Restricted to just a single island, the population of the Christmas imperial-pigeon is extremely small, with around 1,000 breeding individuals (3). Due to the destruction of a third of its habitat from phosphorous mining, and the introduction of the invasive ant species, Anoploepis gracilipes, which preys on nestlings and farms scale insects that cause canopy die-back, the Christmas imperial-pigeon received a Critically Endangered status on the IUCN Red List of Threatened Species in 2000 (4). However, the successful control of A. gracilipes using toxic bait between 2000 and 2006, eradicated the ant from around 95 percent of its former range, allowing the Christmas imperial-pigeon population to stabilise. The species also benefited from the introduction of the Japanese cherry, as it grows in areas that were formerly mined, thus increasing the area of suitable habitat (2) (3). Consequently, the species’ status has since been downgraded to Near Threatened (3).
Unfortunately, the A. gracilipes population has now partially recovered, and continues to threaten the Christmas imperial-pigeon, while plans for further mining have been proposed, within the species’ range (3). Other threats that may have an impact on the population include hunting and predation by introduced feral cats, while its restricted distribution makes it vulnerable to the effects of chance natural events, such as disease and drought (3) (6). The introduced population on the Cocos-Keeling Islands is believed to have gone extinct around 1900, due to hunting and a lack of food sources (4).