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)

Portrait category, bronze award winner. Purple-crested Turaco Gallirex porphyreolophus. Lower Mpushini, near Pietermaritzburg, KwaZulu-Natal, South Africa. (Photo by Richard Flack/Bird Photographer of the Year 2022)

An Olive Ridley sea turtle hatchling releases into the sea at Lhoknga beach, Indonesia's Aceh province on January 16, 2024. (Photo by Chaideer Mahyuddin/AFP Photo)

This is the moment a diver appears to shake hands with a giant 52ft whale. The divers were just metres away when one humpback whale – which weighs 36,000kg – extends its giant flipper in a peaceful manner. (Photo by Masa Ushioda/SeaPics/Solent News & Photo Agency)

North Korean girls in similar bathing suits stand under a shower at the Songdowon International Children's Camp, Tuesday, July 29, 2014, in Wonsan, North Korea. The camp, which has been operating for nearly 30 years, was originally intended mainly to deepen relations with friendly countries in the Communist or non-aligned world. But officials say they are willing to accept youth from anywhere – even the United States. (Photo by Wong Maye-E/AP Photo)

Six-month old female liliger cub Eva plays in snow with her mother Zita in the Zoo in Novosibirsk, Russia, Thursday, December 5, 2013. The cub's mother is Zita, a liger – half-lioness, half-tiger, and its father is a lion, Sam. (Photo by Ilnar Salakhiev/AP Photo)

A tourist crosses flooded St. Mark's Square in Venice, Italy on November 11, 2012. Flooding is common this time of year and Sunday's level that reached a peak of 58.66 inches was below the 63 inches recorded four years ago in the worst flooding in decades. (Photo by Luigi Costantini/Associated Press)

The attendants of the Sumptha Raja, Agra Durbar. (Photo by Hulton Archive/Getty Images). 1873