The fourth annual BigPicture Natural World Photography Competition aims to celebrate the diversity of life on Earth, and encourages people to protect and conserve it. Here: “The Salmon Catchers”. Terrestrial Wildlife. To capture this view of a mother grizzly bear and her cub, photographer Peter Mather set up a camera trap on a log that he knew the bears tended to traverse while fishing for salmon, in the Yukon River watershed in Canada. (Photo by Peter Mather/BigPicture Natural World Photography Competition 2017)

“Family disagreement”. (Photo by Vlado Pirsa/Comedy Wildlife Photo Awards 2019)

Hidden Britain category winner. Garden Spider by Alan Smith from Reading, Berkshire. (Photo by Alan Smith/British Wildlife Photography Awards/PA Wire Press Association)

A zebra walks through the recently flooded Safari Park located at Safari World November 2, 2011 in Bangkok, Thailand. (Photo by Paula Bronstein /Getty Images)

This year’s overall winner and winner of the coast and marine category is George Stoyle with his image “Hitchhikers” of a Lion’s mane jellyfish, photographed at St Kilda, off the Island of Hirta, Scotland. (Photo by George Stoyle/British Wildlife Photography Awards 2016)

A recently rescued grey seal pup looks up from its indoor kennel at the RSPCA West Hatch Wildlife Centre on January 9, 2012 in Taunton, England. The centre is currently dealing with a number of mainly grey seals that have been rescued from the coast due to the recent storms. Staff at the centre hope to release all the seals back into the wild by the spring. (Photo by Matt Cardy/Getty Images)

Goats jumps to cross a stream as they are driven by a herdsman at Dashiwo village, on the outskirts of Beijing January 26, 2015. The Chinese Lunar New Year on February 19 will welcome the Year of the Sheep (also known as the Year of the Goat or Ram). (Photo by Kim Kyung-Hoon/Reuters)