Tony Wu / Bowhead whale (Balaena mysticetus), group socialising in shallow water, aerial view. Part of larger group of more than 50 whales congregating, Sea of Okhotsk sub-population, Russia.

Alex Mustard / Spinner dolphin (Stenella longirostris) pod socialising close to surface. Fury Shoal, Sataya Reef, Marsa Alam, Egypt.

Franco Banfi / Sperm whales (Physeter macrocephalus) socialising with free diver stopped between two individuals, Dominica, Caribbean Sea, Atlantic Ocean, January, Vulnerable species. Model released.

Anup Shah / Southern plains grey langur / Hanuman langur (Semnopithecus dussumieri) females hugging to reinforce rank. Jodhpur, Rajasthan, India. March.

Diane McAllister,Diane McAllister / Japanese Macaque (Macaca fuscata) females gather at one end of the hot springs, Jigokudani, Japan, February

Florian Möllers / Golden snub-nosed monkey (Rhinopithecus roxellana qinlingensis) females, subadults and infants socialising in tree, Zhouzi Nature Reserve, Qinling mountains, Shaanxi, China. April 2006

Alex Mustard / A pair of Australian Sea Lions (Neophoca cinerea) socialising in the shallows. Kangaroo Island, South Australia, Australia. Southern Ocean. November

Chris O'Reilly / European grey wolf (Canis lupus lupus) immature, socialising with handler, Human interaction socialisation project, Wolf conservation, Scandinavia, Captive

Jeff Vanuga / Silhouette of two cowboys playing cards and drinking in a wagon, Wyoming, USA, September 2006, Model released

Luis Quinta / Group of Sperm whales {Physeter macrocephalus} socialising, adults and newborn calf, Azores, Atlantic

Tony Wu / Bowhead whale (Balaena mysticetus), five whales socialising in shallow water, aerial view. Sea of Okhotsk, Russia.

Espen Bergersen / Aerial shot of Humpback whales (Megaptera novaeangliae) socialising, splashing with pectoral fins, Troms, Norway, January.