Vampire Finch or Sharp-beaked Ground Finch (Geospiza difficilis) feeding on blood from Nazca Booby. (Sula granti)
ECUADOR. South America
On Darwin and Wolf Islands this species has developed the interesting feeding habit of pecking the base of the back feathers until the bird bleeds and drinking the blood. Normally they feed on bird lice but this is probably due to the pausity of food and water on these two islands.