Justification of Red List Category
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.
Bueser et al. (2003) estimated the population on Mindanao to number 82-233 pairs. Numbers elsewhere are tiny: perhaps six pairs on Samar, two on Leyte and probabaly very few on Luzon, giving a total population size of perhaps 90-250 pairs, or 180-500 mature individuals, roughly equating to 250-750 individuals in total.
An extremely rapid decline is suspected to have taken place over the last three generations, based on rates of habitat loss in the past (given this species's presumably long generation length), which are on-going.
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 pairs (Bueser et al. 2003). Estimates from other islands are of six pairs on Samar and perhaps two on Leyte, and at least one on Luzon (in 2015 a Philippine Eagle Foundation survey team found the first active Philippine Eagle nest in Apayao province [Ranada 2015]); but these should be considered precautionary figures (Collar et al. 1999). An earlier estimate using 1992 forest-cover data suggested 226 mature individuals, with a total population, including immatures, of c. 350-670 birds. Extrapolations across all islands based on the density of nests located on Mindanao suggest a total of 340 pairs; however, it is unknown whether the species reaches similar densities on the other islands, particularly Luzon, and this figure should perhaps be treated with caution (Miranda et al. 2008). Poor recruitment to the breeding population was previously thought to be a key factor in this species's decline (Miranda 2006), but recent research suggests that the dispersal and survival of juveniles and subadults is of greater concern (Miranda et al. 2008). The first release of a captive-reared bird took place in 2004 when a male was released into the forest of Mount Apo, Mindanao (Block 2004). Unfortunately this bird was electrocuted nine months after release, and another rehabilitated bird released on Mindanao in 2008 was killed by a hunter four months after release, but further experimental releases are planned (J. Ibanez in litt. 2008, Philippine Eagle Foundation 2008), preceding a full scale reintroduction programme to supplement wild populations (Salvador and Ibañez 2006).
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. On Mindanao the primary prey species is the Philippine Flying Lemur Cynocephalus volans, which is absent from Luzon where the species was found to prey on two endemic species of Cloud Rats (Hurrell 2014). A range of other prey are taken, including palm civets Paradoxurus, snakes, monitor lizards, birds, bats and monkeys (Clark et al. 2015). 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 (Miranda et al. 2008). 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 (Ibañez et al. 2003). A complete breeding cycle lasts two years, with successful pairs raising one offspring (Ibañez et al. 2003). Birds form a monogamous bond for life with sexual maturity for females at around five years and for males at around seven years (J. Ibanez in litt. 2008). The young fledge after c.4-5 months, but stay in the nest vicinity for almost a year and a half (J. Ibanez in litt. 2008). Captive birds have reached more than 40 years of age (J. Ibanez in litt. 2008).
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 9,220 km2 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 (Miranda et al. 2008). Naive juvenile birds are easily shot or trapped, as are adults nesting near forest edges (J. Ibanez in litt. 2008). 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 (J. Ibanez in litt. 2008). Pesticide accumulation is another potential but unproven threat which may reduce its already slow reproductive output. Severe weather events, such as Typhoon Haiyan in 2013, may have an impact on the species (De Win 2013).
Conservation Actions Underway
CITES Appendix I. The species occurs in several protected areas including the Northern Sierra Madre Natural Park on Luzon, and Mt Kitanglad and Mt Apo Natural Parks on Mindanao.
Since 1970, various initiatives have been launched, including the passing of legislation prohibiting persecution and protecting nests, conducting survey work, public awareness campaigns, captive breeding and a socio-economic project to alleviate pressure on an eagle territory whilst increasing local economic prosperity. Haribon Foundation, the Species Guardian, has implemented an extensive program of education and outreach throughout Luzon, including engaging science teachers to develop a module including information on biodiversity and conservation with the Philippine Eagle as the flagship species (Haribon Foundation in litt. 2013). The project has engaged with 1,200 students and two indigenous communities (Hurrell 2014). Participation at regional events and radio broadcasts have also taken place (Haribon Foundation in litt. 2013). Additionally, slash and burn agriculture is regulated by a local ordinance in the forest in which the active nest was found on Luzon, and 'green guards' are used to protect the forest habitat (Ranada 2015).
The Philippine Eagle Foundation runs the Philippine Eagle Centre in Davao City, Mindanao, and oversees captive-breeding efforts and monitoring and conservation of wild populations (Salvador 2004). In 2008, there were 32 eagles at the centre, 18 of which were captive bred, and the Foundation is working towards the development of a full reintroduction programme (Philippine Eagle Foundation 2008).
Conservation Actions Proposed
Conduct further research into distribution, numbers, ecological needs and threats. Extend the protected-areas system to embrace known eagle nests and habitat. Implement habitat management schemes for the benefit of wildlife and local people. Integrate eagle-friendly practices into forestry policy. Launch a campaign to engender national pride and respect for the eagle. Develop support for the Philippine Eagle Conservation Plan at the local level (Haribon Foundation 2013). Investigate genetic differences between birds on Luzon and those on Mindanao, Samar and Leyte and take findings into account when planning releases of captive-bred and rehabilitated birds (Miranda et al. 2008). Implement further research and develop conservation actions for the species in the Sierra Madre mountains (Haribon Foundation 2013).
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. Voice Loud, high-pitched whistles. Begging juvenile gives regular series of high-pitched cries. Hints Generally unobtrusive. Adults occasionally display on warm mornings. Listen for begging juveniles which are dependent on parents for many months.
Text account compilers
Taylor, J., Martin, R., Ashpole, J, Bird, J., Westrip, J., Butchart, S., Lowen, J., Benstead, P., Symes, A.
BirdLife International (2021) Species factsheet: Pithecophaga jefferyi. Downloaded from http://www.birdlife.org on 30/07/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 30/07/2021.