• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Justification of Red List category
This highly forest-dependent species has a small population (<10,000 mature individuals) that is declining owing to ongoing forest loss and degradation within its range. It is therefore assessed as Vulnerable.

Population justification
Undoubtedly scarce. Both Buchanan et al. (2008) and Davis et al. (2017) 'estimated' the global population size to lie in the band 2,500-10,000 mature individuals, although without clear elucidation, whereas Ferguson-Lees and Christie (2001) thought the population to be only in the high hundreds. A coarse GIS exercise suggests that the area of available habitat is no more than c.8,300 km². Accurate density estimates for Accipiter hawks are few, however no forest species is known to exceed 1/km² (see Ferguson-Lees and Christie 2001), thus the estimate of 2,500-10,000 mature individuals is accepted here on the basis that it is highly unlikely to exceed it. Future survey effort should aim to elucidate its true density, however, as it may number considerably fewer.

Trend justification
This species is highly dependent on old-growth forest and occurs at significantly lower densities in degraded forests (Buchanan et al. 2008, Davis et al. 2017, G. Dutson in litt. 2024). Forest loss is ongoing, with remote sensing data relatively insensitive to additional impacts of habitat degradation. As such, a continuing decline can be inferred. Buchanan et al. (2008) calculated the rate of forest loss within the species' range on New Britain as 9.5% over three generations, using a longer three-generation time span of 28.5 years (vs 15.75 years; Bird et al. 2020). Using a recalculation of the generation length (5.25 years; Bird et al. 2020), remote sensing data indicate that forest cover extent in this species' range reduced by c.3% overall in the three generations to 2022 (Global Forest Watch 2023, based on data from Hansen et al. [2013] and methods disclosed therein), and increased rates of loss between 2018-2022 suggest forest loss is currently ongoing at a rate equivalent to 5-6% over three generations. Tentatively, declines are placed in the range 1-9% in three generations and are suspected to continue at the same rate in the future.

Accipiter princeps is endemic to the island of New Britain, Papua New Guinea. It is known from four specimens and a handful of  records (Diamond 1971, Coates 1990, Clay 1994, K. D. Bishop in litt. 1996, G. Dutson pers. obs 1997-1998, Bishop and Jones 2001, eBird 2023). 

Most of the recent records have come from hill and montane forest from 750 to 1,400 m, but it was recorded once at 200 m (Diamond 1971, Coates 1990, Clay 1994, K. D. Bishop in litt. 1996, G. Dutson pers. obs 1997-1998, Dutson 2011, Davis et al. 2017) and there are occasional records from lowland forest, including unconfirmed records down to sea-level (Dutson 2011). Single birds are usually seen perched in subcanopy or flying rather slowly but powerfully through mid-mountain forest. Although the species has been recorded once in degraded montane forest, it is thought that this species is highly dependent on old-growth forest (Buchanan et al. 2008, Davis et al. 2017).

Whilst lowland forests have been extensively logged and cleared for conversion to oil palm on New Britain, there is less logging activity in the mountains and no oil palm. Overall it may be secure in montane forest (Dutson 2011), however slow rates of habitat loss and degradation (Global Forest Watch 2023, based on data from Hansen et al. [2013] and methods disclosed therein) are inferred to be driving slow declines.

Conservation Actions Underway
Listed in CITES Appendix II, although there is no evidence of international trade.

Conservation Actions Proposed
Determine best survey techniques. Survey to assess population size and trends. Map remaining forest, logging concessions, oil palm plantations and proposed expansion areas, and current and proposed mining operations across New Britain. Protect remaining suitable habitat.

Text account compilers
Vine, J.

Contributors
Bishop, K.D. & Dutson, G.

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Recommended citation
BirdLife International (2024) Species factsheet: New Britain Goshawk Accipiter princeps. Downloaded from https://datazone.birdlife.org/species/factsheet/new-britain-goshawk-accipiter-princeps on 27/11/2024.
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 27/11/2024.