Rhyticeros plicatus

Range Biak, Numfor (M. Halaouate in litt. 2021), Yapen. Status Unclear. Presence on Biak is enigmatic. Neither of us has observed the species there despite numerous visits. However, several observers have recorded this very distinctive species. 15 August 1995: two, southern Biak (C. Eastwood, eBird checklist S 67701811); 30 October 2003: unknown number, Warafri area (S. Myers, eBird checklist S 70322018); Bengtsson (2007) saw several and noted they might be escapees; 26 September 2017: eight in the Oridek area (S. Lorenz, eBird checklist S 39398502); 26 June 2019: three in flight (T. Deininger, eBird checklist S 58672426); 30 June 2019: one (Goh Soon Kit, eBird checklist S 57804552). M. Halaouate (in litt. 2021) was informed that three hornbills had escaped from the Biak Birdpark and later saw two in flight; he also observed four on nearby Numfor in 2004. KDB found this species moderately common on nearby Yapen in 2016 ‒ 17. It appears that the birds on Biak are escapees from captivity, although over-water arrival from Numfor or Yapen is possible.