Michael Quinton / Northern Flicker (Colaptes auratus) at nest cavity with begging chicks, Alaska

Roland Seitre / Eastern Wolf (Canis lupus) showing submissive behavior to dominant individual, Omega Park, Montebello, Quebec, Canada

Laurent Geslin / Black backed jackal, submission {Canis mesomelas} Skeleton Coast, Namibia

Laurent Geslin / Two male urban Red foxes, mouths open, one in submissive posture {Vulpes vulpes} London, UK

Cyril Ruoso / Eastern Chimpanzee (Pan troglodytes schweinfurthii) , Frodo the dominant male and hunter, eating a Red River Hog (Potamochoerus porcus) piglet with two females begging, Gombe National Park, Tanzania

Denis-Huot,Denis-Huot / Lion (Panthera leo) mating, Masai-Mara Game Reserve, Kenya. Vulnerable species.

Anup Shah / African Lions (Panthera leo) male and female watching with irritation as a young cub aged 6-9 months approaches, Masai Mara National Reserve, Kenya. December

Heike Odermatt / Black-browed Albatross (Thalassarche melanophrys) chick begging for food, Falkland Islands

Steve Gettle / Barn Swallow (Hirundo Rustica) feeding chicks in nest, Michigan

Steve Gettle / Barn Swallow (Hirundo Rustica) feeding, Michigan

Pete Oxford / Gentoo Penguin (Pygoscelis papua) chick begging for food from parent, Saunders Island, Falkland Islands

Luciano Candisani / Black-browed Albatross (Thalassarche melanophrys) chick begging parent for food, Saunders Island, Falkland Islands