Galapagos Darwinism and birdlife - Other finch species
The miscellaneous finches are in many ways the most interesting, for here we find the most variety in behavioral adaptation.
Woodpecker finch
(Geospiza pallida), one of the very few birds in the world to use "tools", in this case a twig or cactus spine, to aid in feeding. The small yellowish finch will seek out and select this implement to pry insects or their larvae out of small holes in cactuses, or from beneath bark. They have even been seen to carry the tool from tree to tree, as if it has proven its value as a favorite. The woodpecker finch nests in the highlands of the major central islands including San Cristóbal, Santa Cruz, Santiago, Pinzón, Isabela and Fernandina.
Mangrove finch
(G. heliobates), a light colored bird with narrow bill that is found on Isabela and Fernandina. Rising sea levels due to global warming post a direct threat to the survival of this species, since it nests in the endangered mangrove forests.
Warbler finch
(G. olivacea) is the smallest of Darwin's finches, and in the size and shape of its bill, coloration and song it earns its name. Even Darwin was certain it was a warbler, but John Gould -- who catalogued Darwin's collection upon the latter's return from the voyage of the Beagle -- identified it by anatomy correctly as a finch. Despite its unique role in the catalog of Darwin's finches, it is the most wide-spread species, nesting in the highlands of the large islands but being found through all quarters of the archipelago.

