In this undated photo made available by journal Nature on January 15, 2014, a northern bald ibis (Geronticus eremita) flies in Tuscany, Italy. A new study released Wednesday, January 15, 2014 says the birds choreograph the flapping of their wings, getting a boost from an updraft of air in the wake of the flapping wings by flying behind the first bird and off to the side. When a flock of birds take advantage of these aerodynamics, they form a V. (Photo by Markus Unsöld/AP Photo)

Polar bear twins make their first public appearance with their mother “Freedom” at Ouwehands Zoo Rhenen, in Rhenen, The Netherlands, 19 February 2015. The twins, who were born in November 2014, have not been named because their gender has not yet been determined. (Photo by Bart Maat/EPA)

A female Indian rhinoceros called Maruska eats a vegetable birthday cake on her first birthday celebration at the Plzen Zoo on February 3, 2015 in Plzen, Czech Republic. (Photo by Ladislav Nemec/Isifa)

Participants wearing fantasy costumes attend the 4th Hero Festival in Marseille, France on November 11, 2017. The 4th Hero Festival edition has attracted all sorts of people to role play their favourite characters from all kinds of movies and comic book legends. (Photo by Jean-Paul Pelissier/Reuters)

Jean-Pierre Giagnoli walks through a crowded area of vendors hawking cat related goods at CatCon LA in Los Angeles, on Sunday, June 26, 2016. (Photo by Richard Vogel/AP Photo)

Armed forces veteran Frank Simpson at the Portico library being camouflaged by body artist Carolyn Roper in Manchester, UK on May 16, 2016 as part of the #CountThemIn campaign launched on Monday by the Royal British Legion. (Photo by Jon Super/Royal British Legion/PA Wire)

Takeoka Chisaka, Hiroshima, Japan. “One morning in August 1945, I was walking home from the night shift at a factory in Hiroshima. As I reached my door, there was a huge explosion. When I came to, my head was bleeding and I had been blasted 30m away. The atomic bomb had detonated. When I found my mother, her eyes were badly burned. A doctor said they had to come out, but he didn’t have the proper tools so used a knife instead. It was hellish. I became a peace-worker after the war. In the 1960s, at a meeting at the UN, I met one of the people who created the atomic bomb. He apologised”. (Photo and caption by Sasha Maslov)

British model Jourdan Dunn arrives for the premiere of “The Killing of a Sacred Deer” during the 70th annual Cannes Film Festival, in Cannes, France, 22 May 2017. The movie is presented in the Official Competition of the festival which runs from 17 to 28 May. Dress by Elie Saab Haute Couture. (Photo by Julien Warnand/EPA)