Iranians flash the victory sign from their car while celebrating on a street in northern Tehran, Iran, Thursday, April 2, 2015, after Iran's nuclear agreement with world powers in Lausanne, Switzerland. The United States, Iran and five other world powers on Thursday announced an understanding outlining limits on Iran's nuclear program so it cannot lead to atomic weapons, directing negotiators toward achieving a comprehensive agreement within three months. (Photo by Ebrahim Noroozi/AP Photo)

People walk on the street in Samara, Russia on July 18, 2017. (Photo by David Mdzinarishvili/Reuters)

A workman walks past a large mural on the side of a building during the “Sand Sea & Spray” Urban Art Festival in Blackpool, north west England on July 11, 2015. (Photo by Oli Scarff/AFP Photo)

A view of a large poster depicting Russian opposition leader Alexei Navalny behind bars with a dove freeing him from detention, by an unidentified street artist known as Harry Greb, in downtown Rome, Italy, 25 January 2021. Navalny was detained after his arrival to Moscow from Germany on 17 January 2021. A Moscow judge on 18 January ruled that he will remain in custody for 30 days following his airport arrest. Navalny urged Russians to take to the streets to protest against President Putin's rule. (Photo by Fabio Frustaci/EPA/EFE)

A ballet dancer brushes on blush as she prepares for a street ballet performance in Mexico City, Saturday, July 28, 2018. In this sprawling megalopolis notorious for its clogged streets, a theater company sent out tutu-clad dancers out to delight motorists at snarled intersections with snippets from ballet classics like “The Nutcracker” and “Swan Lake” all in the 58 seconds it takes for the light to go from red to green. (Photo by Emilio Espejel/AP Photo)

American model Bella Hadid comes out of her hotel on September 25, 2018 in Paris, France. (Photo by Pierre Suu/Getty Images)

The battle by Jose Garcia, US. Category: bird behaviour. A great white heron (Ardea herodias occidentalis) fighting a green snake in the Florida Everglades. The fight lasted for nearly 20 minutes with the heron having to release its prey. (Photo by Jose Garcia/2017 Bird Photographer of the Year Awards)

Bloodthirsty by Thomas P. Peschak, Germany/South Africa — winner, Behaviour: birds. When rations run short on Wolf Island, in the remote northern Galápagos, the sharp-beaked ground finches become vampires. Their sitting targets are Nazca boobies and other large birds. The finches rely on a scant diet of seeds and insects, which regularly dries up, so they drink blood to survive. ‘I’ve seen more than half a dozen finches drinking from a single Nazca booby,’ says Tom. Rather than leave their nests the boobies tolerate the vampires, and the blood loss doesn’t seem to cause permanent harm. (Photo by Thomas P. Peschak/2018 Wildlife Photographer of the Year)