Jami Tarris / Walrus (Odobenus rosmarus) bull, Spitsbergen, Svalbard, Norway
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Mark Raycroft / Moose (Alces alces) bull browsing, North America
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SCOTLAND: The Big Picture / Orca whales (Orcinus orca) pod surfacing together, Shetland, Scotland, UK. April.
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SCOTLAND: The Big Picture / Orca (Orcinus orca) surfacing and blowing, Shetland, Scotland, UK, August.
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TJ Rich / Wirehaired daschund, Staffordshire bull terrier and Hungarian viszla in autumn colours, Wiltshire, UK
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Alex Hyde / Southern Elephant Seal bull (Mirounga leonina) close up portrait, King Haakon Bay, South Georgia. November.
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Donald M. Jones / Elk (Cervus elaphus) bull bugling, Alberta, Canada
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Ann & Steve Toon / Leopard / mountain tortoise (Stigmochelys pardalis) with elephant bull (Loxodonta africana) behind in water, Addo elephant national park, Eastern Cape, South Africa, September
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Chase Dekker / Moose (Alces alces shirasi) bull flehming in autumn, Grand Teton National Park, Wyoming
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Chase Dekker / Moose (Alces alces shirasi) bull flehming in autumn, Grand Teton National Park, Wyoming
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Chase Dekker / Moose (Alces alces) bull in tundra, Mount Rundle, Banff National Park, Alberta, Canada
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Will Burrard-Lucas / Black and white image of African elephant (Loxodonta africana) bulls males facing off against each other, Tsavo Conservation Area, Kenya. Editorial use only.