Great Horned Owl sitting on an Aspen tree, Alberta, Canada (© Ambre Haller/Getty Images)

Silver birch (Betula pendula) woodland, Craigellachie National Nature Reserve, Scotland (© Nature Picture Library/Alamy Stock Photo)

Mount Diablo State Park, Kalifornien, USA (© Yuval Helfman/Getty Images)

Mount Diablo State Park, California, USA (© Yuval Helfman/Getty Images)

Camels gather with their herders at the Pushkar Camel Fair, Rajasthan, India (© Anand Purohit/Getty Images)

Jardin des Tuileries leading to the Louvre Museum in Paris, France (© Brian A. Jackson/Getty Images Plus)

Chapel St-Michel d'Aiguilhe, Le Puy-en-Velay, France (© Jaubert French Collection/Alamy Stock Photo)

The Brandenburg Gate seen through a heart-shaped replica of the Berlin Wall, Berlin, Germany (© Britta Pedersen/picture alliance via Getty Images)

Wildflowers in the mist on Mount Howitt in Alpine National Park, Victoria, Australia (© Australian Scenics/Photolibrary/Getty Images Plus)

Sand portrait of WW1 Royal Naval Reservist Richard Davies on Ynyslas Beach, Ceredigion (© Keith Morris Aerial Imagery/Alamy Stock Photo)

Baby hedgehog (© lorenzo104/Getty Images)

The 'Crown of Light' installation is projected onto Durham Cathedral during the 2013 Lumiere Durham festival in England (© Stuart Forster/Alamy)

Trifels Castle in the Palatinate Forest, Rhineland-Palatinate, Germany (© Björn Lauer/Getty Images)

Starlings at sunset in Blackpool (© Mediaworld Images/Alamy)

Fog shrouds the Bavarian Alps in Germany (© Anton Petrus/Getty Images)

For the 30th anniversary of Czechoslovakia's Velvet Revolution, bridges over the Vltava River, including the Charles Bridge and Old Town Bridge Tower, Prague, Czech Republic (© Markus Lange/Offset)

Manatees in the Ichetucknee River in Florida, USA (© Jennifer Adler/Alamy)

Tantallon Castle at sunset from Seacliff Beach, East Lothian (© Scott Masterton/Westend61/Offset)

Gelada monkeys in Simien Mountains National Park, northern Ethiopia (© Marco Gaiotti/plainpicture)

Lantignié in the Beaujolais region of France (© Jon Arnold/Danita Delimont)

The Cutty Sark in Greenwich, London for her 150th anniversary (© Grant Rooney Premium/Alamy)

An agave plant for Fibonacci Day (© Moab Republic/Shutterstock)

A cypress tree in the Atchafalaya Basin, Louisiana, USA (© Chris Moore/Tandem Still + Motion)

Monarch butterflies wintering in Michoacán, Mexico (© Sylvain Cordier/Getty Images)

Highland cattle in Drenthe province in the Netherlands (© defotoberg/Shutterstock)

Jemaa el-Fnaa Square in Marrakesh, Morocco (© Pavliha/Getty Images)

Las Catedrales beach, Galicia, Spain (© Davide Seddio/Getty Images)

The Maroon Bells, near Aspen, Colorado, USA (© Christopher E. Herbert/Getty Images)

Low-lying cloud over Loch Chon, the Trossachs, for St Andrew's Day (© Alistair Dick/Alamy)