A masked Bulgarian dancer takes part in the second competition day of the 24th International Festival of Masquerade Games “Surva” in the town of Pernik, Bulgaria Saturday, January 31, 2015. Some 5,000 people are expected to take part in the three-day festival devoted to an ancient Bulgarian pagan rite. Surva is performed by costumed men, some in sheepskin, or other colorful garments, bells and masks, who walk around and dance to scare away the evil spirits, in hope to provide a good harvest, health, fertility, and happiness. (Photo by Valentina Petrova/AP Photo)

A fan cosplays as Aloy from Horizon Zero Dawn during the 2017 New York Comic Con, Day 4 on October 8, 2017 in New York City. (Photo by Roy Rochlin/WireImage)

A staff member (R) looks on next to a cake, which was baked in the shape of a muscular man, for customers to try for free during a promotional event of a cake store in Shenyang, Liaoning province, China, December 6, 2015. (Photo by Reuters/Stringer)

A man plays with his pet goat while taking a bath to cool off in a canal during hot and humid weather in Lahore, Pakistan May 30, 2018. (Photo by Mohsin Raza/Reuters)

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 secretive indri (Indri indri) of Madagascar, the largest living lemur. It is also critically endangered and highly evolutionarily distinct with no close relatives, which makes its branch one of most precarious on the mammal evolutionary tree. In the likely event that the indri goes extinct, we will lose 19m years of unique evolutionary history from the mammal tree of life. (Photo by Pierre-Yves Babelon/Aarhus University)

A general view shows the part of the skyline of Dubai covered in an early morning fog on October 5, 2015. (Photo by Rene Slama/AFP Photo)

A stroller walks his dogs in an autumnally colored forest in Cuxhaven, nothern Germany on November 7, 2018. (Photo by Patrik Stollarz/AFP Photo)