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)

Sandrine Kerfante has had a fascination with “doubles” ever since meeting her mother’s twin as a child. In 2012, this lifelong captivation inspired her to create a blog called twin-niwt, which celebrates photographs of doubles in all their forms. “I’m fascinated by the idea of the duo, repetition, symmetry, reflection, mirror games and all the symbolism associated with it”, she says. “I think it’s a topic often present in photography, more or less consciously”. (Photo by Sandrine Kerfante/The Guardian)

The ferocity of crises worldwide is forcing a record number of people to flee their homes, seeking some form of safety within their own country or across international borders. There are 65.3 million displaced people worldwide, including 21.3 million refugees. Most have lost their homes to armed conflict or natural disasters but other factors, such as extreme poverty and climate change, also drive displacement. The International Organisation for Migration commissioned photojournalist Muse Mohammed to document the plight of the displaced. (Photo by Muse Mohammed/IOM)

These breath-taking photographs reveal the everyday lives of animals living in the wild. The incredible images were taken by wildlife photographer Wim van dan Heever, from Pretoria, South Africa, during trips to locations including Japan, Botswana and Svalbard. The 43-year-old has been photographing wildlife since he was a young boy and turned his passion for animals into a career and set up ODP Safaris. He has travelled across the globe to photograph wild animals – from lions and tigers, to elephants, dolphins and eagles – as they hunt, give birth and graze in their natural habitats. Here: Lions submerged in water. (Photo by Wim van den Heever/Caters News)

Daniel Fox inside the Mendenhall Glacier, in September 2014, in Juneau, Alaska. Driving in an open-roofed jeep is no longer the fashionable way to see wildlife – as this adventurer shows. A keen wildlife photographer has circled islands in the south of Alaska, the United States, in a kayak to see spectacular scenery and animals. Daniel Fox, 40, from San Francisco spent three months travelling around the islands by kayak, meeting sea lions and brown bears along the way. (Photo by Daniel Fox/Barcroft Media)

Italian actress Sophia Loren attends the Cannes Film Festival in Cannes, France, 1954. (Photo by AGIP/RDA/Getty Images)

With its huge eyes, comical name and diminutive size, Mark R. Smith’s image of a baby Hawaiian bobtail squid can’t help but raise a smile. A curiously endearing creature, the cephalopod is just 1.5cm across, its mantle cavity bearing more than a passing resemblance to a rather natty shower cap. But it is also a beautiful example of symbiosis – nature’s version of “I’ll scratch your back if you scratch mine” – for on the underside of the squid is a light organ which houses bioluminescent bacteria. The squid offers the bacteria protection and food, while the bacteria emit a glow – a handy trait that the squid uses to offset its silhouette, helping it to evade predators in the depths below. Mark R. Smith’s entry combines several images of a Hawaiian bobtail squid with different focus lengths to create a final picture with greater depth of field than normal. (Photo by Mark R. Smith/Wellcome Images/Macroscopic Solutions)

A selection of work by four photojournalists who have won grants of $10,000 and editorial support from the agency. Here: “Chasing Winter” by Katie Orlinksy. In late summer and early autumn polar bears flock to the native village of Kaktovik in the Alaskan Arctic to eat at “the boneyard” – the remains of whales annually hunted by the community. (Photo by Katie Orlinsky/Getty Images)