Anup Shah / Olive Baboon (Papio anubis) male with three month old young, Gombe National Park, Tanzania

Martin Willis / Budgerigar (Melopsittacus undulatus) father with begging chick at nest cavity, Queensland, Australia

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) egg hatching on father's feet. Atka Bay, Antarctica. August. Winner of the Portfolio category of the Wildlife Photographer of the Year Awards 2019.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri), two males, one brooding young chick, the other incubating hatching egg. Atka Bay, Antarctica. August. Series 4/4.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri), two males, one brooding young chick, the other incubating hatching egg. Atka Bay, Antarctica. August. Series 3/4.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri), two males, one brooding young chick, the other incubating hatching egg. Atka Bay, Antarctica. August. Series 2/4.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri), two males, one brooding young chick, the other incubating hatching egg. Atka Bay, Antarctica. August. Series 1/4.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri), group of three males incubating, one with begging chick. Atka Bay, Antarctica. August.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) male feeding chick aged a few days. Atka Bay, Antarctica. August. Sequence 1/2.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) male feeding chick aged a few days. Atka Bay, Antarctica. August.

Christophe Courteau / Mountain gorilla (Gorilla beringei beringei), silverback and juvenile son. Volcanoes National Park. Rwanda.

Chien Lee / Spike-browed Frog (Sphenophryne cornuta) father transporting froglets, Digul River, West Papua, Indonesia