Christmas baubles shaped as Santa Clauses wearing protective masks are pictured amid the coronavirus disease (COVID-19) pandemic in Eichenau, Germany, November 26, 2021. (Photo by Michaela Rehle/Reuters)

A schoolgirl walks on an under-construction railway track at Navapura, on the outskirts of Ahmedabad, November 29, 2019. (Photo by Amit Dave/Reuters)

Blaze, 8, from Swindon, is covered from head to toe as he plays in the mud at Weston-super-Mare beach on August 4, 2019, as the tide recedes and the huge expanse of mud flats cover the beach where holidaymakers enjoy splashing around. (Photo by Ben Birchall/PA Images via Getty Images)

People look at a black bear at the Chengdu zoo amid the coronavirus outbreak on March 26, 2020 in Chengdu, Sichuan Province of China. (Photo by Wang Lei/China News Service via Getty Images)

A mobile phone showing the time at noon, is displayed for a photo in front of an almost empty road with low traffic, during the coronavirus disease (COVID-19) outbreak, in Wuhan, Hubei province, China, March 31, 2020. (Photo by Aly Song/Reuters)

A farmer carries a bundle of wheat after harvesting it from a field in the Gharbia Governorate, as Egypt ramps up efforts to slow the spread of the coronavirus disease (COVID-19), Egypt on May 14, 2020. (Photo by Mohamed Abd El Ghany/Reuters)

Television personality Farrah Abraham (C) enjoys adult entertainment as she hosts the VIP Back Door Key party at the Crazy Horse III Gentlemen's Club on August 4, 2017 in Las Vegas, Nevada. The newly launched VIP membership program offers patrons exclusive entrance to the club through the back door. (Photo by Bryan Steffy/WireImage)

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)