Justification of Red List Category
This little-known species is classified as Vulnerable on the basis of very small island subpopulations which are suspected to be declining through forest loss. However, it has been seen so infrequently that any population estimates are largely conjecture, and it may qualify for a higher threat category.
The population is estimated to number 250-999 mature individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 375-1,499 individuals in total, rounded here to 350-1,500 individuals.
An on-going moderate population decline is suspected on the basis of rates of habitat loss, given that this species is definitely rare in degraded forest and therefore must be suffering a continuing decline as forest continues to be logged and otherwise degraded across the lowlands of its range.
Accipiter imitator is endemic to Bougainville, Papua New Guinea, and Choiseul and Santa Isabel, Solomon Islands. It is rare but may be overlooked because of its unobtrusive forest habits, and it perhaps lacks a distinctive call. It is known from just one specimen from Bougainville and a handful from both Choiseul and Isabel (Schodde 1977). During many weeks of fieldwork on all three islands in the 1980s and 1990s, it was seen only once on Bougainville (Hadden 1981) and there was a series of records from Tirotonga village on Isabel. One specimen was also taken there, but some of the other field records and local reports, including those of all-black individuals, have been queried (Webb 1992, 1995, Debus 1995). A recent visit to Bougainville led Hadden (2008) to suspect that the species may be reasonably common in the forest interior throughout the island, given the mist-net capture of two individuals in relatively few net-hours. The species was recorded at one site on Choiseul in 2014 (Boseto and Pikacha 2016). Population numbers and trends are difficult to assess from so few recent records, but the species is clearly rare and appears to have declined, on Choiseul at least (K. D. Bishop in litt. 1994, D. Gibbs in litt. 1994, G. Dutson pers. obs. 1998).
This species has been collected and sighted in lowland forest or forest edge to at least 400 m and, possibly, 1,000 m (Webb 1992, 1995, Debus 1995, Dutson 2011). One was seen feeding on a Chestnut-bellied Monarch Monarcha castaneiventris (Webb 1997). Its ecology is poorly known and its niche separation from A. albogularis is unknown, but its shorter wings and tail and longer legs suggest that it is better adapted to interior forest (Schodde 1977).
As a lowland and hill species with almost all records from old-growth forest, it is likely to be threatened by forest loss and degradation. Industrial logging continues on Choiseul and Santa Isabale (G. Dutson in litt. 2016) and logging may become a problem on Bougainville when the island opens up to development. On all islands, there is ongoing but limited habitat loss to forest clearance for subsistence gardens. It possibly suffers from competition with A. albogularis, especially in degraded forest.
Conservation Actions Underway
CITES Appendix II. No conservation measures are known to have been taken.
28-33 cm. Small, pied hawk with black- and white-throated and possibly all-black morphs. Adult jet-black above, the throat and breast either black or white. Reddish-brown iris. Immatures mottled rufous with fine black barring on underparts. Similar spp. White-throated birds very similar to Pied Goshawk A. albogularis which is dark grey above, often with rufous collar, paler grey undersides to wing and tail and orange iris. Immature has dark streaks and drop-marks on the underparts. Voice Wailing reo. Possibly also a chatter. Hints Check all pied hawks on the three islands.
Text account compilers
Benstead, P., Derhé, M., Dutson, G., Mahood, S., O'Brien, A., Stattersfield, A. & North, A.
Bishop, K., Dutson, G. & Gibbs, D.
BirdLife International (2019) Species factsheet: Accipiter imitator. Downloaded from http://www.birdlife.org on 17/11/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 17/11/2019.