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)

A Nihang' or Sikh warrior performs “Gatka”, an ancient form of Sikh martial arts, during a Fateh Divas celebration a day after the Hindu festival Diwali, in Amritsar on November 5, 2021. (Photo by Narinder Nanu/AFP Photo)

A married Hindu woman performs rituals around a banyan tree at Vat Savitri festival in Ahmedabad, India, Tuesday, June 14, 2022. Vat Savitri is celebrated on a full moon day where women pray for the longevity of their husbands. (Photo by Ajit Solanki/AP Photo)

A Rajasthani man displays his moustache during the closing ceremony of annual Camel Fair in Pushkar, in India's desert state of Rajasthan, on November 8, 2022. (Photo by Himanshu Sharma/AFP Photo)

A mahout guards the elephants during the annual Vrischikolsavam festival, which features a colourful procession of decorated elephants along with drum concerts, at a temple in Kochi, India, November 18, 2017. (Photo by Sivaram V/Reuters)

People walk in the rain in Hyderabad, India, Saturday, November 20, 2021. More than a dozen people have died and dozens are reported missing in the southern Indian state of Andhra Pradesh after days of heavy rains, authorities said. (Photo by Mahesh Kumar A./AP Photo)

This photo taken on November 4, 2019 shows people taking part in a fish catching competition in a paddy field in Leishan county in China's southwestern Guizhou province, to celebrate the new year festival Miao people. (Photo by AFP Photo/China Stringer Network)

A fisherwoman prepares a meal in her home in a fishing village in Virar, about 40 km (25 miles) from Mumbai December 27, 2005. (Photo by Adeel Halim/Reuters)