Tui De Roy / Great frigatebird (Fregata minor) female incubating egg as male grooms her. Espanola Island, Galapagos, Ecuador, May.

Ben Osborne / A young male African lion (Panthera leo) grooms a lioness, Savuti, Botswana. Taken on location for BBC Planet Earth series 2005

Ben Osborne / A young African lioness (Panthera leo) grooms a young male lion, Savuti, Botswana. Taken on location for BBC Planet Earth series 2005

Ben Osborne / A young African lioness (Panthera leo) grooms a young male lion, Savuti, Botswana. Taken on location for BBC Planet Earth series 2005

Ben Osborne / A young male African lion (Panthera leo) grooms a lioness, Savuti, Botswana. Taken on location for BBC Planet Earth series 2005

Steven Kazlowski / Sea otter (Enhydra lutris) grooms itself in icy waters off Columbia Glacier in Prince William Sound, Chugach National Forest, Alaska, USA, May

Steven Kazlowski / Sea otter (Enhydra lutris) grooms itself in icy waters off Columbia Glacier in Prince William Sound, Chugach National Forest, Alaska, USA, May

Kristel Richard / A soldier, from the King's Troop, Royal Horse Artillery, grooms an Irish Draft horse at the St John's Woods Barracks, London, England, UK. 2009

Anup Shah / Gelada baboon (Theropithecus gelada) juvenile grooms adult female, Simien Mountains National Park, Ethiopia, November

Anup Shah / Gelada baboon (Theropithecus gelada) male yawning while female sits and grooms, Simien Mountains National Park, Ethiopia, November

Andrew Parkinson / Adult Brown / European hare {Lepus europaeus} grooms one of its hind legs, Derbyshire, UK

Andrew Parkinson / Adult Brown / European hare {Lepus europaeus} grooms itself whilst sitting in a field margin, Derbyshire, UK

Bengt Lundberg / Man grooms fighting cock, E-sarn, Thailand

Doug Perrine / Orange skunk clownfish / anemonefish grooms eggs in Magnificent anemone, Thailand

Barrie Britton / Japanese macaque (Macaca fuscata) female grooms juvenile. Kojima Island, Japan

Anup Shah / Chimpanzee 'Fifi' grooms newborn baby (3-days-old) Gombe NP, Tanzania 2003

Anup Shah / Chimpanzees grooming, 'Fifi' + 'Furaha', Gombe NP, Tanzania 2003

Anup Shah / Chimpanzee mother grooms baby, 'Fifi' + 'Furaha', Gombe NP, Tanzania 2003

Justine Evans / White handed gibbon alpha male grooms female {Hylobates lar} Khao Yai NP, Thailand

Anup Shah / 'Fanni' grooms son 'Fudge' while other son 'Fundi' plays {Pan troglodytes schweinfurtheii}, Kasekela community, Gombe NP, Tanzania. 2002