Justification of Red List Category
This species is judged to have a very small population on two islands, and to be declining due to forest clearance and degradation for commercial logging and conversion to oil palm plantations. It is thought to have a single subpopulation. For these reasons, the species is listed as Vulnerable.
There have been few records, despite several surveys taking place in New Britain (Lecroy & Peckover 1983, Bishop & Jones 2001, Davis et al. 2018), suggesting that the species is localised and occurs at low population densities. From 415 hours of survey effort in New Britain in 1997-1998 and in 2010, the species was only observed once (Davis et al. 2018). However, it was recorded on four out of 13 days of surveys in forest on New Ireland (Beehler et al. 2001), so it may be more common in montane forest there, although the area of habitat is much smaller than on New Britain. Based on the area of habitat, the population has been estimated as 2,500-10,000 mature individuals (Buchanan et al. 2008, Davis et al. 2018), although it may be smaller (Davis et al. 2018).
Since congeners have been recorded crossing between islands (Mayr and Diamon 2001), the species is expected to be able to cross the 25 km between New Britain and New Ireland, and so is considered to have a single subpopulation (Davis et al. 2018).
Remote-sensed data on tree cover indicates that approximately 7% of tree cover with at least 50% canopy cover was lost within the species's mapped range over three generations (13 years) from 2006-2019 (Global Forest Watch 2020). Since the species is thought to have a high level of forest dependency (Buchanan et al. 2008), it is inferred that the population size is undergoing a continuing decline. The impact on the species's population size is not known, but based on the rate of deforestation, the species is suspected to have undergone a reduction of 1-9% over the past three generations. Assuming deforestation continues at a similar rate into the future, the species is suspected to undergo a similar reduction in population size over the next three generations.
Accipiter brachyurus is endemic to New Britain and New Ireland in Papua New Guinea. Its true distribution is clouded by identification problems with the other Accipiter species on New Britain, but it is clearly a localised species occurring at low population densities.
This is a poorly-known forest species. Although there are some lowland records (Coates 1985, K. D. Bishop in litt. 1987, I. Burrows in litt. 1994, J. Diamond in litt.1999), most records are from montane forest to 1,800 m (Buchanan et al. 2008, Dutson 2011), including records at 1,200-1,800 m on New Ireland (B. Beehler in litt. 1997, Coates 1985, G. Dutson pers. obs. 1997-1998, Beehler et al. 2001, Dutson 2011). It may be excluded from degraded forest habitats by the common A. novaehollandiae and it may be less common in the lowlands through competition with the similar A. luteoschistaceus. Davis et al. (2018) recorded the species from degraded montane forest so it may have the capacity to cope with some level of disturbance.
Populations are threatened by the extensive logging of lowland and hill forests throughout its range. Large areas of the lowlands of New Britain have been selectively logged over recent decades (Bishop & Jones 2001). In 2002, all forest in West New Britain and most forest in East New Britain was allocated for industrial forestry, and New Britain alone accounted for approximately half of Papua New Guinea's timber exports (Bun et al. 2004). Regulations on the frequency of re-logging areas are being ignored (Nelson et al. 2014). Logging at higher altitudes has also been observed (Davis et al. 2018).Many areas of lowland forest in New Britain have been converted to oil palm plantations (Swartzendruber 1993, Stattersfield et al. 1998, Bishop and Jones 2001, Buchanan et al. 2008). Much of New Britain has been allocated as Special Agricultural Business Lease (SABL) areas, which would permit conversion to oil palm plantations. However, many of these areas appear to be unsuitable for oil palm, suggesting that they may be in place to facilitate commercial logging, under the pretext of oil palm development (Nelson et al. 2014, Bryan et al. 2015). Nevertheless, conversion to oil palm is likely to continue slowly on New Britain (Nelson et al. 2014).
Around 12% of forest cover in New Britain was lost between 1989 and 2000, with over 20% lost in the lowlands below 100 m (Buchanan et al. 2008). Since then, the rate of deforestation has apparently slowed (B. Beehler in litt. 2016), and around 2.2% of forest was lost, plus 5.2% degraded, across New Britain between 2002 and 2014 (Bryan et al. 2015). On New Ireland, most lowland forest was lost before 1989, and the area converted to oil palm has been much smaller (Davis et al. 2018). Other potential threats include hunting and road construction (Davis et al. 2018).
Conservation and Research Actions Underway
CITES Appendix II. Several bird surveys have taken place on New Britain and New Ireland (Lecroy & Peckover 1983, Beehler et al. 2001, Bishop & Jones 2001, Davis et al. 2018). No conservation measures are known to have been taken.
27-34 cm. Small, grey-and-white Accipiter. Adults dark grey above with rich chestnut hind collar and pale grey underparts. Juveniles have dark crowns, rufous upperparts with black mottling and pale buff underparts with strong dark streaks. Iris reported to be red, cere and legs pale yellow. Similar spp. Chestnut collar and short tail distinguish adult from similar Slaty-mantled Sparrowhawk A. luteoschistaceus. Grey Goshawk A. novaehollandiae adults are richer rufous below but variable juveniles may differ only in larger size and longer tail. Voice Unknown. Hints Perhaps most common in mountains, especially on New Ireland.
Text account compilers
Beehler, B.M., Bishop, K.D., Burrows, I., Diamond, J.M., Dutson, G., Bird, J., North, A., O'Brien, A., Derhé, M., Benstead, P., Mahood, S., Stattersfield, A. & Davies, R.
BirdLife International (2022) Species factsheet: Accipiter brachyurus. Downloaded from http://www.birdlife.org on 03/07/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 03/07/2022.