Cook Islands fruit-dove  (Ptilinopus rarotongensis)

Classified as Vulnerable (VU) on the IUCN Red List 2006 (1).

This small, beautifully coloured pigeon is found only on two small islands in the South Pacific Ocean. It has a bright magenta crown, against a pale grey head, chest and upper back. The Rarotonga subspecies also has a yellow belly with a bright magenta patch, whilst the Atiu subspecies has a pale greenish-yellow belly. The rest of its plumage is mostly green, apart from a yellow edging on the wing-feathers, and it has a pale green-brown bill (2) (3) (4). The male and female are similar in appearance, but juveniles are distinguished by the lack of red patches on its crown and belly (2). The calls of this bird, which are haunting coos, differ slightly between the two island populations.

Found only in the Cook Islands. There are two subspecies; Ptilinopus rarotongensis rarotongensis occurs on the island of Rarotonga, Ptilinopus rarotongensis goodwini is found only on Atiu Island (2).

On Rarotonga the Cook Islands fruit-dove occurs in hillside and upland forest, and on Atiu it can be found in the makatea forest, (forest that is growing on a raised coral limestone reef). It also often ventures onto agricultural land on both islands (5).

As its name suggests, the Cook Islands fruit-dove has a diet consisting primarily of fruit, such as the small figs produced by the banyan tree. However, it has also been observed pecking small insects from the trees and bushes where it feeds (2).

The Cook Islands fruit-dove is thought to breed around the period between July and September, when it generally lays one egg in a nest of loose twigs (4). In Rarotonga, a nest was observed for six weeks; both parents were seen incubating the egg and the nestling took its first flight 16 days after hatching (5).

As the Cook Islands fruit-dove occurs only on two small islands, it is vulnerable to threats such as introduced species, diseases and chance events, which could rapidly affect all the individuals in a population with devastating affects. It is reported that this bird is relatively common on both islands at present, but historically, the range of the Cook Islands fruit-dove was much larger; records show that it also used to be present on the islands of Aitutaki and Mauke. The loss of this bird from these islands shows its susceptibility to threats (3).

It is possible that introduced species may already be causing a slow decline of the Cook Islands fruit-dove. The black rat (Rattus rattus) is present on Rarotonga, where it preys on birds and their eggs and chicks. However, unlike the Eastern Polynesian flycatchers and lorikeets, there has been no marked decline in the fruit-dove since the black rat has become established, and therefore it is unlikely to be a major threat (6). The common myna, (a member of the starling family), which was introduced to the Cook Islands to control insect numbers in agricultural areas, prevents the fruit-dove from nesting in horticultural areas, where the myna is common and highly territorial (6).

Whilst there are no known conservation measures in place aimed specifically at the Cook Islands fruit-dove, it probably benefits from conservation actions carried out for the endangered Rarotonga flycatcher (Pomarea dimidiata), such as a rat control programme. To prevent the Cook Island fruit-dove disappearing from more of its range, it is important to monitor populations carefully, conduct research to determine their immediate conservation requirements, and take measures to prevent the introduction of any more exotic species (2) (3).

View information on this species at the UNEP World Conservation Monitoring Centre.

For further information on this species see the Cook Islands Biodiversity Database:
http://cookislands.bishopmuseum.org/species.asp?id=8736

For more information on this and other bird species please see:

• BirdLife International:
  http://www.birdlife.org