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)

New Zealand-based artist Henry Hargreaves became interested in the Last Meal tradition, which inmates waiting on death row have the right to request. He decided to re-create certain serial killers’ last meals in his photography series.

18 year old German photographer Kara (Kara-a) has a passion for macro photography and especially capturing drops of water reflecting various images beyond. Simple beauty of little droplets combined with Kara’s creativity brought up some really entertaining photographs.

Steve McCurry has been a one of the most iconic voices in contemporary photography for more than 30 years, with scores of magazine and book covers, over a dozen books, and countless exhibitions around the world to his name.

Photographer Martin Schoeller examines the visual nuances of twins. Schoeller was born in Munich, Germany in 1968, studied photography at Lette Verein in Berlin and lives in New York. (Photo by Martin Schoeller)

Brendan Fitzpatrick is a commercial photographer specialising in advertising and lifestyle photography. He also creates unique X-ray images marketed under the banner Invisible Light. Brendan is based in Sydney, Australia. (Photo by Brendan Fitzpatrick)

“Scott Linstead is an internationally published, freelance wildlife photographer/writer. His clients include Natural History Magazine, Hewlett Packard, Ranger Rick Magazine and a number of wildlife publications in North America and Europe. Scott's column on the techniques of bird photography appears in every issue of Outdoor Photography Canada”.

Photo: A veiled chameleon extends its tongue to catch a cricket. Canadian wildlife photographer Scott Linstead, formerly an aerospace engineer and high school teacher, uses a device called Phototrap “to not only photograph the elusive, but also the unimaginably quick”. (Photo by Scott Linstead)

“I was doing some event shooting for Bar One's Beer And Wine garden. I was working with these two ladies when all of a sudden I hear an "excuse me” and I see dude step into the frame right when I pressed the shutter button!” (Photo by 17thletter Photography)