Christmas imperial pigeon (Ducula whartoni) With dark purple and green, iridescent plumage, the Christmas imperial pigeon can be seen perched conspicuously amongst the foliage of the Christmas Island rainforest. A mid-sized pigeon, with a distinctive bronzy green neck, the striking orange irises contrast sharply with a dark purplish grey head and a black bill. The underparts are dark sooty grey, with chestnut undertail-coverts, reddish brown legs and feet, and grey under the wings. In common with most pigeons, the sexes are very similar, but juveniles have a duller plumage, particularly around the chin and forehead, with darker and browner feathers on the underparts, and grey-brown legs.