The Great Philippine Eagle

Patrick Dunn

  Patrick Dunn is the co-owner of Ave Azul de la Osa, located in Aguas Buenas, Osa.  You may reach him at


Between true eagles, fish eagles, snake eagles, serpent eagles and hawk eagles there are 72 genera alone and 280 species split between the Falconiformes (hawks) and Accipitridae (eagles) orders.  Of all these raptors, one taxon stands clearly out:  the harpy group.  Only two species are known and they could not farther apart, at least geographically. One is native to New Guinea, the other our New World harpy about which many of us here on the Osa have either seen or heard tales.  But the subject of today’s Birder’s Corner is not a harpy itself but a closely related species, the only one in the raptor family that occurs in its sole genus.  The Great Philippine Eagle, formerly known as the Monkey-eating Eagle, is also called the flying wolf.  Pithecophanga jefferyi is an avian powerhouse with an ancestral range including all of the the Philippine’s more than 7,000 islands.  In current times, however, the bird is confined in small numbers to just four islands:  Leyte, Samar, Luzon and Mindanao. The surviving number of birds hovers around 100 specimens. Fifty years ago there were more than 200 known to exist.

3004090218_aguila_filipina_77Weighing in at about 10 pounds (4.7 kg) a large female may tip the scales at about 15 lbs whereas a large female harpy eagle can weigh as much as 20 lbs.  Males of the two species are about the same weight.  Both species are magnificent crested birds with head and facial disks for gathering sound; the Philippine sports a spiky feather head dress reminiscent of some ancient warrior whereas the harpy eagle has feathers that fan upwards around its head.

The Philippine eagle was first collected and described by John Whitehead in 1896.  An inhabitant of tropical forests and what is left of them in the southeast Asian archipelago, the group the bird has always been in high demand as a hunter’s trophy. Many Philippine hunters aspired to have one mounted in their homes or chained up outdoors. The birds’ fate was sealed after the First World War, when firearms became widely available to locals and the species was decimated. It has been further reduced by destruction of habitat and is often shot by loggers.  Coupled with a rocketing human population and wasteful agricultural methods in its native Philippines, the bird is now teetering on the edge of extinction. Remnant populations are now the subject of a captive breeding program that seeks better protection in the wild and to restore captives possessed by locals through amnesty and conversion to captive breeding programs.  Ideally the species can in this way be restored to its natural environment while some birds remain in captivity to continue breeding programs. But this magnificent bird may never again become abundant since too much habitat has been lost already.  Pairs require an area of some 5 square miles for reproduction.  The Despite passage of local and international CITES legislation protecting the Philippine eagle, it  is now acutely threatened with extinction.


The Great Philippine Eagle subsists mainly on primates, but its diet includes other birds and animals, including flying lemurs, palm civets, flying squirrels, hornbills, mouse deer up to 30 lbs, and pythons.  With eyesight eight times more acute than that of humans the bird can spot its own mate from a mile away.  The Philippine eagle breeds naturally under ideal and undisturbed conditions once per year.  The Harpy, on the other hand breeds only once every 2 years at the most frequent.  As might be expected the eggs of both species have long incubation periods of around 60 days, about twice as long as a macaw egg.  It takes 120 days for a chick to fully fledge the nest, and juveniles remain close to its parents for up to two years. Some individuals may actually skip the next breeding cycle to ensure the last chick completely fledges.  Unsurprisingly, they favor the tallest trees in the forest for nesting, up to and over 150ft.  In the late 1990’s there were only four active nests known and no documented babies recorded.

In 1990 an effort was made to increase numbers of the species by creating a captive breeding facility.  Named the “Philippine Eagle Foundation,” or PEFI, it is located on the isle of Mindanao in the city of Malagos. Highly competent and dedicated experts are attempting to save the species from extinction before it is too late.  Since 2001 only two chicks have hatched at the facility. They are, however, the world’s first captive breeding for the species and a nucleus for a hopeful future. Though I have not visited the facility, which is not open to the public, I have heard from associates that it is top notch with an advanced veterinary hospital and incubation facility. Additionally, there are units located on immaculate grounds for researchers and spacious aviaries up to 50 ft. high.  The center is directed by veterinarian Dr. Roberto P. Puentespina and curator of operations Domingo Tadena, who are responsible for the breeding programs at the center. In 1996 there were 17 Eagles at the center. It has taken many years to understand the breeding biology of this bird and it appears they are making headway. Being creatures of habit they do not accept change well so a regimented daily routine is critical.

In 1975 there were but five individuals in zoos throughout the world.  Among those, the zoos of Antwerp, Frankfurt, Los Angles and Tokyo each attempted captive breeding programs but failed. Although intentions were sincere, not enough was known at the time to successfully breed the birds species in captivity. There is one exceptional record of an example which lived 41 years and 7 months at the Rome zoo having arrived there in December of 1934 and expired in July, 1976.

Like many species these days the survival of this bird may lie in aviculture and captive breeding. The ultimate goal is to protect enough primordial habitat to support a wild population.  If this can be achieved, increased numbers of the species in captive-breeding programs may be able to stock that habitat to restore the bird to some of its former range and in that way save and bring back the Philippines’ national bird.

Only time will tell, and I—for one—am am watching closely.


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