Philippine Eagle
Encyclopedia
The Philippine Eagle also known as the Monkey-eating Eagle, is an eagle of the family Accipitridae
that is endemic to forests in the Philippines
. It has brown and white-coloured plumage, and a shaggy crest, and generally measures 86–102 cm (2.8–3.3 ft) in length and weighs 4.7 to 8 kg (10.4 to 17.6 lb). Among the rarest, largest, and most powerful bird
s in the world, it has been declared the Philippines national bird. It is critically endangered
, mainly due to massive loss of habitat due to deforestation in most of its range. Killing a Philippine Eagle is punishable under Philippine law by twelve years in jail and heavy fines.
an to discover the species in 1896 was the English explorer and naturalist John Whitehead
, who observed the bird and whose servant, Juan, collected the first specimen a few weeks later. 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.
Upon its discovery, the Philippine Eagle was first called the monkey-eating eagle because of reports from natives of Bonga, Samar
, where the species was first discovered, that it preyed exclusively on monkeys; from these reports it gained its generic name
, from the Greek
pithecus ("ape or monkey") and phagus ("eater of"). The specific name commemorates Jeffery Whitehead, the father of John Whitehead
. Later studies revealed, however, that the alleged monkey-eating eagle also ate other animals such as colugo
, civet
s, large snake
s, monitor lizard
s, and even large birds like hornbill
s. This, coupled with the fact that the same name applied to the African Crowned Eagle
and the Central and South American Harpy Eagle, resulted in a presidential proclamation to change its name to Philippine Eagle in 1978, and in 1995 was declared a national emblem
. This species has no recognized subspecies
.
Apart from Philippine Eagle and Monkey-eating Eagle, it has also been called the Great Philippine Eagle. It has numerous local names, including agila ("eagle"), haribon, haring ibon ("bird king") and banog ("kite").
sequences which identified them as non-members of the group, finding instead, that the nearest relatives are snake eagles (Circaetinae) such as the Bateleur
. The species has subsequently been placed in the subfamily Circaetinae.
s that form a shaggy crest. These feathers give it the appearance of possessing a lion's mane, which in turn resembles the mythical griffin
. The eagle has a dark face and a creamy-brown nape and crown. The back of the Philippine Eagle is dark brown, while the underside and underwings are white. The heavy legs are yellow with large, powerful dark claw
s, and the prominent large, high-arched, deep beak
is a bluish-gray. The eagle's eyes are blue-gray. Juveniles are similar to adults except that their upperpart feathers have pale fringes.
The Philippine Eagle is typically reported as being 86–102 cm (2.8–3.3 ft) long, but a survey at several of the largest natural history collection in the world found that the average was 95 centimetres (3.1 ft) for males and 105 centimetres (3.4 ft) for females. Based on the latter measurements, this makes it the longest extant species of eagle, as the average for the female equals the maximum reported for the Harpy Eagle and Steller's Sea Eagle
. The longest Philippine Eagle reported anywhere is a specimen
of unknown sex at the Field Museum of Natural History
(FMNH) that is 112 centimetres (3.7 ft), but it had been kept in captivity and therefore may not represent the wild individuals due to differences in the food availability. The level of sexual dimorphism
in size is not certain, but it is believed that the male typically is about 10% smaller than the female and this is supported by the average length provided for males and females in one source. For adult Philippine Eagles, the complete weight range has been reported as 4.7 to 8 kg (10.4 to 17.6 lb), while others have found that the average was 4.5 kilograms (9.9 lb) for males and 6 kilograms (13.2 lb) for females. It has a wingspan of 184 to 202 cm (6 to 6.6 ft). The maximum reported weight is surpassed by two other eagles (the Harpy and Steller's Sea Eagle) and the wings are shorter than large eagles of open country (such as the Martial Eagle
, Wedge-tailed Eagle
and Steller's Sea Eagle), but are quite broad.
The most frequently heard noises made by the Philippine Eagle are loud, high-pitched whistles ending with inflections in pitch. Additionally, juveniles have been known to beg for food by a series of high-pitched calls.
and can be found on four major islands: eastern Luzon
, Samar
, Leyte
and Mindanao
. The largest number of eagle
s reside on Mindanao, with between 82 and 233 breeding pairs. Only six pairs are found on Samar, two on Leyte, and a few on Luzon. It can be found in Northern Sierra Madre National Park
on Luzon and Mount Apo
and Mount Kitanglad National Park
s on Mindanao.
This eagle is found in dipterocarp and mid-montane forests, particularly in steep areas. Its elevation ranges from the lowlands to mountains of over 1800 metres (5,905.5 ft). It is estimated that only 9220 square kilometres (2,278,309.6 acre) of old growth forest remain in the bird's range. However, its total estimated range is about 146000 square kilometres (56,370.9 sq mi).
. Earlier it has been estimated that the territory
is about 100 square kilometre, but a study on Mindanao Island found the nearest distance between breeding pairs to be about 13 kilometres (8.1 mi) on average, resulting in a circular plot of 133 square kilometre.
The species' flight is fast and agile, resembling the smaller hawks more than similar large birds of prey.
Juveniles in play behavior have been observed gripping knotholes in trees with their talons and, using its tail and wings for balance, inserting its head into a tree cavity. Additionally, they have been known to attack inanimate objects for practice as well as attempt to hang upside down to work on their balance. As the parents are not nearby when this occurs, it has been suggested that they do not play a role in teaching the juvenile to hunt.
Life expectancy for a wild eagle is estimated to be anywhere from 30 to 60 years. A captive Philippine Eagle lived for 41 years in Rome Zoo, and it was already adult when it arrived at the zoo. However, it is believed that wild birds on average live shorter lives than captive birds.
) exclusively; this has proven to be inaccurate. The primary prey varies from island to island depending on species availability, particularly in Luzon and Mindanao. This is due to the islands being in different faunal regions. For example, Philippine flying lemur
s, the preferred prey in Mindanao, are absent in Luzon. The primary prey for the eagles seen in Luzon are monkeys, birds, flying foxes
, giant cloud-rats Phloeomys pallidus
which can weigh twice as much as flying lemurs (that is, 2 to 2.5 kg), and reptiles such as large snakes and lizards. The eagles prefer flying lemurs and Asian Palm Civets, but they occasionally eat small mammals, birds (owl
s and hornbill
s), reptiles (snake
s and monitor lizard
s), and even other birds of prey. There have been reports of eagles capturing young pigs and small dogs. It is estimated that the flying lemur could make up 90% of the raptor's diet in some locations.
Eagle pairs sometimes hunt troops of monkey cooperatively, with one bird perching nearby to distract the primates allowing the other to swoop in unnoticed for the kill.
The complete breeding cycle of the Philippine Eagle lasts two years. The female matures sexually at five years of age and the male at seven. Like most eagles, the Philippine Eagle is monogamous. Once paired, a couple remains together for the rest of their lives. If one dies, the remaining eagle often searches for a new mate to replace the one lost.
The beginning of courtship is signaled by nest-building and the eagle remaining near its nest. Aerial displays also play a major role in the courtship. These displays include paired soaring over a nesting territory, the male chasing the female in a diagonal dive, and mutual talon presentation, where the male presents his talons to the female's back and she flips over in mid-air to present her own talons. Advertisement displays coupled with loud calling have also been reported. The willingness of an eagle to breed is displayed by the eagle bringing nesting materials to the bird's nest. Copulation follows and occurs repeatedly both on the nest and on nearby perches. The earliest courtship has been reported in July.
Breeding begins between September and February; birds on different islands, most notably Mindanao and Luzon, begin breeding at different ends of this range. The amount of rainfall and population of prey may also affect the breeding season. The nest is normally built on an emergent dipterocarp, or any tall tree with an open crown, in primary or disturbed forest and may be nearly 1.5 metres (4.9 ft) across and about 30 metres (98.4 ft) above the ground. The eagle's nest resembles a huge platform made of sticks. The eagle frequently reuses the same nesting site for several different chicks. Eight to ten days before the egg is ready to be laid, the female is afflicted with a condition known as egg lethargy. In this experience, the female does not eat, drinks lots of water, and holds its wings droopingly. The female typically lays one egg in the late afternoon or at dusk, although occasionally two have been reported. If an egg fails to hatch or the chick dies early, the parents will likely lay another egg the following year. Copulation may last a few days after the egg is laid to enable another egg to be laid should the first one fail. The egg is incubated for 58 to 68 days after being laid. Both sexes participate in the incubation, but the female does the majority of incubating during the day and all of it at night.
Both sexes help feed the newly hatched eaglet. Additionally, the parents have been observed taking turns shielding the eaglet from the sun and rain until it is seven weeks old. The young eaglet fledges after four or five months. The earliest an eagle has been observed making a kill is 304 days after hatching. Both parents take care of the eaglet for a total of twenty months.
.jpg)
In 2010, the IUCN and BirdLife International
listed this species as critically endangered
. The International Union for the Conservation of Nature believes that between 180 and 500 Philippine Eagles survive in the Philippines. They are threatened primarily by deforestation through logging and expanding agriculture. Old growth forest is being lost at a high rate, and most of the eagle's forest in the lowlands is owned by logging companies. Mining, pollution, exposure to pesticides that affect breeding, and poaching
are also major threats. Additionally, they are occasionally caught in traps laid by local people for deer. Though this is no longer a major problem, the eagle's numbers were also reduced by being captured for zoos.
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 then director of the Parks and Wildlife Office, Jesus A. Alvarez. Charles Lindbergh
, best known for crossing the Atlantic alone and without stopping in 1927, was fascinated by this eagle. 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. In 1969, the Monkey-eating Eagle Conservation Program was started to help preserve this species. In 1992, the first Philippine Eagles were born in captivity through artificial insemination
; however, it was not until 1999 that the first naturally bred eaglet hatched. The first captive-bred bird to be released in the wild, Kabayan, was released in 2004 on Mindanao; however, he was accidentally electrocuted in January 2005. Another eagle, Kagsabua, was released March 6, 2008, but was shot and eaten by a farmer. Killing this critically endangered species is punishable under Philippine law by twelve years in jail and heavy fines.
Its numbers have slowly dwindled over the decades to the current population of 180 to 500 eagles. A series of floods and mud slides, caused by deforestation, further devastated the remaining population. The Philippine Eagle may soon no longer be found in the wild, unless direct intervention is taken. The Philippine Eagle Foundation of Davao City
, Mindanao
is one organization dedicated to the protection and conservation of the Philippine Eagle and its forest habitat. The Philippine Eagle Foundation has successfully bred Philippine Eagles in captivity for over a decade and conducted the first experimental release of a captive-bred eagle to the wild. The foundation has 32 eagles at its center, of which 18 were bred in captivity. Ongoing research on behavior, ecology and population dynamics is also underway. In recent years protected lands have been established specifically for this species, such as the 700 square kilometres (172,973.6 acre) Cabuaya Forest and the 37.2 square kilometres (9,192.3 acre) Taft Forest Wildlife Sanctuary on Samar. However, a large proportion of the population is found on unprotected land.
under Proclamation No. 615. This eagle, because of its size and rarity, is also a highly desired bird for birdwatchers.
The Philippine Eagle has also featured on at least twelve stamps from the Philippines, with dates ranging from 1967 to 2007. It was also depicted on the 50 centavo coins minted from 1981 to 1994.
Historically, about 50 Philippine Eagles have been kept in zoo
s in Europe (England, Germany, Belgium
, Italy
and France), United States and Japan
. The first was a female that arrived in London Zoo
in August 1909 and died there in February 1910. The majority arrived in zoos between 1947 and 1965. The last outside the Philippines died in 1988 in the Antwerp Zoo
where it had lived since 1964 (except for a period at the Planckendael Zoo in Belgium). The first captive breeding was only achieved in 1992 at the facility of the Philippine Eagle Foundation in Davao City
, Mindanao, the Philippines, which has bred it several times since then.
Accipitridae
The Accipitridae, one of the two major families within the order Accipitriformes , are a family of small to large birds with strongly hooked bills and variable morphology based on diet. They feed on a range of prey items from insects to medium-sized mammals, with a number feeding on carrion and a...
that is endemic to forests in the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
. It has brown and white-coloured plumage, and a shaggy crest, and generally measures 86–102 cm (2.8–3.3 ft) in length and weighs 4.7 to 8 kg (10.4 to 17.6 lb). Among the rarest, largest, and most powerful bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s in the world, it has been declared the Philippines national bird. It is critically endangered
Critically endangered
Version 2010.3 of the IUCN Red List of Threatened Species identified 3744 Critically Endangered species, subspecies and varieties, stocks and subpopulations.Critically Endangered by kingdom:*1993 Animalia*2 Fungi*1745 Plantae*4 Protista-References:...
, mainly due to massive loss of habitat due to deforestation in most of its range. Killing a Philippine Eagle is punishable under Philippine law by twelve years in jail and heavy fines.
Taxonomy
The first EuropeEurope
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
an to discover the species in 1896 was the English explorer and naturalist John Whitehead
John Whitehead (explorer)
John Whitehead was an English explorer, naturalist and professional collector of bird specimens.Whitehead travelled in Malacca, North Borneo, Java, and Palawan between 1885 and 1888, where he collected a number of zoological specimens new to science, including Whitehead's Broadbill , writing up...
, who observed the bird and whose servant, Juan, collected the first specimen a few weeks later. The skin of the bird was sent to William Robert Ogilvie-Grant
William Robert Ogilvie-Grant
William Robert Ogilvie-Grant was a Scottish ornithologist.-Career:Ogilvie-Grant was educated at Cargilfield and Fettes College, Edinburgh, where he studied zoology and anatomy. In 1882 he became an Assistant at the Natural History Museum. He studied ichthyology under Albert C. L. G...
in London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
in 1896, who initially showed it off in a local restaurant and described the species a few weeks later.
Upon its discovery, the Philippine Eagle was first called the monkey-eating eagle because of reports from natives of Bonga, Samar
Samar
Samar, formerly and also known as Western Samar, is a province in the Philippines located in the Eastern Visayas region. Its capital is Catbalogan City and covers the western portion of Samar as well as several islands in the Samar Sea located to the west of the mainland...
, where the species was first discovered, that it preyed exclusively on monkeys; from these reports it gained its generic name
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
, from the Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
pithecus ("ape or monkey") and phagus ("eater of"). The specific name commemorates Jeffery Whitehead, the father of John Whitehead
John Whitehead (explorer)
John Whitehead was an English explorer, naturalist and professional collector of bird specimens.Whitehead travelled in Malacca, North Borneo, Java, and Palawan between 1885 and 1888, where he collected a number of zoological specimens new to science, including Whitehead's Broadbill , writing up...
. Later studies revealed, however, that the alleged monkey-eating eagle also ate other animals such as colugo
Colugo
Colugos are arboreal gliding mammals found in South-east Asia. There are just two extant species, which make up the entire family Cynocephalidae and order Dermoptera. They are the most capable of all gliding mammals, using flaps of extra skin between their legs to glide from higher to lower...
, civet
Civet
The family Viverridae is made up of around 30 species of medium-sized mammal, including all of the genets, the binturong, most of the civets, and the two African linsangs....
s, large snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
s, monitor lizard
Monitor lizard
Monitor lizards are usually large reptiles, although some can be as small as in length. They have long necks, powerful tails and claws, and well-developed limbs. Most species are terrestrial, but arboreal and semiaquatic monitors are also known...
s, and even large birds like hornbill
Hornbill
Hornbills are a family of bird found in tropical and subtropical Africa, Asia and Melanesia. They are characterized by a long, down-curved bill which is frequently brightly-colored and sometimes has a casque on the upper mandible. Both the common English and the scientific name of the family...
s. This, coupled with the fact that the same name applied to the African Crowned Eagle
Crowned Eagle
The Crowned Eagle or Crowned Hawk-eagle , is a very large, powerful, crested bird of prey found in sub-Saharan Africa; in Southern Africa it is restricted to suitable habitat in the eastern areas. It is the only extant member of the genus Stephanoaetus...
and the Central and South American Harpy Eagle, resulted in a presidential proclamation to change its name to Philippine Eagle in 1978, and in 1995 was declared a national emblem
National emblem
A national emblem symbolically represents a nation. Most national emblems originate in the natural world, such as animals or birds, but another object may serve. National emblems may appear on many things such as the national flag, coat of arms, or other patriotic materials...
. This species has no recognized subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
.
Apart from Philippine Eagle and Monkey-eating Eagle, it has also been called the Great Philippine Eagle. It has numerous local names, including agila ("eagle"), haribon, haring ibon ("bird king") and banog ("kite").
Evolutionary history
A study of the skeletal features in 1919 led to the suggestion that the nearest relative was the Harpy Eagle. The species was included in the subfamily Harpiinae until a 2005 study of DNADNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
sequences which identified them as non-members of the group, finding instead, that the nearest relatives are snake eagles (Circaetinae) such as the Bateleur
Bateleur
The Bateleur is a medium-sized eagle in the bird family Accipitridae which also includes many other diurnal raptors such as buzzards, kites and harriers...
. The species has subsequently been placed in the subfamily Circaetinae.
Description
The Philippine Eagle's nape is adorned with long brown featherFeather
Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds and some non-avian theropod dinosaurs. They are considered the most complex integumentary structures found in vertebrates, and indeed a premier example of a complex evolutionary novelty. They...
s that form a shaggy crest. These feathers give it the appearance of possessing a lion's mane, which in turn resembles the mythical griffin
Griffin
The griffin, griffon, or gryphon is a legendary creature with the body of a lion and the head and wings of an eagle...
. The eagle has a dark face and a creamy-brown nape and crown. The back of the Philippine Eagle is dark brown, while the underside and underwings are white. The heavy legs are yellow with large, powerful dark claw
Claw
A claw is a curved, pointed appendage, found at the end of a toe or finger in most mammals, birds, and some reptiles. However, the word "claw" is also often used in reference to an invertebrate. Somewhat similar fine hooked structures are found in arthropods such as beetles and spiders, at the end...
s, and the prominent large, high-arched, deep beak
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
is a bluish-gray. The eagle's eyes are blue-gray. Juveniles are similar to adults except that their upperpart feathers have pale fringes.
The Philippine Eagle is typically reported as being 86–102 cm (2.8–3.3 ft) long, but a survey at several of the largest natural history collection in the world found that the average was 95 centimetres (3.1 ft) for males and 105 centimetres (3.4 ft) for females. Based on the latter measurements, this makes it the longest extant species of eagle, as the average for the female equals the maximum reported for the Harpy Eagle and Steller's Sea Eagle
Steller's Sea Eagle
The Steller's Sea Eagle, Haliaeetus pelagicus, is a large bird of prey in the family Accipitridae. It lives in coastal northeastern Asia and mainly preys on fish. It is, on average, the heaviest eagle in the world, at about , but often lags behind the Harpy Eagle and Philippine Eagle in other...
. The longest Philippine Eagle reported anywhere is a specimen
Specimen
A specimen is a portion/quantity of material for use in testing, examination, or study.BiologyA laboratory specimen is an individual animal, part of an animal, a plant, part of a plant, or a microorganism, used as a representative to study the properties of the whole population of that species or...
of unknown sex at the Field Museum of Natural History
Field Museum of Natural History
The Field Museum of Natural History is located in Chicago, Illinois, USA. It sits on Lake Shore Drive next to Lake Michigan, part of a scenic complex known as the Museum Campus Chicago...
(FMNH) that is 112 centimetres (3.7 ft), but it had been kept in captivity and therefore may not represent the wild individuals due to differences in the food availability. The level of sexual dimorphism
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
in size is not certain, but it is believed that the male typically is about 10% smaller than the female and this is supported by the average length provided for males and females in one source. For adult Philippine Eagles, the complete weight range has been reported as 4.7 to 8 kg (10.4 to 17.6 lb), while others have found that the average was 4.5 kilograms (9.9 lb) for males and 6 kilograms (13.2 lb) for females. It has a wingspan of 184 to 202 cm (6 to 6.6 ft). The maximum reported weight is surpassed by two other eagles (the Harpy and Steller's Sea Eagle) and the wings are shorter than large eagles of open country (such as the Martial Eagle
Martial Eagle
The Martial Eagle , is a very large eagle found in open and semi-open habitats of sub-Saharan Africa. It is the only member of the genus Polemaetus.-Description:...
, Wedge-tailed Eagle
Wedge-tailed Eagle
The Wedge-tailed Eagle , sometimes known as the Eaglehawk in its native range, is the largest bird of prey in Australia, but it is also found in southern New Guinea. It has long, fairly broad wings, fully feathered legs, and an unmistakable wedge-shaped tail...
and Steller's Sea Eagle), but are quite broad.
The most frequently heard noises made by the Philippine Eagle are loud, high-pitched whistles ending with inflections in pitch. Additionally, juveniles have been known to beg for food by a series of high-pitched calls.
Distribution and habitat
The Philippine Eagle is endemic to the PhilippinesPhilippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
and can be found on four major islands: eastern Luzon
Luzon
Luzon is the largest island in the Philippines. It is located in the northernmost region of the archipelago, and is also the name for one of the three primary island groups in the country centered on the Island of Luzon...
, Samar
Samar
Samar, formerly and also known as Western Samar, is a province in the Philippines located in the Eastern Visayas region. Its capital is Catbalogan City and covers the western portion of Samar as well as several islands in the Samar Sea located to the west of the mainland...
, Leyte
Leyte
Leyte is a province of the Philippines located in the Eastern Visayas region. Its capital is Tacloban City and occupies the northern three-quarters of the Leyte Island. Leyte is located west of Samar Island, north of Southern Leyte and south of Biliran...
and Mindanao
Mindanao
Mindanao is the second largest and easternmost island in the Philippines. It is also the name of one of the three island groups in the country, which consists of the island of Mindanao and smaller surrounding islands. The other two are Luzon and the Visayas. The island of Mindanao is called The...
. The largest number of eagle
Eagle
Eagles are members of the bird family Accipitridae, and belong to several genera which are not necessarily closely related to each other. Most of the more than 60 species occur in Eurasia and Africa. Outside this area, just two species can be found in the United States and Canada, nine more in...
s reside on Mindanao, with between 82 and 233 breeding pairs. Only six pairs are found on Samar, two on Leyte, and a few on Luzon. It can be found in Northern Sierra Madre National Park
Sierra Madre (Philippines)
The Sierra Madre is a mountain range in The Philippines. It is located along the north-eastern coast of Luzon Island, running north/south. Quezon National Forest Park is situated in the range.-Geography:...
on Luzon and Mount Apo
Mount Apo
Mount Apo is a large solfataric, potentially-active stratovolcano in the island of Mindanao, Philippines. With an altitude of , it is the highest mountain in the country and is located between Davao City and Davao del Sur province in Region XI and Cotabato province in Region XII...
and Mount Kitanglad National Park
Mount Kitanglad
Mount Kitanglad is an inactive volcanic volcano located in the Kitanglad Mountain Range in Bukidnon province on Mindanao island. It is officially declared as the fourth highest mountain in the Philippines and has an approximate height of 2,899 meters...
s on Mindanao.
This eagle is found in dipterocarp and mid-montane forests, particularly in steep areas. Its elevation ranges from the lowlands to mountains of over 1800 metres (5,905.5 ft). It is estimated that only 9220 square kilometres (2,278,309.6 acre) of old growth forest remain in the bird's range. However, its total estimated range is about 146000 square kilometres (56,370.9 sq mi).
Ecology and behavior
Evolution in the Philippine islands, without other predators, made the eagles the dominant hunter in the Philippine forests. Each breeding pair requires a large home range to successfully raise a chick, and thus the species is extremely vulnerable to deforestationDeforestation
Deforestation is the removal of a forest or stand of trees where the land is thereafter converted to a nonforest use. Examples of deforestation include conversion of forestland to farms, ranches, or urban use....
. Earlier it has been estimated that the territory
Territory (animal)
In ethology the term territory refers to any sociographical area that an animal of a particular species consistently defends against conspecifics...
is about 100 square kilometre, but a study on Mindanao Island found the nearest distance between breeding pairs to be about 13 kilometres (8.1 mi) on average, resulting in a circular plot of 133 square kilometre.
The species' flight is fast and agile, resembling the smaller hawks more than similar large birds of prey.
Juveniles in play behavior have been observed gripping knotholes in trees with their talons and, using its tail and wings for balance, inserting its head into a tree cavity. Additionally, they have been known to attack inanimate objects for practice as well as attempt to hang upside down to work on their balance. As the parents are not nearby when this occurs, it has been suggested that they do not play a role in teaching the juvenile to hunt.
Life expectancy for a wild eagle is estimated to be anywhere from 30 to 60 years. A captive Philippine Eagle lived for 41 years in Rome Zoo, and it was already adult when it arrived at the zoo. However, it is believed that wild birds on average live shorter lives than captive birds.
Diet
The Philippine Eagle was known initially as the Philippine Monkey-Eating Eagle because it was believed to feed on monkeys (the only monkey native to the Philippines is the Philippine long-tailed macaquePhilippine Long-tailed Macaque
The Philippine long-tailed macaque is a subspecies of the crab-eating macaque. It is found in most Philippine forests and woodlands, but especially in the mangrove forests of western central Philippines— particularly in Palawan, the Visayas, and Mindanao. The names M. f. philippinensis or...
) exclusively; this has proven to be inaccurate. The primary prey varies from island to island depending on species availability, particularly in Luzon and Mindanao. This is due to the islands being in different faunal regions. For example, Philippine flying lemur
Philippine Flying Lemur
The Philippine Flying Lemur is one of two species of flying lemurs, the only two living species in the order Dermoptera. Additionally, it is the only member of the genus Cynocephalus.-Distribution:...
s, the preferred prey in Mindanao, are absent in Luzon. The primary prey for the eagles seen in Luzon are monkeys, birds, flying foxes
Pteropus
Bats of the genus Pteropus, belonging to the megabat or Megachiroptera sub-order, are the largest bats in the world. They are commonly known as the fruit bats or flying foxes among other colloquial names...
, giant cloud-rats Phloeomys pallidus
Northern Luzon Giant Cloud Rat
The Northern Luzon Giant Cloud Rat is a large species of rodent in the family Muridae. It is only found in the northern and central part of Luzon, the Philippines. It prefers forest and scrub, but also occurs in degraded habitats such as plantations. It occurs from sea level to an altitude of about...
which can weigh twice as much as flying lemurs (that is, 2 to 2.5 kg), and reptiles such as large snakes and lizards. The eagles prefer flying lemurs and Asian Palm Civets, but they occasionally eat small mammals, birds (owl
Owl
Owls are a group of birds that belong to the order Strigiformes, constituting 200 bird of prey species. Most are solitary and nocturnal, with some exceptions . Owls hunt mostly small mammals, insects, and other birds, although a few species specialize in hunting fish...
s and hornbill
Hornbill
Hornbills are a family of bird found in tropical and subtropical Africa, Asia and Melanesia. They are characterized by a long, down-curved bill which is frequently brightly-colored and sometimes has a casque on the upper mandible. Both the common English and the scientific name of the family...
s), reptiles (snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
s and monitor lizard
Monitor lizard
Monitor lizards are usually large reptiles, although some can be as small as in length. They have long necks, powerful tails and claws, and well-developed limbs. Most species are terrestrial, but arboreal and semiaquatic monitors are also known...
s), and even other birds of prey. There have been reports of eagles capturing young pigs and small dogs. It is estimated that the flying lemur could make up 90% of the raptor's diet in some locations.
Eagle pairs sometimes hunt troops of monkey cooperatively, with one bird perching nearby to distract the primates allowing the other to swoop in unnoticed for the kill.
Reproduction
The beginning of courtship is signaled by nest-building and the eagle remaining near its nest. Aerial displays also play a major role in the courtship. These displays include paired soaring over a nesting territory, the male chasing the female in a diagonal dive, and mutual talon presentation, where the male presents his talons to the female's back and she flips over in mid-air to present her own talons. Advertisement displays coupled with loud calling have also been reported. The willingness of an eagle to breed is displayed by the eagle bringing nesting materials to the bird's nest. Copulation follows and occurs repeatedly both on the nest and on nearby perches. The earliest courtship has been reported in July.
Breeding begins between September and February; birds on different islands, most notably Mindanao and Luzon, begin breeding at different ends of this range. The amount of rainfall and population of prey may also affect the breeding season. The nest is normally built on an emergent dipterocarp, or any tall tree with an open crown, in primary or disturbed forest and may be nearly 1.5 metres (4.9 ft) across and about 30 metres (98.4 ft) above the ground. The eagle's nest resembles a huge platform made of sticks. The eagle frequently reuses the same nesting site for several different chicks. Eight to ten days before the egg is ready to be laid, the female is afflicted with a condition known as egg lethargy. In this experience, the female does not eat, drinks lots of water, and holds its wings droopingly. The female typically lays one egg in the late afternoon or at dusk, although occasionally two have been reported. If an egg fails to hatch or the chick dies early, the parents will likely lay another egg the following year. Copulation may last a few days after the egg is laid to enable another egg to be laid should the first one fail. The egg is incubated for 58 to 68 days after being laid. Both sexes participate in the incubation, but the female does the majority of incubating during the day and all of it at night.
Both sexes help feed the newly hatched eaglet. Additionally, the parents have been observed taking turns shielding the eaglet from the sun and rain until it is seven weeks old. The young eaglet fledges after four or five months. The earliest an eagle has been observed making a kill is 304 days after hatching. Both parents take care of the eaglet for a total of twenty months.
Conservation
BirdLife International
BirdLife International is a global Partnership of conservation organisations that strives to conserve birds, their habitats and global biodiversity, working with people towards sustainability in the use of natural resources...
listed this species as critically endangered
Critically endangered
Version 2010.3 of the IUCN Red List of Threatened Species identified 3744 Critically Endangered species, subspecies and varieties, stocks and subpopulations.Critically Endangered by kingdom:*1993 Animalia*2 Fungi*1745 Plantae*4 Protista-References:...
. The International Union for the Conservation of Nature believes that between 180 and 500 Philippine Eagles survive in the Philippines. They are threatened primarily by deforestation through logging and expanding agriculture. Old growth forest is being lost at a high rate, and most of the eagle's forest in the lowlands is owned by logging companies. Mining, pollution, exposure to pesticides that affect breeding, and poaching
Poaching
Poaching is the illegal taking of wild plants or animals contrary to local and international conservation and wildlife management laws. Violations of hunting laws and regulations are normally punishable by law and, collectively, such violations are known as poaching.It may be illegal and in...
are also major threats. Additionally, they are occasionally caught in traps laid by local people for deer. Though this is no longer a major problem, the eagle's numbers were also reduced by being captured for zoos.
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 then director of the Parks and Wildlife Office, Jesus A. Alvarez. Charles Lindbergh
Charles Lindbergh
Charles Augustus Lindbergh was an American aviator, author, inventor, explorer, and social activist.Lindbergh, a 25-year-old U.S...
, best known for crossing the Atlantic alone and without stopping in 1927, was fascinated by this eagle. 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. In 1969, the Monkey-eating Eagle Conservation Program was started to help preserve this species. In 1992, the first Philippine Eagles were born in captivity through artificial insemination
Artificial insemination
Artificial insemination, or AI, is the process by which sperm is placed into the reproductive tract of a female for the purpose of impregnating the female by using means other than sexual intercourse or natural insemination...
; however, it was not until 1999 that the first naturally bred eaglet hatched. The first captive-bred bird to be released in the wild, Kabayan, was released in 2004 on Mindanao; however, he was accidentally electrocuted in January 2005. Another eagle, Kagsabua, was released March 6, 2008, but was shot and eaten by a farmer. Killing this critically endangered species is punishable under Philippine law by twelve years in jail and heavy fines.
Its numbers have slowly dwindled over the decades to the current population of 180 to 500 eagles. A series of floods and mud slides, caused by deforestation, further devastated the remaining population. The Philippine Eagle may soon no longer be found in the wild, unless direct intervention is taken. The Philippine Eagle Foundation of Davao City
Davao City
The City of Davao is the largest city in the island of Mindanao in the Philippines. Its international airport and seaports are among the busiest cargo hubs in the Philippines....
, Mindanao
Mindanao
Mindanao is the second largest and easternmost island in the Philippines. It is also the name of one of the three island groups in the country, which consists of the island of Mindanao and smaller surrounding islands. The other two are Luzon and the Visayas. The island of Mindanao is called The...
is one organization dedicated to the protection and conservation of the Philippine Eagle and its forest habitat. The Philippine Eagle Foundation has successfully bred Philippine Eagles in captivity for over a decade and conducted the first experimental release of a captive-bred eagle to the wild. The foundation has 32 eagles at its center, of which 18 were bred in captivity. Ongoing research on behavior, ecology and population dynamics is also underway. In recent years protected lands have been established specifically for this species, such as the 700 square kilometres (172,973.6 acre) Cabuaya Forest and the 37.2 square kilometres (9,192.3 acre) Taft Forest Wildlife Sanctuary on Samar. However, a large proportion of the population is found on unprotected land.
Relationship with humans
The Philippine Eagle was officially declared the national bird of the Philippines on 4 July 1995 by President Fidel V. RamosFidel V. Ramos
Fidel "Eddie" Valdez Ramos , popularly known as FVR, was the 12th President of the Philippines from 1992 to 1998. During his six years in office, Ramos was widely credited and admired by many for revitalizing and renewing international confidence in the Philippine economy.Prior to his election as...
under Proclamation No. 615. This eagle, because of its size and rarity, is also a highly desired bird for birdwatchers.
The Philippine Eagle has also featured on at least twelve stamps from the Philippines, with dates ranging from 1967 to 2007. It was also depicted on the 50 centavo coins minted from 1981 to 1994.
Historically, about 50 Philippine Eagles have been kept in zoo
Zoo
A zoological garden, zoological park, menagerie, or zoo is a facility in which animals are confined within enclosures, displayed to the public, and in which they may also be bred....
s in Europe (England, Germany, Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
, Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
and France), United States and Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
. The first was a female that arrived in London Zoo
London Zoo
London Zoo is the world's oldest scientific zoo. It was opened in London on 27 April 1828, and was originally intended to be used as a collection for scientific study. It was eventually opened to the public in 1847...
in August 1909 and died there in February 1910. The majority arrived in zoos between 1947 and 1965. The last outside the Philippines died in 1988 in the Antwerp Zoo
Antwerp Zoo
Antwerp Zoo is a zoo in the centre of Antwerp, Belgium, located right next to the Antwerpen-Centraal railway station. It is the oldest animal park in the country, and one of the oldest in the world, established on 21 July 1843.- History :...
where it had lived since 1964 (except for a period at the Planckendael Zoo in Belgium). The first captive breeding was only achieved in 1992 at the facility of the Philippine Eagle Foundation in Davao City
Davao City
The City of Davao is the largest city in the island of Mindanao in the Philippines. Its international airport and seaports are among the busiest cargo hubs in the Philippines....
, Mindanao, the Philippines, which has bred it several times since then.
See also
- List of endemic birds of the Philippines
- List of birds of the Philippines
- Haast's EagleHaast's EagleHaast's Eagle was a species of massive eagles that once lived on the South Island of New Zealand. The species was the largest eagle known to have existed. Its prey consisted mainly of gigantic flightless birds that were unable to defend themselves from the striking force and speed of these eagles,...
External links
- Philippine Eagle Foundation. A foundation devoted to saving the Philippine Eagle.
- Animal Diversity Web - Pithecophaga jefferyi
- National Geographic Magazine - "The Lord of the Forest"
- Bringing Back Ol' Blue Eyes - article on Philippine Eagle Foundation work on Mindanao
- Video of Philippine eagle hunting flying lemurs
- Photos of the Philippine Eagle by Klaus Nigge