Martin Willis / Sulphur-crested Cockatoo (Cacatua galerita) displaying with crest erected, Brisbane, Queensland, Australia

Martin Willis / Sulphur-crested Cockatoo (Cacatua galerita) flying, Magnetic Island, Queensland, Australia

Jan Wegener / Sulphur-crested Cockatoo (Cacatua galerita), Victoria, Australia

WILLIAM OSBORN / Sulphur crested cockatoo {Cacatua galerita} Queensland, Australia

WILLIAM OSBORN / Sulphur crested cockatoo {Cacatua galerita} feeding from foot, QLD, Australia

Gerry Ellis / Sulphur-crested Cockatoo (Cacatua galerita) perching on branch, New Guinea

Steven David Miller / Sulphur-crested cockatoo (Cacatua galerita) male perched on tree stump, displaying through bobbing, throwing out crest and screeching. Grampians National Park, Victoria, Australia. March.

Steven David Miller / Sulphur-crested cockatoo (Cacatua galerita) male displaying, perched on tree stump. Grampians National Park, Victoria, Australia. March.

Steven David Miller / Sulphur-crested cockatoo (Cacatua galerita), three perched on branch. Campground, Grampians National Park, Victoria, Australia. March.

Doug Gimesy / Portrait of a wild Sulphur-crested cockatoo (Cacatua galerita) Skenes Creek, Victoria, Australia.

Doug Gimesy / Portrait of a wild Sulphur-crested cockatoo (Cacatua galerita) Skenes Creek, Victoria, Australia.

Doug Gimesy / Portrait of a Sulphur-crested cockatoo (Cacatua galerita) perched on a TV antenna. Skenes Creek, Victoria, Australia. March.

Doug Gimesy / Portrait of a wild Sulphur-crested cockatoo (Cacatua galerita) Skenes Creek, Victoria, Australia.

Steven David Miller / Sulphur-crested cockatoo (Cacatua galerita) feeding on seedpods in Flax wattle (Acacia linifolia) tree. Lane Cove National Park, Sydney, New South Wales, Australia.

Steven David Miller / Sulphur-crested cockatoo (Cacatua galerita) feeding on Spider flower (Grevillea sp) seed pods whilst perched. Lane Cove National Park, Sydney, New South Wales, Australia.

Juergen & Christine Sohns / Sulphur-crested Cockatoo (Cacatua galerita), Long Beach, New South Wales, Australia

Juergen & Christine Sohns / Sulphur-crested Cockatoo (Cacatua galerita) feeding, Long Beach, New South Wales, Australia

Juergen & Christine Sohns / Sulphur-crested Cockatoo (Cacatua galerita) feeding, Long Beach, New South Wales, Australia

Lynn M. Stone / Sulphur-crested cockatoo (Cacatua galerita) perched on branch with palm leaves in background. Captive.

Ernie Janes / Sulphur-crested cockatoo (Cacatua galerita) Hobart Botanical Garden, Tasmania, Australia.

Ernie Janes / Sulphur-crested cockatoo (Cacatua galerita) flock in flight over Hobart Botanical Garden Tasmania, Australia.

Staffan Widstrand / Dead Sulphur-crested cockatoo (Cacatua galerita) with ants crawling all over it. Lowland rainforest, Karawawi River, Kumawa Peninsula, mainland New Guinea, Western Papua

Ingo Arndt / Sulphur crested cockatoo (Cacatua galerita) Kakadu National Park, Northern Territory, Australia, December

Jiri Lochman / Sulphur-creasted cockatoo (Cacatua galerita) pair, one displaying to another, Wollemi National Park, Greater Blue Mountains UNESCO Natural World Heritage Site, New South Wales.

Juergen & Christine Sohns / Sulphur-crested Cockatoo (Cacatua galerita) displaying, Singapore Zoo, Singapore

Juergen & Christine Sohns / Sulphur-crested Cockatoo (Cacatua galerita), Singapore Zoo, Singapore

Roger Powell / Sulphur-crested cockatoo (Cacatua galerita) looking down from a fir tree, Halls Gap, Victoria, Australia.

Roger Powell / Sulphur-crested cockatoo (Cacatua galerita) resting in a eucalyptus tree, Halls Gap, Victoria, Australia.

Roger Powell / Young woman feeding Sulphur-crested cockatoos (Cacatua galerita) in a park, Sherbourne, Victoria, Australia.

Tim Laman / Sulphur-crested cockatoo (Cacatua galerita) in swampy area of rainforest, New Guinea, June.

Juergen Freund / Sulphur-crested cockatoo (Cacatua galerita) flock roosting, Atherton Tablelands, Queensland,Australia.

Juergen Freund / Huge flock of Sulphur-crested Cockatoo (Cacatua galerita) and Straw-necked Ibis (Threskiornis spinicollis) flying after eating / digging peanuts from the newly ploughed fields. Atherton Tablelands, Qu...

Juergen Freund / Huge flock of Sulphur-crested Cockatoo (Cacatua galerita) flying after eating / digging peanuts from the newly ploughed fields. Atherton Tablelands, Queensland,Australia.

Juergen Freund / Huge flock of Sulphur-crested cockatoo eating (Cacatua galerita) Atherton Tablelands, Queensland,Australia.

Juergen Freund / Huge flock of Sulphur-crested cockatoo (Cacatua galerita) eating / digging peanuts from the newly ploughed fields. Atherton Tablelands, Queensland,Australia.

Juergen & Christine Sohns / Sulphur-crested Cockatoo (Cacatua galerita), South Australia, Australia

Juergen Freund / Sulphur-crested cockatoo (Cacatua galerita) flock in flight, Atherton Tablelands, Queensland, Australia.

Juergen Freund / Sulphur-crested cockatoo (Cacatua galerita) flock in flight, Atherton Tablelands, Queensland, Australia.

Cyril Ruoso / Bird show with trained Blue-and-yellow macaw (Ara ararauna) and Sulfur crested cockatoo (Cacatua galerita) riding bicycles. Singapore Bird Park.

D. Parer & E. Parer-Cook / Sulphur-crested Cockatoo (Cacatua galerita) pair, Lockhart River, Queensland, Australia

Martin Willis / Sulphur-crested Cockatoo (Cacatua galerita) displaying with crest erected, Magnetic Island, Queensland, Australia

Greg Oakley / Sulphur-crested Cockatoo (Cacatua galerita) displaying, Victoria, Australia

Dave Watts / Sulphur-crested Cockatoo (Cacatua galerita) flock gathering in seaside town, Lorne, Victoria, Australia, November 2012.

Rob Drummond / Sulphur-crested Cockatoo (Cacatua galerita), Victoria, Australia

Jan Wegener / Sulphur-crested Cockatoo (Cacatua galerita) pair preening, Victoria, Australia

Jan Wegener / Sulphur-crested Cockatoo (Cacatua galerita), Victoria, Australia

Jan Wegener / Sulphur-crested Cockatoo (Cacatua galerita), Victoria, Australia

Jan Wegener / Sulphur-crested Cockatoo (Cacatua galerita), Victoria, Australia

Jan Wegener / Sulphur-crested Cockatoo (Cacatua galerita) pair, Victoria, Australia

Cyril Ruoso / Sulphur-crested Cockatoo (Cacatua galerita) drinking water from a spigot, Australia

David Tipling / Sulphur-crested Cockatoo (Cacatua galerita) silhouetted in early morning, Miles, Queensland, Australia

David Tipling / Sulphur-crested Cockatoo (Cacatua galerita) hanging upside down from branch, Miles, Queensland, Australia

David Tipling / Sulphur-crested Cockatoo (Cacatua galerita) feeding on figs, Queensland, Australia

Steven David Miller / Sulphur-crested cockatoo (Cacatua galerita) perched on branch, Grampians National Park, Victoria, Australia, May

Steven David Miller / Sulphur-crested cockatoo (Cacatua galerita) perched on branch, Grampians National Park, Victoria, Australia, May

Steven David Miller / Sulphur-crested cockatoo (Cacatua galerita) perched on branch, Grampians National Park, Victoria, Australia, May

Dave Watts / Sulphur-crested cockatoo (Cacatua galerita) perched, Australian Capital Territory, Australia, December

Dave Watts / Sulphur-crested cockatoo (Cacatua galerita) perched, Australian Capital Territory, Australia, December

Dave Watts / Sulphur-crested cockatoo (Cacatua galerita) perched, Australian Capital Territory, Australia, December

Dave Watts / Sulphur-crested cockatoo (Cacatua galerita) perched with feather fluffed up, Australian Capital Territory, Australia, December

Kevin Schafer / Aerial view of Sulphur-crested Cockatoos (Cacatua galerita) in flight over tropical rainforest canopy, Atherton Tablelands, Queensland, Australia, November

Ernie Janes / Pet Sulphur crested cockatoo (Cacatua galerita) looking at itself in mirror with crest raised, UK

Ernie Janes / Pet Sulphur crested cockatoo (Cacatua galerita) perched with crest raised, UK

Ernie Janes / Pet Sulphur crested cockatoo (Cacatua galerita) with crest raised, UK

Ernie Janes / Pet Sulphur crested cockatoo (Cacatua galerita) feeding, holding food in claws, UK

Konrad Wothe / Sulphur-crested Cockatoo (Cacatua galerita) pair, Iron Range National Park, Cape York peninsula, North Queensland, Queensland, Australia

Konrad Wothe / Sulphur-crested Cockatoo (Cacatua galerita) hanging from branch, Iron Range National Park, Cape York peninsula, North Queensland, Queensland, Australia

Stephen Dalton / Sulphur-crested cockatoo (Cacatua galerita) in flight, controlled conditions

Stephen Dalton / Sulphur-crested cockatoo {Cacatua galerita} flight sequence, multiflash image, controlled conditions, from Australia

Andrew Walmsley / Three Sulphur crested cockatoos (Cacatua galerita) perching on park bench, Sydney Botanic gardens, Australia, August

Andrew Walmsley / Sulphur crested cockatoo (Cacatua galerita) adult peering out of nesting burrow, Sydney Botanic gardens, Australia, August

Andrew Walmsley / Sulphur crested cockatoo (Cacatua galerita) feeding on grass roots, Sydney Botanic gardens, Australia, August

Andrew Walmsley / Sulphur crested cockatoo (Cacatua galerita) playing with stick held by a tourist, Sydney Botanic gardens, Australia, August

Andrew Walmsley / Sulphur crested cockatoo (Cacatua galerita) playing with a Eucalyptus twig, Sydney Botanic gardens, Australia, August/September

Andrew Walmsley / Two Sulphur crested cockatoos (Cacatua galerita) fighting, Sydney Botanic gardens, Australia, August

Andrew Walmsley / Sulphur crested cockatoo (Cacatua galerita) lying on its back playing with a stick, Sydney Botanic gardens, Australia, August

Tim Laman / Sulphur crested cockatoo (Cacatua galerita) calling and displaying with crest and wings extended, Queensland, Australia

Tim Laman / Sulphur crested cockatoo (Cacatua galerita) preening in tree at dawn, Queensland, Australia

Steven David Miller / Sulphur-crested cockatoo {Cacatua galerita galerita} pair mutual grooming, Grampians National Park, Victoria, Australia

Steven David Miller / Sulphur-crested cockatoo {Cacatua galerita galerita} perched, Grampians National Park, Victoria, Australia

Steven David Miller / Sulphur-crested cockatoo {Cacatua galerita galerita} pair mutual grooming, Grampians National Park, Victoria, Australia

Steven David Miller / Sulphur-crested cockatoo {Cacatua galerita galerita} perched with crest raised, Grampians National Park, Victoria, Australia

Jouan & Rius / Sulphur-crested cockatoo (Cacatua galerita) Grampians National Park, Victoria, Australia

Jouan & Rius / Sulphur-crested cockatoo (Cacatua galerita) feeding on wattle flowers, Grampians National Park, Victoria, Australia

Jouan & Rius / Sulphur-crested cockatoo (Cacatua galerita) Grampians National Park, Victoria, Australia

Thomas Marent / Sulphur-crested Cockatoo (Cacatua galerita) portrait, Daintree National Park, Australia

Paul Hobson / Sulpher-crested Cockatoo (Cacatua galerita) adult in flight, calling, South Australia

Steven David Miller / Sulphur-crested Cockatoo (Cacatua galerita), Eungella NP, Eungella, Queensland, Australia

Steven David Miller / Sulphur-crested Cockatoo (Cacatua galerita) Eungella NP, Eungella, Queensland, Australia

Staffan Widstrand / Flock of Sulphur crested cockatoos {Cacatua galerita} grazing on ground, Wilsons Promontory NP, Australia

John Downer / Sulphur crested cockatoo flying {Cacatua galerita} Australia

Roger Powell / Sulphur-Crested Cockatoos (Cacatua galerita) feeding on grass, Victoria, Australia

Roger Powell / Sulphur-Crested Cockatoo (Cacatua galerita)Victoria, Australia

Roger Powell / Sulphur-Crested Cockatoo (Cacatua galerita) portrait, Victoria, Australia

WILLIAM OSBORN / Sulphur crested cockatoo {Cacatua galerita} with crest erect, displaying, Queensland, Australia

Dave Watts / Sulphur-crested Cockatoo {Cacatua galerita} Tasmania, Australia