Jonathan Harrod / Variable Oystercatcher (Haematopus unicolor) pair displaying and chasing away rival pair, Coromandel Peninsula, New Zealand

Colin Monteath / Antarctic Fur Seal (Arctocephalus gazella) male defending territory, South Georgia Island, Antarctica

Mark Raycroft / White-tailed Deer (Odocoileus virginianus) buck branch licking to mark territory, North America

Mark Raycroft / White-tailed Deer (Odocoileus virginianus) buck rubbing antlers against tree trunk to mark territory, North America

Mark Raycroft / White-tailed Deer (Odocoileus virginianus) buck branch licking to mark territory, North America

Mark Raycroft / White-tailed Deer (Odocoileus virginianus) buck rubbing tree trunk to mark territory, North America

Mark Raycroft / White-tailed Deer (Odocoileus virginianus) buck licking plant to mark territory, North America

Tui De Roy / Adelie Penguin (Pygoscelis adeliae) males displaying to claim nest sites, Prydz Bay, eastern Antarctica

Theo Allofs / Hippopotamus (Hippopotamus amphibius) territorial display, Moremi Game Reserve, Okavango Delta, Botswana. Sequence 1 of 3

Theo Allofs / Hippopotamus (Hippopotamus amphibius) territorial display, Moremi Game Reserve, Okavango Delta, Botswana. Sequence 3 of 3

Theo Allofs / Hippopotamus (Hippopotamus amphibius) territorial display, Moremi Game Reserve, Okavango Delta, Botswana. Sequence 2 of 3

Pete Oxford / Meerkat (Suricata suricatta) scent marking, Makgadikgadi Pans, Kalahari Desert, Botswana