Vampire finches live on the Galapagos Islands: due to the harsh living conditions in the archipelago, they began to attack other birds and drink their blood. The species is called Darwin’s finches and is featured in the BBC’s Perfect Planet.
Darwin’s finches are native to the Galapagos Islands, a volcanic archipelago about 1,000 km off the coast of Ecuador. The islands are a region of rich biodiversity in part because of their isolation. Organisms that somehow end up in the Galapagos Islands must adapt to the harsh conditions in order not to die out
Finches in the process of evolution, finches received such a shape and size of the beak that they can eat a variety of foods. For example, the cactus finch has a long, thin beak, with which the bird is able to consume nectar from the cactus flowers. Some species have beaks that crush seeds better, while others are better at eating insects or plants.
Vampire finches are found only on the northern islands of Wolf and Darwin in the Galapagos archipelago. Fresh water is extremely rare there, and some of the food may simply disappear during the dry season.
About 500 thousand years ago, finches settled on these islands, where they were forced to coexist with large seabirds, such as boobies. At first, finches began to eat parasites living in the skin and feathers of boobies. Both species gained in this case: boobies got rid of parasites, and finches got food.
But the search and removal of parasites ultimately led to numerous skin wounds on the bodies of boobies, which Darwin’s finches took advantage of. They have learned to pierce the skin at the base of young feathers to gain direct access to blood, no longer needing parasitic insects. Thus, the finches took advantage of an alternative food resource, the blood of boobies, and earned themselves the nickname “vampire finches.” Today, blood makes up 10% of all food that Darwin’s finches consume.