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)

Touching and dramatic portraits and landscape shots have won prizes at Australia's prestigious photography prize. Photo: Winner of the NSW (New South Wales) prize: Peter Solness said: “I wanted to re-imagine the lost waterways, so I got my light-painting tools to work. In this image, water is being released from the top of the historic Centennial Park No. 2 Reservoir, which was built in 1925 and holds 90 megalitres of water. After 89 years of incarceration these waters now run free!”. (Photo by Peter Solness/Head On)

Cao Ri and Xu Jiaqian have a wedding photograph taken in a pool at the Qianyishi Underwater Photography Studio in Beijing, China on September 7, 2017. (Photo by Thomas Peter/Reuters)

(L-R) Playmate Victoria Silvstedt, Donald Trump and Melania Knauss at the Playboy 50th Anniversary celebration December 4, 2003 in New York City. (Photo by Peter Kramer/Getty Images)

Women hold hands during the Tokyo Rainbow Pride parade celebrating lesbian, gay, bisexual, and transgender (LGBT) culture in Tokyo, Japan, May 8, 2016. (Photo by Thomas Peter/Reuters)

North Korean soldiers keep watch at the bank of the Yalu River, near the North Korean town of Sinuiju, opposite Dandong in China's Liaoning province, September 10, 2016. (Photo by Thomas Peter/Reuters)

Hunter Chiaki Kodama guts a deer in a shed in Oi, Fukui Prefecture, Japan, November 17, 2016. A small but growing number of Japanese women enter the male-dominated world of hunting, where it was once taboo for men to even speak to a woman before going on a hunt. (Photo by Thomas Peter/Reuters)

A participant of the sled dogs race in action with the dogs in Stroehen (Lower Saxony), Germany, 18 October 2015. It is the first round of the North German Championship. (Photo by Peter Steffen/EPA)