Pithecophaga jefferyi

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Philippine Eagle
Pithecophaga jefferyi


Status: Critically endangered

Population Trend: Declining.

Other Names: Great Monkey-eating Eagle, Great Philippine Eagle, Monkey-eating Eagle, Philippine Monkey-eating Eagle.

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Distribution: Indomalayan. Endemic to the islands of northern and eastern PHILIPPINES (Luzon, Leyte, Samar, and Mindanao). more....

Subspecies: Monotypic.

Taxonomy: The recent molecular studies of Lerner and Mindell (2005), recent molecular studies of Lerner and Mindell (2005), based on the molecular sequence from two mitochondrial genes and one nuclear intron, indicated a previously unsuspected close relationship with the Bateleur, Terathopius ecaudatus of Africa. Pithecophaga is sister to a clade of snake eagles (Circaetinae), instead of the clade including the genera Harpia (Harpy Eagle), Morphnus (Crested Eagle), and Harpyopsis (New Guinea Harpy Eagle).

Movements: Non-migratory (Bildstein 2006).

Habitat and Habits: According to Kennedy et al. (2000), these eagles are found in primary forest, forest edge, and logged forest. Salvador and Ibañez (2006) noted that nests have been found in a variety of habitats, ranging from old growth diptocarp forest to second-growth and even highly disturbed areas. These birds generally spend their time within the forest, or at forest edges, but they may soar from one forest fragment to another. As lowland habitats have been cleared, the eagles have become increasingly confined to mountain slopes (Rabor 1971), and most of those studied by Kennedy (1977) were associated with steep mountain slopes forming the sides of deep ravines, canyons, or valleys. Kennedy (op cit.) roughly estimated the size of the home range of a pair of these eagles at 12 to 100 km², a rather wide range.

Food and Feeding Behavior: Preys upon small to medium-sized large mammals, including flying lemurs, civets, flying squirrels, fruit bats, and macaques, medium-sized birds, snakes, and lizards (Kennedy 1985, Ibañez et al. 2003). Hunts from perches in the forest and by probing dense tangles and knotholes in trees (Kennedy et al. 2003). Pairs sometimes hunt cooperatively, with one bird distracting the prey species while the other attacks it from behind (Gonzales 1968). more....

Breeding: Nesting usually begins in September and October on Mindanao. The nest is a huge structure of sticks placed over 30 m high in the main fork of a large tree, often on a platform provided by ferns and orchids. Most nests are over 35 m off the ground. Clutch size is one unmarked white egg. The incubation period is 58-60 days, and the nestling period is 4-5 months. Fledged young are dependent on the parents for up to 17 months, so the breeding cycle lasts two years for successful pairs. Pairs which lose an egg or chick generally re-nest in the succeeding year. (These details are from Kennedy 1985, Miranda et al. 2000, and Ibañez et al. 2003). more....

Conservation: One of the most endangered raptors in the world. In the proximate sense, the principal limiting factor for Philippine Eagle populations is the low survival rates of juveniles and subadults and their inability to disperse across disturbed habitats between forest fragments (Miranda et al. 2000, Salvador and Ibañez op cit.). The fragmentation of habitats renders the species vulnerable to hunting and other forms of persecution, including the capture of birds and nestlings for private and public display (Salvador and Ibañez op cit.). At this time, it seems likely that there is more suitable habitat available for the species than is presently occupied, but habitat loss is the most serious threat to the species in the ultimate sense. Conservation efforts, including captive propagation and pending reintroductions, have been led by the Philippine Eagle Foundation and include captive breeding and reintroduction, conservation education, field research, and community outreach. This species is categorized globally as Critically Endangered by BirdLife International. more....

Population Estimates: The total population was most recently estimated at about 200 pairs in the mountains of Mindanao, where the principal conservation efforts have been concentrated, and at only 500 pairs in the entire country (Salvador and Ibañez 2006). BirdLife International (2009) places the total of mature birds at 180 to 500 individuals. more....

Important References:
Bueser, G.L.L., K.G. Bueser, D.S. Afan, D.I. Salvador, J.W. Grier, R.S.
  Kennedy, and H.C. Miranda, Jr. 2003. Distribution and nesting density of the
  Philippine Eagle Pithecophaga jefferyi on Mindanao Island, Philippines: what
  do we know after 100 years? Ibis 145:130-135.
Clark, W.S. 1994. Great Philippine Eagle. P. 192 in del Hoyo, J., A.
  Elliott, and J. Sargatal (eds). Handbook of birds of the world. Vol. 2. New
  World vultures to guineafowl. Lynx Edicions, Barcelona, Spain.
Collar, N.J. 1997. Species survival versus perpetuation of myth -- the
  case of the Philippine Eagle. Oryx 31:4-7.
Collar, N.J., N.A.D. Mallari, and B.R. Tabaranza, Jr. 1999. Philippine
  Eagle. Pp. 118-179 in Collar, N.J., N.A.D. Mallari, and B.R. Tabaranza, Jr.
  (eds.), Threatened birds of the Philippines. BirdLife International, Makati
  City, Philippines.
Ferguson-Lees, J., and D.A. Christie. 2001. Raptors of the world. Houghton
  Mifflin, Boston, MA.
Gonzales, R.B. 1968. A study of the breeding biology and ecology of the
  Monkey-eating Eagle. Silliman Journal 15:461-491.
Ibañez, J.C., H.C. Miranda, Jr., G. Balaquit-Ibanez, D.S. Afan, and R.S.
  Kennedy. 2003. Observations on the breeding behavior of a Philippine
  Eagle pair at Mount Sinaka, Central Mindanao. Wilson Bulletin 115:333-336.
Kennedy, R.S. 1977. Notes on the biology and status of the Monkey-eating
  Eagle of the Philippines. Wilson Bulletin 89:1-20.
Lerner, H.R., and D.P. Mindell. 2005. Phylogeny of eagles, Old World
  vultures, and other Accipitridae based on nuclear and mitochondrial DNA.
  Molecular Phylogenetics and Evolution 37:327-346.
Miranda, H.C., Jr., D.I. Salvador, J.C. Ibañez, and G.B. Ibañez. 2000.
  Summary of Philippine Eagle breeding success, 1978-1998. Journal of Raptor
  Research 34:37-41.
Miranda, H.C., Jr., D.I. Salvador, G. Lovell, and L. Bueser. 2002. On the
  population biology and status of the Philippine Eagle, Pithecophaga
  jefferyi. Pp. 152-157 in R. Yosef, M.L. Miller, and D. Pepler (eds.),
  Raptors in the new millennium. International Birding & Research Center in
  Eilat, Eilat, Israel.
Salvador, D.J.I., and J.C. Ibañez. 2006. Ecology and conservation of
  Philippine Eagles. Ornithological Science 5:171-176.
more....

Sites of Interest:

Philippine Eagle Foundation
A non-profit organization dedicated to the conservation and protection of this species; maintains a captive breeding program.
Red Data Book Threatened Birds of Asia
Detailed information on status, threats, and conservation measures.
Haribon Foundation
Seeks to conserve habitat for the Phlippine Eagle.
VIREO
Philippine Eagle photos.

Researchers:
Afan, Donald
Concepcion, Camille
Delos Santos, Johannes
Grier, James W.
Hinlo, Maria Rheyda
Ibañez, Jayson
Mindell, David
Sumaya, Anna Mae

Last modified: 6/11/2010

Recommended Citation: Global Raptor Information Network. 2013. Species account: Philippine Eagle Pithecophaga jefferyi. Downloaded from http://www.globalraptors.org on 21 May. 2013