Martin Willis / Rainbow Lorikeet (Trichoglossus haematodus) pair preening during courtship, Magnetic Island, Queensland, Australia

Tui De Roy / Fiordland Crested Penguin (Eudyptes pachyrhynchus) courting couple allopreening each other, Monroe Beach, West Coast, South Island, New Zealand

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

Martin Willis / Blue and Yellow Macaw (Ara ararauna), and Red and Green Macaw (Ara chloropterus) preening, Jurong Bird Park, Singapore

Martin Willis / Galah (Eolophus roseicapilla) pair preening, Artemis Station, Cape York Peninsula, Australia

WILLIAM OSBORN / Galah cockatoos allopreening {Eolophus roseicapilla} West Queensland, Australia

Pete Oxford / Red and Green Macaw (Ara chloroptera) pair nuzzling and allopreening on branch, Cerrado habitat, Mato Grosso do Sul, Brazil

Tui De Roy / Erect-crested Penguin (Eudyptes sciateri) pair allopreening, Antipodes Island, New Zealand

Mitsuaki Iwago / Budgerigar (Melopsittacus undulatus) couple allopreening during courtship, Sturt National Park, Australia

Tui De Roy / Masked Booby (Sula dactylatra) couple allopreening during courtship, Tower Island, Galapagos Islands, Ecuador

Tui De Roy / Masked Booby (Sula dactylatra) couple allopreening during courtship, Tower Island, Galapagos Islands, Ecuador

Michael Quinton / Great Gray Owl (Strix nebulosa) couple allopreening during courtship, Idaho