In this July 25, 2015 photo, youth eat a cooked pig's head as they wait for the start of carnival in Santiago, Cuba. (Photo by Ramon Espinosa/AP Photo)

Cast member Shu Qi poses during a photocall for the film “The Assassin” (Nie yin niang) in competition at the 68th Cannes Film Festival in Cannes, southern France, May 21, 2015. (Photo by Eric Gaillard/Reuters)

A student protester throws a stone against a riot police vehicle during a demonstration to demand changes in the education system in Santiago, Chile, April 21, 2016. (Photo by Ivan Alvarado/Reuters)

Father Felix Mendoza, a Venezuelan Catholic priest, center, prays over a woman who cries, saying she is in physical pain, at a public hospital in Caracas, Venezuela, Tuesday, May 11, 2021, amid the new coronavirus pandemic. Father Felix has been visiting patients at the hospital to comfort the sick, for the last 20 years. (Photo by Ariana Cubillos/AP Photo)

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)

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)

The Villarrica Volcano is seen at night from Pucon town, Chile, July 12, 2015. Villarrica, located near the popular tourist resort of Pucon, is among the most active volcanoes in South America. (Photo by Cristobal Saavedra/Reuters)

Residents watch the ocean waves crash into the water front, after the passage of Hurricane Irma, in Cuba, Sunday, September 10, 2017. (Photo by Ramon Espinosa/AP Photo)