied sea eagle. In the creation story only the sea, the sky and Manaul existed at first. The bird grew tired of flying and could find nowhere to rest. So it set the sky god Kaptan against the sea goddess Magwayen.

Kaptan sent storms down and Magwayen sent waves up. The long fight between them raised dry land out of the water. Manaul then dropped boulders to part the wind from the waves. Those boulders became the islands of the Philippines. Another story has Manaul peck a bamboo stem open to free the first man and woman.

Tagalog tradition gives both stories to Amihan, the spirit of the northeast wind. Amihan also takes the shape of a bird. The modern name haribon appears to carry the same idea of a royal bird. The national basketball team wears the eagle on its crest.