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)

Employees of the Park Royal resort wait for a shuttle to take them to work early in the morning on April 2, 2015 in Acapulco, Mexico. Despite problems with cartel violence Semana Santa is one of the biggest tourist weeks of the year in Acapulco, a city whose entire economy depends on tourism, and officials expect around 350,000 mostly Mexican visitors this week. (Photo by Jonathan Levinson/The Washington Post)

Ulia Matos takes part in a school of theatre, makeup and hair styling graduation contest in Havana, November 16, 2015. (Photo by Reuters/Stringer)

Stranded cars remain in a flooded street during an intense rainstorm in Havana, on April 29, 2015. Two people were killed, three buildings collapsed and another 24 suffered some kind of damage due to the heavy rain that affected several sectors of Havana Wednesday. (Photo by Yamil Lage/AFP Photo)

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)

Vapour bounced off the wings of the Lockheed Martin F-35 Lightning II as it sped over the Welsh mountains at a swift 575mph on February 10, 2022. The jet was taking part in a low-level training exercise through the Mach Loop – a series of valleys in North Wales. (Photo by Thomas Winstone/News Images)

A Secret Service police officer wrestles a protester to the ground after she ran towards a motorcade on its way to the LA Convention Center where North and South American leaders are gathered for the ninth Summit of the Americas in Los Angeles, June 8, 2022. (Photo by Apu Gomes/AFP Photo)