White-winged Sandpiper
The story
Whether there was one extinct species of sandpiper occupying the Pacific islands of Tahiti and Moorea or whether there were, in fact, two remains something of an enigma. The naturalists who actually saw the birds in life and handled fresh specimens were convinced that there was only one, but more recent commentators have produced reasonable arguments that there were two: a form from Tahiti (leucoptera) with a more sandy-coloured breast; and another from Moorea (ellisi), with more reddish underparts.
No definitive solution to this problem is possible. Although there were once several specimens in existence, only one (an example now in Leiden) survives today. This is one of the more sandy-coloured individuals. The species was only ever seen by naturalists who sailed with Cook and one of them, Georg Forster, painted a picture of a Moorea bird showing the more reddish breast. It is on the basis of this painting that the form ellisi is named. Clearly the birds – whether there was once species or two – became extinct at an early date. Other than the fact that Forster found it close to small brooks, nothing is known of it in life.
Authority and reference
Gmelin, 1789 || Syst. Nat. 1(2): 678