A Syrian refugee girl covers herself with a blanket as she stands outside tents at a makeshift settlement in Bar Elias in the Bekaa valley January 5, 2015. Lebanon enforced new immigration controls at the Syrian border on Monday in a move to gain control of the steady stream of refugees from its much larger neighbour. (Photo by Mohamed Azakir/Reuters)

Pakistani children cool themselves off in a stream in Peshawar, Pakistan, Monday, June 29, 2015, during Muslim's fasting month of Ramadan. (Photo by Mohammad Sajjad/AP Photo)

Elvis Presley tribute artist Bruce Stewart (L) of Georgian Bay, Ontario passes Lorenz Francke of Scarborough, Ontario during the four-day Collingwood Elvis Festival in Collingwood, Ontario July 25, 2015. Featuring over 120 Elvis tribute artists, it is the world's largest Elvis festival and last year hosted 30,000 visitors. (Photo by Chris Helgren/Reuters)

People visit an art installation “Alley of Flying Umbrellas” in central St. Petersburg, Russia, May 15, 2015. Art installation inspired by “Umbrella Sky Project” of Portuguese town of Agueda and was made of 500 colored umbrellas. (Photo by Anatoly Maltsev/EPA)

In this handout provided by the National Aeronautics and Space Administration (NASA), SpaceX's Falcon 9 is moved to the launch pad prior to the rocket's Thales Alenia Space launch attempt on April 26, 2015 in Cape Canaveral, Florida. (Photo by NASA via Getty Images)

Hindu women perform a ritual known as Aarti around a Shivling (a symbol of Lord Shiva) on the last day of Jaya Parvati Vrat festival in Ahmedabad, India, July 10, 2017. (Photo by Amit Dave/Reuters)

Animal rights activists protest against the use of animal leather in fashion businness, a few days before the fashion week opening in Milan, Italy, 16 September 2018. (Photo by Matteo Bazzi/EPA/EFE)

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)