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Philippine Hawk-eagle Nisaetus philippensis

This raptor qualifies as Vulnerable because its very small population, of which the majority is in two main subpopulations, is undergoing a continuing and rapid decline owing to lowland forest loss, exacerbated by hunting and trade.

Taxonomic source(s)
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.

Taxonomic note
Spizaetus philippensis (Sibley and Monroe 1990, 1993) was split into S. philippensis and S. pinskeri by Gamauf et al. (2005), but this treatment has not been adopted by the BirdLife Taxonomic Working Group. Although the group accepts that pinskeri is well differentiated genetically, the case for separation at species level, taking account of the morphological character differences given by Gamauf et al. (1999), is not fully convincing. Spizaetus nanus, S. lanceolatus, S. philippensis, S. pinskeri, S. nipalensis, S. alboniger and S. bartelsi (Sibley and Monroe 1990, 1993) and S. cirrhatus and S. floris (Gjershaug et al. 2004) have been transferred into the genus Nisaetus following Haring et al. (2006). S. africanus and Hieraaetus fasciatus (Sibley and Monroe 1990, 1993) have both been transferred into Aquila, also following Haring et al. (2006); and H. kienerii (Sibley and Monroe 1990, 1993) has been transferred into the resurrected genus Lophotriorchis. The BirdLife Taxonomic Working Group is aware that phylogenetic analyses have been published which have proposed moving H. pennatus into Aquila but as not all published studies are concordant we prefer not to take a decision on this until cladogenesis of the 'booted eagles' has been resolved.

65-70 cm. Medium-sized eagle with longish, black crest. Rufescent-brown crown and face, streaked darker. Dark brown upperparts. Brown tail with 4-5 darker bars. White throat, bordered by dark malars. Black mesial stripe. Rufous underparts with black streaking. Finely barred black-and-white "trousers". Pale iris. In flight, shows broad, rounded wings and well-barred flight feathers. Juvenile has white head and underparts, upperparts fringed paler. Acquires adult plumage over four years. Similar spp. Difficult to separate from Barred Honey-buzzard Pernis celebensis and Changeable Hawk-eagle Spizaetus cirrhatus unless seen well. Combination of long crest and feathered legs diagnostic. Voice Loud, disyllabic whistle. Hints Look around forest edge.

Distribution and population
Spizaetus philippensis is endemic to the Philippines, where there are records from c.60 sites on at least 12 islands (Collar et al. 1999). Since 1980, there have been records from 15 localities on Luzon (primarily in the Sierra Madre mountains), 13 on Mindanao and six on Mindoro, Bohol, Negros and possibly Panay, combined. Historically, the species was rare, and the spate of recent records - most of unconfirmed identification - does not change that impression. Although relatively common at one site on Mindanao, it is uncommon in the Sierra Madre lowlands, very scarce on Mindoro and Negros, and is very probably already extinct on some smaller islands within its former range (e.g. Siquijor). Following recent fieldwork, 200-220 pairs were estimated to remain on Luzon and 320-340 pairs on Mindanao. If these estimates are accurate, the overall population must be very low.

Population justification
The species strongholds appear to be Luzon and Mindanao where 200-220 pairs and 320-340 pairs respectively were recently estimated. Therefore, the global population is probably best placed in the band 1,000-2,499 individuals. This equates to 667-1,666 mature individuals, rounded here to 600-1,700 mature individuals.

Trend justification
The species is suspected to be declining rapidly, owing to the on-going loss and conversion of its forest habitat for logging and plantation agriculture.

It inhabits primary, selectively logged and disturbed forest, occasionally frequenting open areas, from the lowlands to lower mountain slopes, almost exclusively below 1,000 m. It appears not to tolerate much forest degradation. No migration is known, although unconfirmed reports from the migration funnel of Dalton Pass (Luzon) hint at intra-island movements.

Deforestation for plantation agriculture, livestock and logging throughout its extensive, predominantly lowland range is the chief threat. In 1988, forest cover was as low as 24% on Luzon and 29% on Mindanao and these figures are likely to be overestimates, with most lowland forest leased to logging concessions. Habitat loss is exacerbated by considerable hunting and trapping pressure.

Conservation Actions Underway
CITES Appendix II. It has been recorded recently from numerous protected areas, including Mts Isarog and Makiling National Parks, the Northern Sierra Madre Natural Park and Bataan Natural Park/Subic Bay on Luzon, Mt Canlaon on Negros, and Mt Kitanglad and Mt Apo Natural Parks and Mt Malindang on Mindanao, and Rajah Sikatuna National Park on Bohol and recently on Mount Irid-Angilo-Binuang of the Southern Sierra Madre in Luzon (J. Ibanez in litt. 2007), as well as Tadao Ilocos Norte, Mt Palay Palay and Mt Banahao (D. Allen in litt. 2012). These sites are legally protected through local government decrees, but the efficacy of this legislation is often unclear and is ineffective at Mt Malindang and in the Southern Sierra Madre (D. Allen in litt. 2012). The species is regularly recorded during surveys for Philippine Eagle Pithecophaga jeffreyi in Luzon (J. Ibanez in litt. 2007).
Conservation Actions Proposed
Conduct further surveys in areas from which the species is known (e.g. Mt Los Dos Cuernos on Luzon, Mts Cabalantian/Capoto-an on Samar), which may merit formal protection. Study the species's ecology, particularly home-range size and dispersal ability to help inform a global population estimate and assess the likely impact of habitat fragmentation. Promote more effective enforcement of legislation designed to control hunting and trading. Gazette the proposed Southern Sierra Madre Protected Landscape. Use remote-sensing to assess forest loss in the Philippines and gauge the species's likely rate of decline and degree of fragmentation of its populations. Research hunting and trade by interviewing local people and visiting wildlife markets.

Collar, N. J.; Mallari, N. A. D.; Tabaranza, B. R. J. 1999. Threatened birds of the Philippines: the Haribon Foundation/BirdLife International Red Data Book. Bookmark, Makati City.

Further web sources of information
Detailed species accounts from the Threatened birds of Asia: the BirdLife International Red Data Book (BirdLife International 2001).

Text account compilers
Benstead, P., Bird, J., Lowen, J., Taylor, J.

Allen, D., Ibanez, J.

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2014) Species factsheet: Nisaetus philippensis. Downloaded from on 22/07/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from on 22/07/2014.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Additional resources for this species

ARKive species - Philippine hawk-eagle (Spizaetus philippensis) 0

Key facts
Current IUCN Red List category Vulnerable
Family Accipitridae (Osprey, kites, hawks and eagles)
Species name author (Gould, 1863)
Population size 600-1700 mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 260,000 km2
Country endemic? Yes
Links to further information
- Additional Information on this species