Behaviour winner; Courting Royals: two royal terns in courtship display by Kristian Bell. Another beautiful morning on a beautiful beach on the Gulf Coast of Florida seemed to prompt these two royal terns to commence an intricate courtship dance. The photograph was taken with a Canon 300mm lens and 2x extender. (Photo by Kristian Bell/Deakin University/Royal Society Publishing Photography Competition 2018)

A leaf from a sweetgum tree (Liquidambar styraciflua) lies on the grass at Godewaersvelde early October 27, 2017. (Photo by Philippe Huguen/AFP Photo)

Women take part in Glowork exhibition in Riyadh, Saudi Arabia on September 28, 2017. (Photo by Faisal Al Nasser/Reuters)

In this October 8, 2017, photo, Emily Lynch reacts to hitting her first clay target during a training session for the Trigger Warning Queer & Trans Gun Club in Victor, N.Y. A gay, lesbian and transgender group concerned that extremists have become more emboldened and dangerous have decided to take up arms. The gun club meets once a month to shoot long guns in a field in upstate New York. (Photo by Adrian Kraus/AP Photo)

David Goffin of Belgium meets a koala during a promotional event for the Australian Open tennis tournament at Melbourne Park on January 17, 2018. (Photo by Fiona Hamilton/Reuters/Tennis Australia)

A photographer tested the concentration of several pairs of dogs as he captured their reactions to treat time in a series of shots. Christian Vieler, 47, of Waltrop, Germany, has been a professional dog photographer since 2016. He came up with the idea of snapping two dogs catching treats simultaneously. Here: Basset Hounds. (Photo by Vieler Photography/Caters News Agency)

A Southwest Airlines jet takes off from Reagan National Airport with a thunderhead to the east on June 20, 2017 in Alexandria, VA. (Photo by Jonathan Newton/The Washington Post)

Hitler, Hirohito and Mussolini, in effigy, are about to take a mile-high plunge over Stone Mountain, near Atlanta, Georgia, June 21, 1942, as part of the scrap rubber drive. Private Elias Nour, who arranged the stunt as a farewell party on the eve of his entrance into the army, is on the running board. He guided as the “Axis” plunged to destruction. Spectators had to give a scrap of rubber as the price of admission to the spectacle. (Photo by AP Photo)