Rarest lorikeet

The rarest species of lorikeet is the New Caledonian lorikeet Charmosyna diadema, a small bright-green lorikeet confined entirely to the island of New Caledonia off Australia. The last confirmed record of this species was in 1913, but there have been a number of unconfirmed sightings by eyewitnesses deemed reliable since then, until at least as recently as 1976. Consequently, the IUCN considers it not implausible that this species may still exist in some of the island's famously wild, relatively inaccessible areas of highland rainforest, and continues to categorize it as Critically Endangered rather than as Extinct. No captive specimens exist.

This species is known only from two preserved female skins, one of which is now lost and the other is in Paris's Natural History Museum. The appearance of the male form is unknown, but judging from that of other, comparable lorikeet species, it probably exhibited (or exhibits) more areas of red than in the predominantly green female. The juvenile form's appearance is also unknown, but was probably similar to a dull-coloured adult female in terms of plumage colouration.