Justification
This species is restricted to one small island location. It is predicted to undergo a rapid decline of a magnitude greater than 80% in 12 years (three generations), due to the introduction and recent spread of a species of ant. It has therefore been upgraded to Critical.

Threats
About one third of the species's preferred plateau forest was cleared for phosphate mining before clearance ceased in 1987. This loss has been partly offset by the introduction of M. calabura, which flourishes on many former mine fields and other disturbed areas, and provides a rich food source for much of the year. Illegal hunting continued after prohibition in 1977, but is now less prevalent. The failure of the introduction to Cocos-Keeling Islands has been attributed to hunting and/or lack of suitable food-trees. The most serious threat is the rapid spread of the introduced yellow crazy ant Anoplolepis gracilipes. This ant is likely to prey directly on nestlings, and may also alter the island ecology as it kills red crab Gecaroidea natalis, the dominant life-form, and farms scale insects which damage the trees.

Conservation
A national park was established in 1980, and has since been extended. Contingency plans are being developed to establish a captive population on mainland Australia . A control programme for A. gracilipes has been initiated.

Targets
*Refine techniques for the control of A. gracilipes. *Control the abundance and spread of A. gracilipes. *Establish a captive population of D. whartoni with the aim of reintroduction once control has been achieved.