Acrocephalus longirostris (Gmelin)

Moorea Reed-Warbler (Acrocephalus longirostris)  

The Tahiti Reed-Warbler (Acrocephalus caffer (Sparrman)) was described in 1786 as Sitta caffra, quasi as a nuthatch coming from southern Africa. This shows how much scientists in the 18th century understood of biogeography, biology, and taxonomy …!  

This species is now the sole member of its genus leftover in the Society Islands, but in former times there were at least four distinct forms inhabiting at least four of the islands in the archipelago. 


According to DNA analyses made in 2008, it is now known that the four known reed warbler forms formerly found on the Society Islands are/were not conspecific but evolved from three separate colonization events.  

Thus, the Moorea Reed-Warbler, but also the Raiatea Reed-Warbler (Acrocephalus musae (J. R. Forster)), are now regarded as full species. [1]  


The Moorea Reed-Warbler was described in 1789 (as a thrush, by the way).  

The species reached a size of about 19 cm and was superficially quite similar to the other Society Islands reed-warbler species but differed from them by its conspicuously pale outher tail feathers (unlike in the depiction below).  

The last approved record dates from 1981, however there appears to be a recent sighting made sometimes in 1998 or 1999 including a photo that, given the color of the tail feathers, almost certainly depicts this species. It is nevertheless now regarded as most likely extinct.



[1] Alice Cibois; Jean-Claude Thibault; Eric Pasquet: Systematics of the extinct reed warblers Acrocephalus of the Society Islands of eastern Polynesia. Ibis 150: 365–376. 2008  


Depiction: William Ellis; between 1776 and 1778

(public domain)


edited: 21.01.2019