It has brown and white-colored plumage, a shaggy crest, and generally measures 86 to 102 cm (2.82 to 3.35 ft) in length and weighs 4.04 to 8.0 kg (8.9 to 17.6 lb).

[7] Killing a Philippine eagle is a criminal offence, punishable by law with up to 12 years' imprisonment and heavy fines.

[5][9] The first European to study the species was the English explorer and naturalist John Whitehead in 1896, who observed the bird and whose servant, Juan, collected the first specimen a few weeks later.

[10] The skin of the bird was sent to William Robert Ogilvie-Grant in London in 1896, who initially showed it off in a local restaurant and described the species a few weeks later.

[12] These reports gave its generic name, from the Greek pithecus (πίθηκος, "ape" or "monkey") and phagus (-φάγος, "eater of").

[15] A 1919 study of the bird's skeletal features led to the suggestion that the nearest relative was the Harpy eagle (Harpia harpyja).

[16] The species was included in the subfamily Harpiinae until a 2005 study of DNA sequences which identified them as not members of the group, finding instead that the nearest relatives are Snake eagles (Circaetinae), such as the bateleur.

[17] The Philippine eagle's nape is adorned with long, brown feathers that form a shaggy, mane-like crest.

[28] The most frequently heard noises made by the Philippine eagle are loud, high-pitched whistles ending with inflections in pitch.

The Philippine eagle has a wide range of prey which includes birds, reptiles and mammals (mainly civets and colugos).

[31] Each breeding pair requires a large home range to successfully raise a chick, thus the species is extremely vulnerable to deforestation.

[37] The primary prey is usually the tree squirrel-sized Philippine flying lemurs, which can make up an estimated 90% of the raptor's diet in some locations.

[4] Reptiles occasionally form a large part of their diet, snakes such as Ptyas luzonensis and Gonyosoma oxycephalum are mainly taken.

[39] Venomous pit vipers (Viperidae) are also taken as prey, and in one instance, a breeding pair delivered a Philippine cobra (Naja philippinensis) to the nest.

Eagles in Mindanao often find success using the latter method while hunting flying lemurs, since they are nocturnal animals that try to use camouflage to protect themselves by day.

[4] Eagle pairs sometimes hunt troops of monkeys cooperatively, with one bird perching nearby to distract the primates, allowing the other to swoop in from behind, hopefully unnoticed, for the kill.

[10] The nest is normally built on an emergent dipterocarp, or any tall tree with an open crown, in primary or disturbed forest.

[34] Both parents take care of the eaglet for a total of 20 months and, unless the previous nesting attempt had failed, the eagles can breed only in alternate years.

[10] The diminishing numbers of the Philippine eagle were first brought to international attention in 1965 by the noted Filipino ornithologist Dioscoro S. Rabor, and the director of the Parks and Wildlife Office, Jesus A.

As a representative of the World Wildlife Fund, Lindbergh traveled to the Philippines several times between 1969 and 1972, where he helped persuade the government to protect the eagle.

[44] Killing this critically endangered species is punishable under Philippine law by 12 years in jail and heavy fines.

They were released in hopes that they would form a pair but this project faced a significant setback when the male named "Uswag" was found dead at sea.

As of October 2024, the female named "Carlito" was documented alive and is hunting and able to fend for itself..[53][54][55] In a June 2019 wildlife loan agreement, a pair of Philippine eagles; (as of 2019) Geothermica, a 15 year old male and Sambisig (meaning one unity) a 17 year old female, were loaned to the Jurong Bird Park Singapore.

[58][59] As of 2024, Geothermica had died from lung infection, his body now taxidermied at the National Museum, while Sambisig remained in Singapore at the new bird park that replaced Jurong.

Despite this setback, Singapore Zoo and the Philippine Eagle Foundation maintain that this breeding program will continue and it will be likely that another possible mate for "Sambisig" will be loaned.

His sculpture stands in the center of the new facility while his taxidermied body is currently displayed at the National Museum of the Philippines.

The PEF partnered with Mandai Wildlife Group, United Architects of the Philippines-Davao City and Kublai Millan for the project.

[66] On December 11, 2021, the Bangko Sentral ng Pilipinas unveiled the design of the new 1,000-Piso polymer banknote featuring the bird as the main portrait, controversially replacing those of three World War II martyrs: Chief Justice José Abad Santos, suffragist Josefa Llanes Escoda, and General Vicente Lim.

Historically, about 50 Philippine eagles have been kept in zoos in Europe (England, Germany, Belgium, Italy and France), the United States, and Japan.

[10][69] The Philippine eagle is also used in sporting events as a mascot, most notably one in the 2005 Southeast Asian Games held in Manila known as "Gilas".