Roland Seitre / Goliath Imperial Pigeon (Ducula goliath) feeding on fruit, Touaourou mission,Yate, South Province, New Caledonia.

David Tipling / Island imperial pigeon (Ducula pistrinaria) perched in tree. Solomon Islands.

David Tipling / Red-knobbed imperial pigeon (Ducula rubricera) perched in tree. Solomon Islands.

Staffan Widstrand / Spice imperial pigeon (Ducula myristicivora) Raja Ampat, Western Papua, Indonesian New Guinea.

Staffan Widstrand / Spice imperial pigeon (Ducula myristicivora) Raja Ampat, Western Papua, Indonesian New Guinea

Staffan Widstrand / Spice imperial pigeon (Ducula myristicivora) two perched, Raja Ampat, Western Papua, Indonesian New Guinea

Staffan Widstrand / Spice imperial pigeon (Ducula myristicivora) two perched, Raja Ampat, Western Papua, Indonesian New Guinea

Eric Sohn Joo Tan/ BIA / Green Imperial-Pigeon (Ducula aenea), Udawalawe National Park, Sri Lanka

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.

Frederique Olivier / Island imperial / Grey fruit pigeon (Ducula pistrinaria) perched in tree, Kicha Island, Solomon Islands.

Roland Seitre / Goliath Imperial Pigeon (Ducula goliath) feeding on fruit, Touaourou mission,Yate, South Province, New Caledonia.

Roland Seitre / Goliath Imperial Pigeon (Ducula goliath) feeding on fruit, Touaourou mission,Yate, South Province, New Caledonia.

Roland Seitre / Goliath Imperial Pigeon (Ducula goliath) on nest, captive, Parc zoologique et forestier / Zoological and Forest Park, Noumea, South Province, New Caledonia

Roland Seitre / Goliath Imperial Pigeon (Ducula goliath) portrait, captive, Parc zoologique et forestier / Zoological and Forest Park, Noumea, South Province, New Caledonia

Roland Seitre / Goliath Imperial Pigeon (Ducula goliath) Touaourou mission,Yate, South Province, New Caledonia.

Roland Seitre / Goliath Imperial Pigeon (Ducula goliath) Touaourou mission,Yate, South Province, New Caledonia.

Roland Seitre / Goliath Imperial Pigeon (Ducula goliath) on nest, captive, Parc zoologique et forestier / Zoological and Forest Park, Noumea, South Province, New Caledonia

Roland Seitre / Goliath Imperial Pigeon(Ducula goliath) feeding on fruit, Touaourou mission,Yate, South Province, New Caledonia.

Roland Seitre / Goliath Imperial Pigeon (Ducula goliath) on fruiting tree, Touaourou mission,Yate, South Province, New Caledonia.

Roland Seitre / Goliath Imperial Pigeon (Ducula goliath) perched, Mount Khogi, Dumbea, Noumea, South Province, New Caledonia.

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

Sue Flood / Pacific Imperial pigeon (Ducula pacifica) perched, Atiu Island, Cook Islands, South Pacific, November

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

Brent Stephenson / Red-knobbed Imperial Pigeon (Ducula rubricera) perched on a mossy branch. Captive. Kavieng, New Ireland, New Guinea, April.

Brent Stephenson / Marquesas Imperial / Nuku Hiva Pigeon (Ducula galeata) feeding on fruits in the canopy. Hatiheu, Nuku Hiva, Marquesas, French Polynesia, November.

Konrad Wothe / Torresian Imperial-Pigeon (Ducula spilorrhoa) pair, Atherton Tableland, Queensland, Australia

Konrad Wothe / Torresian Imperial-Pigeon (Ducula spilorrhoa), Atherton Tableland, Queensland, Australia

Tim Laman / Pinon's imperial pigeon (Ducula pinon) on branch, Batanta Island, Papua, Indonesia

Thomas Marent / Pinon Imperial-Pigeon (Ducula pinon), Papua New Guinea

Thomas Marent / Pinon Imperial-Pigeon (Ducula pinon) pair, Papua New Guinea

Tim Laman / Marquesan Imperial Pigeon (Ducula galeata) Nuku Hiva Island, Marquesas Islands, French Polynesia. IUCN Red List: Critically Endangered

Steven David Miller / Torresian imperial pigeon on nest with chick {Ducula spilorrhoa} Queensland Australia

Pete Oxford / Pinon's imperial pigeons {Ducula pinon} occurs Indonesia

Anup Shah / Profile portrait of Pinon's imperial pigeon {Ducula pinon} native to Papua New Guinea

Tim Laman / Marquesan Imperial Pigeon (Ducula galeata) Nuku Hiva Island, Marquesas Islands, French Polynesia. IUCN Red List: Critically Endangered

Tim Laman / Peale's Imperial / Barking Pigeon (Ducula latrans) in rainforest of Taveuni Island, Fiji. Endemic to Fiji.

Joel Sartore / Photo Ark / Collared imperial pigeon (Ducula mullerii) portrait, Walsrode Bird Park, Germany. Captive, occurs in New Guinea.

Joel Sartore / Photo Ark / Collared imperial pigeon (Ducula mullerii) head portrait, Walsrode Bird Park, Germany. Captive, occurs in New Guinea.

Tom Vierus / Barking imperial pigeon (Ducula latrans) perched in tree, Colo-i-Suva Forest park, near Suva, Viti Levu, Fiji.

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 / Collared imperial-pigeon (Ducula mullerii) perched on branch, New Guinea. Captive.

Roland Seitre / Pinon's imperial pigeon (Ducula pinon) perched on branch, New Guinea. Captive.

Roland Seitre / Two Pinon's imperial pigeons (Ducula pinon) perched on branch, New Guinea. Captive.

Roland Seitre / Chestnut-bellied pigeon (Ducula goliath) hanging upside down in tree, feeding on berries, Touaourou, New Caledonia.

Roland Seitre / Chestnut-bellied pigeon (Ducula goliath) hanging upside down in tree, feeding on berries, Touaourou, New Caledonia.

Roland Seitre / Chestnut-bellied pigeon (Ducula goliat) perched on branch, Touaourou, New Caledonia.

Roland Seitre / Chestnut-bellied pigeon (Ducula goliat) head portrait, Parc zoologique et forestier Noumea, New Caledonia. Captive.

Roland Seitre / Chestnut-bellied pigeon (Ducula goliat) head portrait, Parc zoologique et forestier Noumea, New Caledonia. Captive.

Roland Seitre / Chestnut-bellied pigeon (Ducula goliath) perched in tree among yellow berries, Touaourou, New Caledonia.

Roland Seitre / Chestnut-bellied pigeon (Ducula goliath) perched in tree among yellow berries, Touaourou, New Caledonia.

Roland Seitre / Chestnut-bellied pigeon (Ducula goliath) perched in tree among yellow berries, Touaourou, New Caledonia.

Roland Seitre / Chestnut-bellied pigeon (Ducula goliath) perched in tree among orange berries, Touaourou, New Caledonia.

Roland Seitre / Chestnut-bellied pigeon (Ducula goliath) perched in tree feeding on berries, Touaourou, New Caledonia.

Roland Seitre / Island imperial pigeon (Ducula pistrinaria) perched on branch, stretching its wings, Hong-Kong Gardens, Hong Kong. Captive, occurs in New Guinea.

Roland Seitre / Island imperial pigeon (Ducula pistrinaria) perched on branch, Hong-Kong Gardens, Hong Kong. Captive, occurs in New Guinea.

Roland Seitre / Two Rufous-bellied fruit pigeons (Ducula rufigaster) perched on branch, Hong-Kong Gardens, Hong Kong. Captive, occurs in New Guinea.

Roland Seitre / Red-knobbed imperial-pigeon (Ducula rubricera) portrait, Solomon Islands. Captive.

Roland Seitre / Two Red-knobbed imperial-pigeons (Ducula rubricera) portrait, Solomon Islands. Captive.

Roland Seitre / Two Red-knobbed imperial-pigeons (Ducula rubricera) perched in the rain, one flapping its wings, Solomon Islands. Captive.

Roland Seitre / Red-knobbed imperial-pigeon (Ducula rubricera) shaking rainwater from its wings, Solomon Islands. Captive.

Roland Seitre / Two Blue-tailed imperial pigeons (Ducula concinna) perched on branch, New Guinea. Captive.

Roland Seitre / Blue-tailed imperial pigeon (Ducula concinna) perched on branch, New Guinea. Captive.

Roland Seitre / Two Indian green imperial-pigeons (Ducula aenea sylvatica) perched on branch, China. Captive.

Roland Seitre / Green imperial-pigeon (Ducula aenea aenea) perched on branch, Sulawesi, Indonesia. Captive.

Roland Seitre / Two Green imperial-pigeons (Ducula aenea aenea) perched on branch, Sulawesi, Indonesia. Captive.

Roland Seitre / Two Green imperial-pigeons (Ducula aenea aenea) perched on branch, Sulawesi, Indonesia. Captive.

Roland Seitre / Green and white zone-tailed pigeon (Ducula forsteni) perched on branch, Sulawesi, Indonesia. Captive.

Roland Seitre / Green and white zone-tailed pigeon (Ducula forsteni) perched on branch, Sulawesi, Indonesia. Captive.

Roland Seitre / Yellowish imperial pigeon (Ducula subflavescens) perched in tree, Bismarck Archipelago. Captive.

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

Roland Seitre / Two Dark-backed Imperial pigeons (Ducula lacernulata) perched on branch, Java, Indonesia. Captive.

Roland Seitre / Dark-backed Imperial pigeon (Ducula lacernulata) perched on branch, Java, Indonesia. Captive.

Roland Seitre / Banded imperial pigeon (Ducula zoeae) perched in tree, New Guinea. Captive.

Roland Seitre / Collared Imperial pigeon (Ducula mullerii) perched on branch, New Guinea. Captive.

Roland Seitre / Four Christmas Island imperial pigeons (Ducula whartoni) drinking from puddle, Christmas Island, Australia.

Roland Seitre / Christmas Island imperial pigeon (Ducula whartoni) perched in tree, Christmas Island, Australia.

Roland Seitre / Christmas Island imperial pigeon (Ducula whartoni) perched in tree feeding on fruit, Christmas Island, Australia.

Roland Seitre / Island imperial pigeon (Ducula pistrinaria) perched on branch, New Guinea. Captive.

Roland Seitre / Rufous-bellied fruit pigeon (Ducula rufigaster) perched on branch, New Guinea. Captive.

Roland Seitre / Marquesan imperial pigeon (Ducula galeata) perched on branch, Ua Huka, Marquesas Islands. Endangered.

Roland Seitre / Makatea pigeon (Ducula aurorae aurorae) perched in tree, Makatea, Tuamotus, French Polynesia. Endangered.

Roland Seitre / Blue-tailed imperial pigeon (Ducula concinna) perched in tree, New Guinea. Captive.

Roland Seitre / Blue-tailed imperial pigeon (Ducula concinna) perched in tree, New Guinea. Captive.

Roland Seitre / White-eyed imperial pigeon (Ducula perspicillata) perched in tree, calling, Moluccas, Indonesia. Captive.

Roland Seitre / Two Grey-necked fruit pigeons (Ducula carola) perched on branch, Philippines. Captive.

Roland Seitre / Grey-necked fruit pigeon (Ducula carola) perched on branch, Philippines. Captive.

Roland Seitre / Pinon Imperial-Pigeon (Ducula pinon), native to Papua New Guinea

Bruce Thomson / Two Christmas Island imperial pigeon (Ducula whartoni) perching in treetops, Christmas Island, Australia.

Bruce Thomson / Christmas Island imperial pigeon (Ducula whartoni) perching on a branch, Christmas Island, 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...