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)

Pickles the cat was once abandoned and had a hard time finding a home because of his size until he met a couple who have a heart and home big enough to take him in.

In this handout image supplied by Qatar 2022 The Al-Rayyan stadium is pictured in this artists impression as Qatar 2022 World Cup bid unveils it's stadiums on September 16, 2010 in Doha, Qatar. It has been designed to include a “media facade” that includes a membrane that acts as a screen for projections; news, commercials, sports updates and current tournament information and matches. (Photo by Qatar 2022 via Getty Images)

India's Central Reserve Police Force personnel take part in a rehearsal for the Republic Day parade on a cold winter morning in New Delhi January 8, 2014. (Photo by Ahmad Masood/Reuters)

Hooded demonstrators vandalise a shop window in Mexico City, during the commemoration of the 50th anniversary of the 1968 Tlatelolco student massacre, on October 2, 2018. Fifty years ago, Mexican troops opened fire on student demonstrators, killing hundreds just days before Mexico City hosted the 1968 Olympics – one of the darkest episodes in a year of global turbulence. (Photo by Ronaldo Schemidt/AFP Photo)

Underwater photographer of the year – winner. Dancing Octopus by Gabriel Barathieu (France). Location: Island of Mayotte, off the coast of south-east Africa. “Balletic and malevolent”, one judge said of this octopus, hunting in a lagoon. Barathieu waited until spring tides when there was just 30cm of water on the flats and plenty of light in the shallows. (Photo by Gabriel Barathieu/UPY2017)

An installation consisting of a series of bird boxes is displayed in a tree in Duncan Terrace Gardens in Islington on March 24, 2011 in London, England. The boxes by artists Bruce Gilchrist and Jo Joelson of “London Fieldworks”, were designed to reflect the architecture of the Georgian terraces and flats that surround the park in the community gardens. (Photo by Dan Kitwood/Getty Images)

A 42-day-old white bengal tiger cub (bottom), the first of its kind born in Peru, sleeps between toys as he is presented at the Huachipa's zoo in Lima on August 6, 2013. (Photo by Ernesto Benavides/AFP Photo)