Juergen & Christine Sohns / Pied Imperial-Pigeon (Ducula bicolor) pair, Singapore Zoo, Singapore

Juergen & Christine Sohns / Pied Imperial-Pigeon (Ducula bicolor), Singapore Zoo, Singapore

Roger Powell / Pied Imperial-pigeon (Ducula bicolor) looking for food amongst unripe Palm fruit. Mary River, Northern Territory, Australia.

Daniel Heuclin / Pied Imperial-pigeon / Nutmeg pigeon (Ducula bicolor) preening, captive, From Nicobar Islands to North Australia.

Daniel Heuclin / Pied Imperial-pigeon / Nutmeg pigeon (Ducula bicolor) preening, captive, From Nicobar Islands to North Australia.

Tim Fitzharris / Pied Imperial-Pigeon (Ducula bicolor), Jurong Bird Park, Singapore

Martin Willis / Pied Imperial-Pigeon (Ducula bicolor) on nest, Townsville, Queensland, Australia

Martin Willis / Pied Imperial-Pigeon (Ducula bicolor) at stick nest, Townsville, Queensland, Australia

Roland Seitre / Celebes pied imperial pigeon (Ducula luctuosa) perched on wooden stump, looking back, Sulawesi, Indonesia.

Roland Seitre / Pied imperial pigeon (Ducula bicolor) perched on branch, Thailand. Captive.

Roland Seitre / Australian pied imperial pigeon (Ducula spilorrhoa) perched in tree, Australia

Bruce Thomson / Pied imperial / Torresian pigeon (Ducula bicolor) flock on long daily commute over the sea from the mainland to breeding grounds in mangroves off Great Barrier Reef Islands, Low Isles, Coral Sea off P...