Members of the San Francisco Gay Freedom Day Marching Band and Twirling Corps do their thing down San Francisco's Market Street, June 27, 1982. Police estimate the crowd to be 300,000 for the Lesbian/Gay Freedom Day parade and rally. (Photo by Carl Viti/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)

A masked reveller poses near Saint Mark's Square during the Venetian Carnival in Venice January 31, 2015. (Photo by Stefano Rellandini/Reuters)

A devotee pulls a chariot during the Hindu festival of Thaipusam in Singapore February 9, 2017. (Photo by Edgar Su/Reuters)

Models present creations by designer Guo Pei as part of her Haute Couture Fall/Winter 2019/20 collection show in Paris, France, July 3, 2019. (Photo by Regis Duvignau/Reuters)

President Woodrow Wilson speaks on telephone. Woodrow Wilson was the 28th U.S. President serving from 1913 – 1921. (Photo by Corbis)

Dressed up as Punxsutawney Phil, Marty Nagy, of Hallandale Beach, Fla., gives thumbs up to passers by before the start of the 12th annual Groundhog Day on Hollywood Beach, Tuesday, February 2, 2016, in Hollywood, Fla. The event, which featured breakfast and an ocean plunge, benefited the Hollywood Beach Lifeguard Competition Team. (Photo by Wilfredo Lee/AP Photo)

A tamed hawk attacks a rabbit during the traditional hunting contest outside the village of Nura, east from Almaty, Kazakhstan, February 13, 2016. (Photo by Shamil Zhumatov/Reuters)