Lenticular cloud and zebra. (Photo by National Geographic)

National Geographic photographer Steve Winter has spent most of his adult life shooting wild cats. Photo: A 14-month-old cub, cooling off in a pond, is riveted by a deer that appeared near the shore. Tigers are powerful swimmers; they can easily cross rivers four to five miles wide and have been known to swim distances of up to 18 miles. (Photo by Steve Winter/National Geographic)

Andrey Karr from Western Riders Slacklines at sunset above big waves in Nazare, Portugal on December 27, 2017. (Photo by Aidan Williams/National Geographic Travel Photographer of the Year Contest)

“Leopard Hunting a Stork”. “One-shot capture. I watched the leopard stalking the stork, I only had time to focus at 400mm, no time to change to high speed, I watched the stork, and as soon as it flapped its wings, I shot one shot”. (Photo by Paul Rifkin/National Geographic Travel Photographer of the Year Contest)

“The power of nature”. Magma, ash and gas erupt from Mount Etna in December 2015, rising to a height of several kilometres. Winner: Nature. (Photo by Giuseppe Mario Famiani/SIPA Contest)

Tim Laman is a field biologist and wildlife photojournalist. His pioneering research in the rain forest canopy in Borneo led to a PhD from Harvard and his first National Geographic article in 1997. Since then, he has pursued his passion for exploring wild places and documenting little-known and endangered wildlife by becoming a regular contributor to National Geographic. He has eighteen articles to his credit to date, all of which have had a conservation message. Some have focused on endangered species such as Orangutans or Hornbills, while others, such as a series of articles on Conservation International’s Biodiversity Hotspots, have highlighted regions under intense pressure.

Finding just the right spot above the clouds at Camp 1 on Ama Dablam, Danuru Sherpa uses his iPhone to catch up with friends and family. Even at 18,500 feet (5,654 meters), climbers here can check their email and other dispatches from the world below. (Photo by Aaron Huey/National Geographic)

“One artist doesn’t mind if people class her work as rubbish. Thats because all of her pieces are made out of junk found in charity shops, garage sales and in and around her home. Using the likes of buttons, broken jewelry and toy parts, Jane Perkins, from Exeter, UK, has recreated the famous faces of Albert Einstein, Kate Middleton, The Queen, as well as some of the worlds most iconic paintings and photographs”. – Caters News. Photo: Afghan Girl (based on photograph by Steve McCurry/National Geographic). (Photo by Jane Perkins/Caters News)