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).