High Quality Content by WIKIPEDIA articles! The Warbler Finch (Certhidea olivacea) is a species of bird, one of Darwin`s finches in the tanager family Thraupidae. Sometimes classified in the family Emberizidae, more recent studies have shown it to belong in the tanager family. It is the only member of the genus Certhidea. When Darwin collected it in 1835 during the Beagle survey expedition he mistakenly thought it was a wren, but on return to England he was informed in March 1837 by the ornithologist John Gould that the bird was in the group of finches.