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)

View of a group of ostriches, in the gardens of the Palacio do Alvorada, in Brasilia, Brazil, 02 June 2020. The ostrich is the largest and heaviest bird in the world. When the chicks hatch they are between 25 and 30 cm tall, weighing about 900 grams. (Photo by Joedson Alves/EPA/EFE/Rex Features/Shutterstock)

Villagers play traditional games as they take part in a Chyrachka rite during the Shrovetide celebration in the village of Tonezh, some 280 km of Minsk, on March 10, 2019. Chyrachka is a kind of birds that live in this area. (Photo by Sergei Gapon/AFP Photo)

A Common Blue Morpho butterfly lands on the arm of Garbiella as it and hundreds of other butterflies from around the world fill the bird aviary for the next month at the San Diego Zoo Safari Park in San Diego, California March 13, 2015. Called the Butterfly Jungle, the exhibit has over 30 species of butterflies. (Photo by Mike Blake/Reuters)

A goose has terrorized students at the University of Warwick, Coventry, UK, on May 22, 2013. The bird built its nest near a block of student apartments and attacks anyone who goes near the nest. (Photo by Caters News/The Grosby Group)

A man transports chicken on a motorscooter to the chicken market in Kathmandu, Nepal, 07 February 2023. Cases of bird flu, or avian influenza, infections have been confirmed in three places in the Kathmandu Valley, according to the Ministry of Agriculture and Livestock Development (MoALD), causing a drop in sales of chicken in the valley after the spread of the flu news. (Photo by Narendra Shrestha/EPA)

One of ten little spotted kiwi is released on Motuihe Island, a conservation pest-free island close to Auckland, on March 21, 2009 in Auckland, New Zealand. Eventually up to 40 endangered kiwi birds will be relocated to the island. (Photo by Hannah Johnston/Getty Images)

The Resplendent Quetzal (Pharomachrus mocinno) is a bird in the trogon family. It is found from southern Mexico to western Panama (unlike the other quetzals of the genus Pharomachrus, which are found in South America and eastern Panama). It is well known for its colorful plumage.