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)

Iberian lynx Mistral jumps in a field after being released by Portugal's Minister of Environment Joao Matos Fernandes (unseen) and others in the Mount Milhouro (Herdade da Cela) region in Mertola, Portugal, 13 May 2016. Mistralis the 18th lynx bred in captivity released since late 2014. (Photo by Nuno Veiga/EPA)

Budgies feed on seeds from a local visitor's hands at Ocean Park in metro Manila, Philippines September 10, 2016. (Photo by Romeo Ranoco/Reuters)

A man plays in front of a wave crashing into Beirut's Corniche, a seaside promenade, as high winds sweep through Lebanon ahead of an impending storm January 6, 2015. (Photo by Jamal Saidi/Reuters)

Snow covers roofs, streets and the Charles River following a winter blizzard in Boston, Massachusetts January 28, 2015. A powerful blizzard struck Boston and surrounding New England on Tuesday, leaving some 4.5 million people grappling with as much as three feet of snow and coastal flooding. (Photo by Brian Snyder/Reuters)

A woman poses for pictures with skulls made of cardboard placed on an altar next to the San Francisco church in Mexico City during the celebration of All Souls Day on November 2, 2015. (Photo by Yuri Cortez/AFP Photo)

A photographer takes pictures near an inflated Master Yoda character hot air balloon during the 33rd annual QuickChek New Jersey Festival of Ballooning at Solberg Airport Friday, July 24, 2015, in Readington, N.J. The festival which runs through Sunday, July 26, 2015, will feature as many as 100 balloons, including many large, shaped balloons of Darth Vader, an American Flag, a giant whale, a Panda Bear, and a baby dinosaur. (Photo by Mel Evans/AP Photo)

The first red panda cub was born on May 30 in zoo Zlin. Zoologist Roman Vrzal holds a male of red panda. The Red panda is pictured in Zlin, Czech Republic, August 20, 2014. (Photo by Dalibor Gluck/CTK)