In this photo taken Friday, September 4, 2015, tourists Sarah and John Scott from Worcester, England, take a step back as a male silverback mountain gorilla from the family of mountain gorillas named Amahoro, which means “peace” in the Rwandan language, unexpectedly steps out from the bush to cross their path in the dense forest on the slopes of Mount Bisoke volcano in Volcanoes National Park, northern Rwanda. Deep in Rwanda's steep-sloped forest, increasing numbers of tourists are heading to see the mountain gorillas, a subspecies whose total population is an estimated 900 and who also live in neighboring Uganda and Congo, fueling an industry seen as key to the welfare of the critically endangered species as well as Rwanda's economy. (Photo by Ben Curtis/AP Photo)

An employe of Russian Space Training Center hangs out to dry space suits of Russian cosmonaut Anatoly Ivanishin, NASA's U.S. flight engineer Kathleen Rubins, and Japanese space agency's flight engineer Takuya Onishi, right, after their undergoing training near in Noginsk, 60 km (38 miles) east of Moscow, Russia, Wednesday, July 2, 2014. The training was intended to simulate the capsule landing on water. Russian cosmonaut Anatoly Ivanishin, Japanese space agency's flight engineer Takuya Onishi, and NASA's U.S. flight engineer Kathleen Rubins are being trained for a future mission to the International Space Station. (Photo by Alexander Zemlianichenko/AP Photo)

“Eye of a toad”. Animal Portraits, Łukasz Bożycki, Poland. Early spring sees a pond near Łukasz’s home city of Warsaw, Poland, full of mating frogs and a few toads. On this March day, Łukasz shared the pond with them for an evening, sitting in the icy water in his chest-high waders, keeping as still as possible, despite the numbing cold, so that the amphibians could get used to him. “I wanted to find a fresh way of portraying the amphibians”, he says, “at water level”. Using a telephoto lens, he focused on one lone toad and waited for the sun to dip almost below the horizon before pressing the shutter, using flash to bring out the details in the shadow. His prize was “the glorious pool of sunset colour” and fiery glow of the toad’s eye. Nikon D80 + 70-300mm f4.5-5.6 lens + extension tube; 1/125 sec at f9 (-2.3 e/v); ISO 100; built-in flash. (Photo by Łukasz Bożycki)

Swedish brown bears “Fred” and “Frode” play in the snow on January 30, 2014 at the Natur- und Umweltpark (NUP) animal park in Guestrow, northeastern Germany. Despite of icy temperatures, the bear brothers took a break from their winter rest. (Photo by Bernd Wuestneck/AFP Photo/DPA)

People enjoy skating at the open air Christmas ice rink on the first floor of the Eiffel Tower after its reopening on December 19, 2016 in Paris The ice rink of about 200 square metres and on the first floor of the tower (57 metres above the ground) is open to the public until February 19, 2017. (Photo by Joel Saget/AFP Photo)

A woman falls to the beach after she was attacked by three white women segregationists, when she attempted a wade-in with several African American and white desegregationist demonstrators, June 23, 1964, St. Augustine Beach, Fla. The people in the photo are unidentified. (Photo by AP Photo/JK)

Local people check the growth of mussels at a river in Haian County on November 2, 2017 in Nantong, Jiangsu Province of China. Fish, shrimp, crab and mussel farming cleans the river and increases the villagers' income at Haian county in Jiangsu. (Photo by VCG/VCG via Getty Images)

Lava cascades down the slopes of Mayon volcano as seen from Legazpi city, Albay province, around 340 kilometers (210 miles) southeast of Manila, Philippines, Monday, January 15, 2018. More than 9,000 people have evacuated the area around the Philippines' most active volcano as lava flowed down its crater Monday in a gentle eruption that scientists warned could turn explosive. (Photo by Earl Recamunda/AP Photo)