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)

Volunteer of the SICS “Italian rescue dog school”, during a water rescue training session, inside the Averno lake in Pozzuoli. Italy, on October 26, 2024. (Photo by Vincenzo Izzo/Sipa USA)

A visitor poses for a picture during Sao Paulo Fashion Week in Sao Paulo, Brazil, March 16, 2017. (Photo by Nacho Doce/Reuters)

Sakakibara Kikai's engineer Go Sakakibara poses with the bipedal robot Mononofu during its demonstration at its factory in Shinto Village, Gunma Prefecture, Japan on April 12, 2018. Developed at Sakakibara Kikai, a maker of farming machinery, LW-Mononofu is a 28-feet tall, two-legged robot weighing in at more than 7 tonnes. It contains a cockpit with monitors and levers for the pilot to control the robot's arms and legs. (Photo by Kim Kyung-Hoon/Reuters)

A pine marten – one of a few wild mammals doing well in Britain (although they number just 3,700). A fifth of the country’s wild mammals are at high risk of extinction, research shows. (Photo by Maurice Flynn/The Mammal Society)

Women are reflected in a puddle as they walk across Red Square in Moscow, Russia on April 26, 2018. (Photo by Yuri Kadobnov/AFP Photo)

UK Love Island beauty Samira Mighty (L) seen arriving at Mahiki Kensington on November 16, 2018 in London, England. (Photo by CURLEY)

A street entertainer waits for tourists in Havana, Cuba on October 2009. (Photo by Desmond Boylan/Reuters)