Data Zone
Justification of Red List category
This raptor is endemic to the Philippines, where it is confined to Luzon and Mindoro in the country's north. It is confined to forest which has been heavily depleted and now likely has a population below 2,500 mature individuals. Given ongoing pressures of habitat loss, and perhaps hunting, declines are thought to be ongoing and therefore the species is interpreted as being at a high risk of extinction. It is accordingly listed as Endangered.
Population justification
Endemic to Luzon (and satellites) and Mindoro, where considered uncommon to rare (Allen 2020). During fieldwork at two sites on Luzon, Preleuthner and Gamauf (1998) determined population densities of 3.1–5.7 pairs/100km2, broadly similar to more recent road transect surveys in 2021 which found c.0.4–0.5 individuals/10 km of road travelled (J. Gan in litt. 2021). From their data, Preleuthner and Gamauf (1998) concluded a population size on Luzon of 200–220 pairs.
It is unclear from what source Preleuthner and Gamauf (1998) derived their extent of suitable habitat value to extrapolate population densities into population sizes, but it appears to have been pessimistic. Recent remote sensing data (Global Forest Watch 2024) combined with citizen science data (eBird 2024) indicate that there is approximately 15,000–20,000 km2 of suitable forest on Luzon alone, indicating a population size of 465–855 breeding pairs, or 930–1,710 mature individuals.
Mindoro was not mentioned as being part of this taxon's range by Preleuthner and Gamauf (1998), despite being listed by Dickinson et al. (1991) and Dutson et al. (1992). It continues to be regularly observed here (eBird 2024) and, if densities on Mindoro are equivalent to Luzon, the island probably hosts an additional 50–100 pairs.
Combining available data the global population size is therefore estimated at c.1,000–2,000 mature individuals.
Trend justification
The primary threat to this species is deforestation, with hunting a secondary threat which may have additive impacts (although its contribution to declines is much harder to quantify). Between 2000 and 2022, forest cover in this species' range fell by 7–14%, depending on the thresholds of canopy cover used in the calculation (Global Forest Watch 2023, based on data from Hansen et al. [2013] and methods disclosed therein). Selective logging, forest degradation and hunting are all likely to be having additive impacts on this species, although these are difficult to quantify. Accounting for all plausible scenarios (including the pattern of recent records [eBird 2024], which indicate the species does remain relatively common/frequently observed in suitable habitat; i.e. hunting is probably not an acute threat), over the past three generations (26 years: 1996–2022) this species is suspected of having declined by 10–25%. More recently, annual forest cover loss in this species' range has slowed, in large part because of an increasing successful protected area network (Apan et al. 2017, Blankespoor et al. 2017). Nonetheless, some forest continues to be lost (since 2017 at a rate closer to 4–5% over three generations) and in the future, the population of this species is suspected to decline more slowly, at c.5-15%.
Nisaetus philippensis is endemic to the northern Philippines, where it occurs on Luzon (where the Sierra Madre is likely a stronghold, but records throughout: eBird 2024), and Mindoro (Allen 2020).
It inhabits primary, selectively logged and disturbed forest, occasionally frequenting open areas, from the lowlands to lower mountain slopes, almost exclusively below 1,050 m (Allen 2020), but sporadic records up to at least c.2,000 m. It appears relatively intolerant of forest degradation, with almost all records over primary or well-recovered secondary forest (eBird 2024).
The principal threat to this species is forest cover loss. Although it is sometimes found soaring over agricultural areas, it is considered dependent on the persistence of primary or mature secondary forest. Between 2000 and 2022, forest cover extent in this species' range fell by 7–14%, depending on the thresholds of canopy cover used in the calculation (Global Forest Watch 2024, based on data from Hansen et al. [2013] and methods disclosed therein). The underlying causes of most forest cover loss in its range is plantations and agricultural land-use change. Selective logging, forest degradation and hunting are all likely to having additive impacts on this species, although these are difficult to quantify.
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 and recently on Mount Irid-Angilo-Binuang of the Southern Sierra Madre in Luzon, as well as Tadao Ilocos Norte, Mt Palay Palay and Mt Banahao (D. Allen in litt. 2012, eBird 2024). 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).
65-70 cm. Medium-sized eagle with longish, black crest. Rufescent-brown crown and face, with fine dark streaks. 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 separates N. philippensis and N. pinskeri from the above. N. pinskeri (occurring on the southern Philippine islands and only recently recognised) is very similar, but has ochraceous-tawny throat and breast, and plain brownish belly and underwing coverts. Voice Loud, disyllabic whistle. Hints Look around forest edge.
Text account compilers
Berryman, A.
Contributors
Allen, D., Ibanez, J. & Gan, J.
Recommended citation
BirdLife International (2024) Species factsheet: North Philippine Hawk-eagle Nisaetus philippensis. Downloaded from
https://datazone.birdlife.org/species/factsheet/north-philippine-hawk-eagle-nisaetus-philippensis on 21/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 21/12/2024.