Darwin’s Finches are small landbirds with generally dull black, brown or olive, often streaky, plumage; short tails; and short rounded wings. Their bills vary greatly in size and shape ( a fact that was instrumental in inspiring Darwin’s thinking in relation to the theory of evolution). Darwin’s finches are found in all the habitats on the Galapagos. Identification can be difficult due to the variation within each species and the occurrence of hybrids.
The species fall into three genera: Geospiza, Camarhynchus, and Certhidea. The Geospiza are the ground and cactus finches and are entirely black. The Camarhynchus are the vegetarian and tree finches with the adult males having black heads and olive or brown streaked bodies; the woodpecker and mangrove finches which are mainly brown or grey. The Certhidea are the warbler finches and are mainly brown and grey.
The Cactus Finch shown above is a locally common resident. The adult male is wholly black with white tipped undertail -coverts. The female and immature Cactus Finch is brown and heavily streaked around the head and neck. The most frequent call is a loud, ringing “ teur-lee, teur-lee,” and occasionally sings in flight.