A woman walks inside a building in downtown Havana, Cuba April 21, 2016. (Photo by Alexandre Meneghini/Reuters)

Shortlisted: Pooyan Shadpoor, Houcheraghi. While walking along the shore of Larak, Iran – an island in the Persian Gulf – Shadpoor came across this luminous scene. The “magical lights of (the) plankton ... enchanted me so that I snapped the shot”, he writes. (Photo by Pooyan Shadpoor/2016 EPOTY)

Astronaut Donald R. Pettit would often rig an array of as many as six cameras in the cupola windows and set them all to fire continuously for events such as sunsets, which only last around seven seconds on the ISS. (Photo by Donald R. Pettit)

Masked Guggen music bands parade through the streets on the occasion of the beginning of the Fasnacht Carnival of Lucerne, Switzerland, early 23 February 2017. (Photo by Urs Flueeler/EPA)

A boy jumps into a pool of mud during the traditional “Bloco da Lama” or “Mud Street” carnival party, in Paraty, Brazil, Saturday, February 25, 2017. Legend has it the “bloco” was born in 1986 after local teens hiking in a nearby mangrove forest smeared themselves with mud to discourage mosquitoes and then wandered through Paraty. The party grew year after year, but revelers eventually were banned from parading in the colonial downtown after shopkeepers complained pristine white walls were stained with the hard-to-remove mud. (Photo by Mauro Pimentel/AP Photo)

A mouse rides on the back of a frog in floodwaters in the northern Indian city Lucknow June 30, 2006. (Photo by Pawan Kumar/Reuters)

Capgrossos de Mataro team members fall during the 25th Castells' contest at the Tarraco Arena in Tarragona, Catalonia, northeastern Spain, 02 October 2016. The “Castells” is a popular event in which people create human towers up to a height of between six and ten levels. (Photo by Jaume Sellart/EPA)

The Wildscreen festival is the world’s biggest celebration of screen-based natural history storytelling which takes place every two years in Bristol. Here: “Walrus in Midnight Sun”. Walrus feed mostly on bivalves in productive, shallow and often sandy habitats in the Arctic. This individual, though, arrived on a beach outside Tromsø, northern Norway, and found comfort on a stranded dead sperm whale. After two weeks he approached Audun, and only half a metre away he stretched his tusk forward and touched his hand gently. “This was one of the most memorable moments of my life”, Rikardsen says. He named the 500kg male Buddy. After two months, the dead whale was decomposed and Buddy suddenly disappeared. (Photo by Audun Rikardsen/Wildscreen 2016)