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)

The players of Denmark huddle prior to the FIFA Women's World Cup qualifier match between Denmark and Sweden at Viborg Stadion on September 4, 2018 in Viborg, Denmark. (Photo by Lars Ronbog/FrontZoneSport via Getty Images)

Venezuela: An anti-government protester wearing a Guy Fawkes mask throws a molotov cocktail at the Bolivarian National Police during clashes in Caracas, Venezuela, Thursday, April 17, 2014. Opposition protesters have been demonstrating against high crime, high inflation and shortages of basic goods since mid-February. (Photo by Ramon Espinosa/AP Photo)

(L-R) Taylor Hill, Jasmine Tookes, Elsa Hosk, and Adriana Lima walk the runway during the 2018 Victoria's Secret Fashion Show at Pier 94 on November 8, 2018 in New York City. (Photo by Kevin Mazur/WireImage)

“Microscope images forge an extraordinary bond between science and art, said Hidenao Tsuchiya, Olympus America's Vice President and General Manager for the Scientific Equipment Group. We founded this competition to focus on the fascinating stories coming out of today's life science research laboratories. The thousands of images that people have shared with the competition over the years reflect some of the most exciting work going on in research today – work that can help shed light on the living universe and ultimately save lives. We look at BioScapes and these beautiful images as sources of education and inspiration to us and the world”. – OlympusBioScapes

Photo: Pretarsus of the third leg of a female drone fly (Eristalis tenax), ventral view, by Dr. Jan Michels, Institute of Zoology, Christian-Albrechts-University of Kiel, Germany. (Photo by Olympus BioScapes)

First lady Michelle Obama (R), joined by daughters Sasha Obama (C) and Malia Obama, is presented with the official White House Christmas Tree on November 25, 2011 in Washington, DC. The tree, a 19-foot-tall balsam fir, was grown on Schroeder's Forevergreens farm near Neshkoro, Wisconsin. (Photo by Brendan Hoffman/Getty Images)

U.S. Army Sgt. Patricia Foust receives a free Christmas tree on December 7, 2011 at Fort Carson in Colorado Springs, Colorado. More than 600 soldiers and military families at the base chose trees as part of the annual Trees for Troops program. (Photo by John Moore/Getty Images)