Steven Kazlowski / Polar bear (Ursus maritimus) young bear rolling around in the snow, on newly formed pack ice during autumn freeze up, Beaufort Sea, off Arctic coast, Alaska

Matthew Maran / Great created grebe (Podiceps cristatus) with chick following, and person swimming in pond, Hampstead Heath, London, July 2014.

Jerry Monkman / Woman mountain biking on a trail in an abandoned granite quarry on Millstone Hill, Barre, Vermont, USA. autumn. Model released, October 2010

Ernie Janes / Household Cavalry exercising their horses on Holkham Beach, Norfolk, UK, July 2008

Mitsuaki Iwago / Black-footed Albatross (Phoebastria nigripes) juvenile exercising its wings, Hawaii

Mark Raycroft / Jack Russell or Parson Terrier (Canis familiaris) adult jumping through agility tire

Pete Oxford / Crested eagle chick on nest exercising wings {Morphnus guianensis} Amazon rainforest. Peru, South America.

SCOTLAND: The Big Picture / Family mountain biking through forest, Cairngorms National Park, Scotland, UK, November 2011.

SCOTLAND: The Big Picture / Walker silhouetted at sunset on Braeriach, Cairngorms National Park, Scotland, UK.November

SCOTLAND: The Big Picture / Walker silhouetted at sunset on Braeriach, Cairngorms National Park, Scotland, UK.November

Charlie Summers / Broad-tailed hummingbird (Selasphorus platycercus) chick fledging, exercising wings,. Aurora, Colorado, USA. August.

David Allemand / Little owl (Athene noctua) chicks playing, one juming and exercising wings, Saragossa, Spain, July.