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)

Snow covers roofs, streets and the Charles River following a winter blizzard in Boston, Massachusetts January 28, 2015. A powerful blizzard struck Boston and surrounding New England on Tuesday, leaving some 4.5 million people grappling with as much as three feet of snow and coastal flooding. (Photo by Brian Snyder/Reuters)

A Selkirk Rex cat is one of more than 400 breeds of cats being presented at the World Cat Federation two-day show in Dortmund, Germany, on April 21, 2013. (Photo by Frank Augstein/Associated Press)

A bystander walks past a fresco by street artist Seth depicting a girl with a Ukrainian flag walking on tanks in Paris on March 01, 2022. (Photo by Joel Saget/AFP Photo)

Residents display scarecrows with an NHS theme outside their homes in Greenfield for the annual scarecrow parade on April 09, 2020 in Manchester, United Kingdom. There have been around 60,000 reported cases of the COVID-19 coronavirus in the United Kingdom and 7,000 deaths. The country is in its third week of lockdown measures aimed at slowing the spread of the virus. (Photo by Anthony Devlin/Getty Images)

The males, of the Oriental Garden species, are battling over territory in Solapur in the Maharashtra state, India on May 20, 2022. Occasionally, the tussle can be brutal, ending in a fatality with one lizard biting another to encourage them to retreat. (Photo by Ratnakar Hiremath/Solent News)

Street vendors hold campaign posters for presidential candidate Patrice Talon ahead of the second round of Benin's presidential election on Sunday in Cotonou, Benin, March 18, 2016. (Photo by Charles Placide Tossou/Reuters)

Mechanic and welder Sergei Kulagin, 32, strengthens the bracing of a spider sculpture, made by Kulagin, during a demonstration on the wall of an automobile repair workshop in the town of Divnogorsk outside Krasnoyarsk, Siberia, October 15, 2014. Enthusiast Kulagin, who works as a mechanic of an automobile service station, created about 20 sculptures made of used car parts and components during his non-working hours. (Photo by Ilya Naymushin/Reuters)