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

Suzi Eszterhas / Leopard (Panthera pardus) six-week-old cub nuzzling mother, Jao Reserve, Botswana

Winfried Wisniewski / African Lion (Panthera leo) males nuzzling, Masai Mara, Kenya

Sandesh Kadur / Wide angle shot of a pair of Blue footed boobies (Sula nebouxii) displaying, Galapagos Islands, Ecuador.

Sandesh Kadur / Pair of Waved albatrosses (Phoebastria irrorata) displaying, tapping beaks, Galapagos Islands, Ecuador.

Cyril Ruoso / Minden / Long-tailed Macaque (Macaca fascicularis) pair grooming, Khao Sam Roi Yot National Park, Thailand

Richard Du Toit / Burchell's Zebra (Equus burchellii) trio nuzzling, Itala Game Reserve, South Africa

Frederique Olivier / Close-up of a pair of Black browed albatrosses (Thalassarche melanophris) mutual grooming, New Island, Falkland Islands.

Frederique Olivier / Pair of Black browed albatrosses (Thalassarche melanophris) display bonding, touching beaks, New Island, Falkland Islands.

Frederique Olivier / Pair of King penguins (Aptenodytes patagonicus) regurgitating and calling with chick nearby, Macquarie Island, Sub-Antarctic Australia.

Francois Savigny / Lionesses grooming and cub {Panthera leo} Moremi NP Botswana

Markus Varesvuo / Japanese / Red-crowned crane (Grus japonicus) two calling and dancing, part of bonding and courtship display, Hokkaido Japan February