Tony Wu / Humpback whale (Megaptera novaeangliae australis) female with suckling calf. Vava'u Islands, Tonga.

Mark Raycroft / Woodland Caribou (Rangifer tarandus caribou) mother nursing calf, Newfoundland, Canada

Suzi Eszterhas / Leopard (Panthera pardus) six-week-old cub nursing, Jao Reserve, Botswana

Eric Baccega / Female Uganda kob (Kobus kob thomasi) suckling calf. Murchisson Falls National Park, Uganda. February.

Sam Hobson / Red fox vixen (Vulpes vulpes) with young cubs. Bristol, UK. April

Suzi Eszterhas / Proboscis Monkey (Nasalis larvatus) mother nursing four month old baby, Sabah, Borneo, Malaysia

Andy Rouse / Bengal tiger (Panthera tigris tigris) female 'T19 Krishna' carrying 2 month cub, Ranthambhore National Park, India.

Suzi Eszterhas / Capybara (Hydrochoerus hydrochaeris) mother nursing young, Pantanal, Brazil

Fiona Rogers / Celebes / Black crested macaque (Macaca nigra) female with suckling infant aged 9-12 months, Tangkoko National Park, Sulawesi, Indonesia.

Fiona Rogers / Western chimpazee (Pan troglodytes verus) female 'Fanle' aged 13 years with suckling infant male 'Flanle' aged 3 years, Bossou Forest, Mont Nimba, Guinea. January 2011.

Floris van Breugel / Two Bull Northern Elephant Seals (Mirounga angustirostris) face off before fighting in the middle of the extensive Piedras Blancas rookery with over 150 seals just in this photo, mostly pregnant or nu...

Florian Möllers / Quinling Golden snub nosed Monkey (Rhinopitecus roxellana qinlingensis), infant suckling Zhouzhi Nature Reserve, Qinling Mountains, Shaanxi, China.