Ducula spilorrhoa (G. R. Gray, 1858)

Bishop, K. David, 2023, The avifauna of Biak Island, Papua, Indonesia with comments on status, conservation, natural history and taxonomy, Bulletin of the British Ornithologists’ Club 143 (1), pp. 3-62 : 21

TORRESIAN IMPERIAL PIGEON Ducula spilorrhoa #

Local name Man Dun (Sansudi, Kuneff).

Range Biak, Supiori, Owi, Mios Num, Yapen and many small islets.

Taxonomy Formerly considered a race of Pied Imperial Pigeon D. melanura but split by del Hoyo & Collar (2014) and Beehler & Pratt (2016). Christidis & Boles (2008) highlighted the complexity of issues related to the various populations in this species group (Pied Imperial Pigeon D. bicolor, Torresian Imperial Pigeon D. spilorrhoa , Silver-tipped Imperial Pigeon D. luctuosa and Yellowish Imperial Pigeon D. subflavescens ), which clearly merits re-analysis using molecular data (Beehler & Pratt 2016).

Status Resident. Obtained by four collectors including Ripley who found it common in mangroves and up to 500 m. Infrequently seen by subsequent visitors. 29 August 2015: KDB saw a flock of five in flight over forest west of Biak town and 13 perched in tall mangrove forest at Tanjung Barai, at the eastern tip of Biak . 8 December 2016: KDB saw 20 flying into the tsunami swamp ; 10 November 2017: three (A. Walker, eBird checklist S46415319) and 5 August 2018 ten (S. Lorenz, eBird checklist S47661085) at the latter site. 13 January 1994: five on Owi (P. Gregory in litt. 2000); July 2012 small numbers on a rocky islet off southern Biak ( van Beirs 2012 ) .

Breeding Ripley found nests with eggs in mangroves in mid December ( Mayr & Meyer de Schauensee 1939). 11 January 1997: a young bird was shown to SvB at Marauw. Mitchell (1989) noted the species nesting in October‒March on Kumbur and Nutabari in the Auri archipelago, south-east Teluk Cenderawasih. Recent observations in mangroves during December‒January may pertain to breeders like Ripley’s observations. Largely a seasonal migrant from north-east Australia (Beehler & Pratt 2016), but breeds in the Middle Sepik and on islands off south-east New Guinea (Coates 1985) . These may be the only breeding records for Indonesian New Guinea.