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Aug 27 2011

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Philippine Eagle (Pithecophaga jefferyi)

Philippine Eagle

[order] ACCIPITRIFORMES | [family] Accipitridae | [latin] Pithecophaga jefferyi | [authority] Ogilvie-Grant, 1897 | [UK] Philippine Eagle | [FR] Aigle des singes | [DE] Affenadler | [ES] Aguila monera | [NL] Apenarend

Subspecies

Monotypic species

Genus

Pithecophaga jefferyi is one of the largest and rarest birds of prey in the world and lives in the Philippine islands of Luzon, Leyte, Mindanao and Samar. The generic name of the Philippine Eagle, Pithecophaga, which led to its original English name ?monkey-eating?, was the result of the natives of Samar reporting that it ?preys chiefly on the Green Monkeys. A recent study of the Philippine Eagles’ DNA suggests that the Philippine’s national bird is one of a kind. Not only is it found nowhere else, it has a unique evolutionary history, clearly distinguishing it from other giant eagles once thought of as its immediate family. Scientists from the University of Michigan, in the USA, analyzed DNA isolated from blood samples of the Philippine Eagle and those of the Harpy Eagle and Crested eagles of the Americas and the New Guinea Harpy Eagle, all equal heavyweights of the bird world. All of the last three giants named are close relatives as revealed by DNA sequences, but only remotely related to the Philippine Eagle. All of the five traditional “harpy eagle group” members live in tropical forests, feeding mainly on medium-sized mammals. Based on the genetic analysis, the similarities between the Philippine Eagle and the other harpies resulted not from kinship but from convergent change, driven by natural selection for reproductive success in tropical forests and a shared taste for mammals. The only distant relatives of Philippine Eagles are snake eagles found elsewhere in Southeast Asia and far Africa. In the Philippines, it is distantly related to the featherweight but equally imposing Serpent Eagle, which breeds in this country but is also common in Asia.

Physical charateristics

86-102 cm. Huge eagle with large, deep bill and elongated nape feathers forming shaggy crest. Dark face, creamy-buff crown and nape with black shaft-streaks. Rest of upperparts dark brown. White underparts and underwings. Pale grey iris, dark grey bill, yellow legs with huge dark claws. Juvenile as adult but upperpart feathers fringed pale. This very large eagle (the female noticeably larger than the male) is among the most powerful raptors, and is one of the largest and most striking forest eagles in the world. The feathers of the upper parts are dark brown edged with buff. The underparts are off white, streaked with rufous on the throat, thighs and underwing coverts. The head is surmounted by a crest of long pale rufous feathers streaked with dark brown. The eyes are blue-gray, the cere blue-green and the massive bare legs and feet are pale yellow. The black bill is exceptionally deep and prominent. Immatures resemble the adults, and the sexes are similar. The vast size, generally dark brown colour above, whitish below, and huge, laterally compressed bill characterise this eagle. In flight the wings are broad and rounded and the tail long.

Listen to the sound of Philippine Eagle

[audio:http://www.planetofbirds.com/MASTER/ACCIPITRIFORMES/Accipitridae/sounds/Philippine Eagle.mp3]

Copyright remark: Most sounds derived from xeno-canto


wingspan min.: 184 cm wingspan max.: 202 cm
size min.: 86 cm size max.: 102 cm
incubation min.: 60 days incubation max.: 61 days
fledging min.: 160 days fledging max.: 170 days
broods: 1   eggs min.: 1  
      eggs max.: 1  

Range

Oriental Region : Philippines. Pithecophaga jefferyi is endemic to the Philippines, where it is known from eastern Luzon, Samar, Leyte and Mindanao. Mindanao supports the bulk of the population, with recent research estimating 82-233 breeding pairs1. Estimates from other islands are of six pairs on Samar and perhaps two on Leyte, and Luzon may have very few left

Habitat

It inhabits primary dipterocarp forest, particularly in steep terrain, sometimes frequenting secondary growth and gallery forest (but not occupying open canopy forest), from lowlands to at least 1,800 m. Estimates based on the distribution of nests in Mindanao suggest that each pair covers an average of 133 km2, including an average of 68 km2 of forest.

Reproduction

A huge nest high in a forest tree is used over successive years and the pair may soar in the area of the nest before breeding. Both sexes line the nest with green leaves and a single egg is incubated, mostly by the female, for about 60 days. The male delivers food to the nest throughout the breeding cycle until assisted by the female in the latter half of the 160-day nestling period. The young only try to catch their own prey four or five months after leaving the nest and, with such a prolonged cycle, successful breeding may only occur in alternate years. On Mindanao eagles begin nesting from September to December in primary and disturbed forest, with some differences in the timing of breeding between Mindanao and Luzon. A complete breeding cycle lasts two years with successful pairs raising one offspring. Birds form a monogamous bond for life with sexual maturity for females at around five years and for males at around seven years. Captive birds have reached more than 40 years of age.

Feeding habits

Arboreal mammals, such as flying lemurs and squirrels, are the most important food. Monkeys, deer, palin civets, bats, snakes, monitor lizards and large birds, such as hornbills and young owls are also taken at times. It is reputed by locals to take young pigs.

Video Philippine Eagle

httpv://www.youtube.com/watch?v=q2MJ0i1IGR0

copyright: National Geographic


Conservation

This long-lived species qualifies as Critically Endangered because it has an extremely small population, as a result of extremely rapid declines in the past three generations (56 years) owing to extensive deforestation. Recruitment to the adult population currently appears to be very low indicating that declines may continue into the future. Confirmation of trends is required and may lead to a change in status in the future.
Forest destruction and fragmentation, through commercial timber extraction and shifting cultivation, is the principal long-term threat. Old-growth forest continues to be lost rapidly, such that as little as 9,220km2 may remain within the eagle’s range. Moreover, most remaining lowland forest is leased to logging concessions. Mining applications pose an additional threat. Uncontrolled hunting (for food and, at least formerly, zoo exhibits and trade) is perhaps the most significant threat in the short term. Naive juvenile birds are easily shot or trapped, as are adults nesting near forest edges. Birds are also vulnerable to accidental capture in traps intended for wild pigs and deer, and there are several records of individuals caught in snares presumably whilst hunting on the forest floor. Pesticide accumulation is another potential but unproven threat which may reduce its already slow reproductive output.
Philippine Eagle status Critically Endangered

Migration

Adults are sedentary, but juveniles disperse from breeding areas

Distribution map

Philippine Eagle distribution range map

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Permanent link to this article: http://www.planetofbirds.com/accipitriformes-accipitridae-philippine-eagle-pithecophaga-jefferyi

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