Justification of Red List Category
This species is considered Vulnerable on the basis of a small estimated population which is suspected to have declined rapidly through rapid lowland forest loss, driven partly by development of oil palm plantations. However, rates of forest loss and degradation have slowed in recent years.
The population is estimated to number 10,000-19,999 individuals based on an assessment of known records, descriptions of abundance and range size (Buchanan et al. 2008, Davis et al. in prep.). 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 equates to about 6,000-15,000 mature individuals.
Buchanan et al. (2008) calculated the rate of forest loss within the species's range on New Britain as about 19% over three generations (30 years). Less detailed analysis is available for later years but about 2.2% of forest was lost plus 5.2% degraded across New Britain between 2002 and 2014 (Bryan and Shearman 2015). It is inferred that forest loss and degradation has slowed and the species’s rate of decline is now estimated at 10-19% over over three generations (30 years).
Henicopernis infuscatus is a little-known endemic of New Britain (including Lolobau) in Papua New Guinea. As a large raptor, it is believed to occur at low population densities and it appears to be much less common than the allospecific New Guinea Long-tailed Buzzard H. longicauda (B. Finch in litt. 1994, K. D. Bishop in litt. 1994, G. Dutson pers. obs. 1997-1998, P. Gregory in litt. 1999). However, it is an inconspicuous forest species which is probably widespread and is likely to be under-recorded (Dutson 2011).
It is usually recorded gliding over primary hill forest to a maximum of 1,300 m (K. D. Bishop in litt. 1994). There are few records from logged or otherwise degraded forest, but its habitat requirements are poorly known (Dutson 2011). Its feeding ecology may be similar to that of H. longicauda which hunts above or within the canopy for arthropods, lizards, birds and birds' eggs (Coates 1985).
Nearly all lowland and hill forests on gentle gradients on New Britain have been logged or are under logging concessions, and large areas have been converted to oil-palm plantations (Buchanan et al. 2008). However, much of this species's habitat is on steep slopes and montane forest which is not suitable for logging (Clay 1994, G. Dutson pers. obs. 1997-1998) and conversion to oil palm plantations has slowed as few remaining areas suitable for new plantations. Forest is also being slowly degraded and lost to subsistence gardens by the growing local population. These striking birds are likely to be shot opportunistically as trophies and for meat (K. D. Bishop in litt. 1994). Hunting has rendered H. longicauda scarce in some areas of New Guinea (Coates 1985).
Conservation Actions Underway
CITES Appendix II. No conservation measures are known.
50 cm. Large, heavily barred, forest raptor. Almost black with conspicuous white bands on flight and tail feathers. Usually seen in flight when long tail and long wings with bulging secondaries and broad wing-tips are distinctive. Similar spp. Pacific Baza Aviceda subcristata is smaller and much paler. Voice Piped series of c.12 accelerating, upslurred notes. Hints Usually seen from vantage points overlooking hill or montane forest.
Text account compilers
Derhé, M., Dutson, G., Mahood, S., O'Brien, A. & Stattersfield, A.
Beehler, B., Bishop, K., Dutson, G., Finch, D., Gregory, P., Pilgrim, J. & Wilkinson, R.
BirdLife International (2019) Species factsheet: Henicopernis infuscatus. Downloaded from http://www.birdlife.org on 24/08/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 24/08/2019.