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)

Soldiers on exercise in Kenya. The image, by Sergeant Dek Traylor, is among the section winners in the UK Army Photographic Competition 2018. (Photo by Sergeant Dek Traylor/PA Wire Press Association)

A pedestrian carries an umbrella as they stroll past an advertisment as a rainstorm moves through Sacramento, Calif., Wednesday, February 13, 2019. Rain is falling widely in Northern California and is expected to spread south. (Photo by Rich Pedroncelli/AP Photo)

Viking re-enactors representing the rival armies of the Vikings and Anglo-Saxons skirmish near Clifford’s Tower during the Jorvik Viking Festival on February 23, 2019 in York, England. The annual Jorvik Viking Festival held in York is recognised as the largest event of its kind in Europe. This year the festival remembers the role that the Viking women played during those turbulent times. (Photo by Christopher Thomond/The Guardian)

In this January 16, 2019, file photo, a homeless man sleeps on a median strip in New Delhi, India. In India, some 270 million people – nearly 22 percent of the country's population – live in poverty, making giveaways particularly attractive to voters. The Modi government in its interim budget in January announced farmers would be paid 6,000 rupees ($85) annually, benefiting as many as 120 million households and income tax relief to the middle class. (Photo by Altaf Qadri/AP Photo/File)

An Iraqi shi'ite muslim girl places a copy of the Koran on her head during the holy month of Ramadan at the Imam Ali Shrine, in the holy city of Najaf, Iraq on May 28, 2019. (Photo by Alaa Al-Marjani/Reuters)

Protesters shout as they hit a pole during ongoing anti-government protests in Beirut, Lebanon on November 19, 2019. (Photo by Andres Martinez Casares/Reuters)

Supporters of the PHTK presidential candidate Jovenel Moise strike zombie poses during a protest march demanding the resignation of interim President Jocelerme Privert in Port-au-Prince, Haiti, Tuesday, June 7, 2016. The electoral council of Haiti has decided to re-do a presidential election that a special commission determined was marred by fraud. (Photo by Dieu Nalio Chery/AP Photo)