Matthew Maran / Red fox (Vulpes vulpes) dog interacting with a vixen in an urban garden. North London, UK. June.

Matthew Maran / Red fox (Vulpes vulpes) dog interacting with a vixen in an urban garden. North London, UK. July.

Marie Read / Black-necked stilts (Himantopus mexicanus) pair performing post-copulatory display (as copulation ends, the male slides off the female leaving his wings draped over her and crossing his bill with hers...

Tony Wu / Four Sperm whales (Physeter macrocephalus) rubbing their heads together while socializing, forming an X shape pattern. Caribbean.

Tony Wu / Four Sperm whales (Physeter macrocephalus) rubbing their heads together while socializing, hanging down. Caribbean.

Jen Guyton / Meerkat pup (Suricata suricatta) huddling close to its family members in the Kalahari Desert, South Africa.

Dave Watts / Colombian spider monkey (Ateles fusciceps rufiventris) group. Captive, Critically endangered species.

Carol Walker / Head portrait of black Andalusian stallion and mare meeting for the first time in southern Spain, Europe.

Marie Read / Northern cardinal (Cardinalis cardinalis) male (right) feeding his mate in spring as part of courtship/pair formation, termed "allofeeding", New York, USA, May.

Marie Read / Northern cardinal (Cardinalis cardinalis) male (right) feeding his mate in spring as part of courtship/pair formation, termed "allofeeding", New York, USA, May.

Marie Read / Northern cardinal (Cardinalis cardinalis) male (right) feeding his mate in spring as part of courtship/pair formation, termed "allofeeding", New York, USA, May.

Aflo / Stray cats, white point cat grooming ginger and white patched tabby, Nagoya, Japan.