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)

Hitler, Hirohito and Mussolini, in effigy, are about to take a mile-high plunge over Stone Mountain, near Atlanta, Georgia, June 21, 1942, as part of the scrap rubber drive. Private Elias Nour, who arranged the stunt as a farewell party on the eve of his entrance into the army, is on the running board. He guided as the “Axis” plunged to destruction. Spectators had to give a scrap of rubber as the price of admission to the spectacle. (Photo by AP Photo)

Two wolfhounds take part in a dogfight in a stadium in the Kyrgyzstan capital Bishkek on November 5, 2017, during fights organized by a local breeders aiming to improve the Asian Shepherd breed, organizers said. (Photo by Vyacheslav Oseledko/AFP Photo)

A hot air balloon in the likeness of Yoda from Star Wars prepares for liftoff at the 21st Philippine International Hot Air Balloon Festival at the former Clark US Air Force base in Pampanga Province, Philippines on February 9, 2017. (Photo by Xinhua News Agency/Rex Features/Shutterstock)

Multiple lightning strikes are seen in this 66 image composite taken over 1.5 hours during a monsoon in Bangkok, Thailand which took place overnight from October 29th to October 30th, 2024. The monsoon season in Bangkok normally lasts from July to October, making this one of the year's last major storms to hit the Thai capital. (Photo by Adryel Talamantes/ZUMA Press Wire/Rex Features/Shutterstock)

Indian Muslim children hold anti-US placards as they participate in a protest meeting against the film “Innocence of Muslims” in Kolkata on October 5, 2012. A low-budget, US-produced “Innocence of Muslims” movie has incited a wave of bloody anti-US violence in Libya, Egypt, Sudan, Tunisia, Yemen and in several other countries across the Muslim world. (Photo by Dibyangshu Sarkar/AFP/AFP Photo)

Anti-bullfighting demonstrators protest against the bulls runs, while standing in cardboard coffins and holding red flowers, on the Ayuntamiento Square in Pamplona northern Spain on Friday July 5, 2013. On July 6, the San Fermin festival will begin with the “txupinazo” , the opening ceremony with people participating in bull runs, music and dance, through the old street of the city. (Photo by Alvaro Barrientos/AP Photo)

A “Free Syrian Army” fighter in the Bustan Pasha neighborhood of Aleppo, Syria, August 21, 2013. (Photo by James Lawler Duggan)