Citron-crested Cockatoo Cacatua citrinocristata is split from Yellow-crested Cockatoo C. sulphurea (Clements 2007:130)

Summary: The southeastern Indonesian island of Sumba has another endemic species, the distinctively colored and now endangered Citron-crested Cockatoo.

Details: The original description of Cacatua citrinocristata was from a zoo specimen and was extremely brief, but citrinocristata was then and for many years subsequently considered a distinct species from C. sulphurea. It was however lumped with C. sulphurea (e.g., Peters 1937, Mayr 1944), and this treatment was generally followed until recently. Its morphology is distinctive in several respects (most of these enumerated in Collar and Marsden 2014), including in juvenile bill coloration (Schliebusch and Schliebusch 2001), despite the fact that its distribution is (at least historically) surrounded by much more homogeneous forms of C. sulphurea. Thus, WGAC and Clements et al. (2023) join Gill and Donsker (2012; v.3.1), Eaton et al. (2016), and HBW and BirdLife International (2022) in considering C. citrinocristata a full species.

English names: The English name Citron-crested Cockatoo for C. citrinocristata is familiar from long use elsewhere, and aligns with HBW and BirdLife International (2022) and Gill and Donsker (2012; v.3.1). We retain the familiar name Yellow-crested Cockatoo for the widespread though now generally rare C. sulphurea.