- Order: Passeriformes
- Family: Thraupidae
South Plaza, Santa Cruz, Galápagos, Ecuador; 19 February 2008 © Roger Ahlman
Sometimes known only as the Cactus Finch, although there is a larger billed species, the Large Cactus-Finch that one needs to differentiate it from. The Common Cactus-Finch is widespread, being found on most of the larger islands in the Galapagos archipelago. It is one of the Geospiza, or ground-finch group, although both cactus-finch species have bills that are longer than that of the other ground-finches. The bill of the Common Cactus-Finch is in fact spike-like in shape, thick at the base but long and tapering to a good point. The cactus-finches also differ from other Geospiza in foraging heavily on the flower and seeds of Opuntia (prickly pear) cactus in the lowland arid zone. Overall approximately a third of the diet are seeds from Opuntia cactus, and another third is made up of flowers while the rest includes other small seeds, and insects. They not only forage on the Opuntia, they also usually found in or near it, and prefer to build their nests in a denser part of the cactus itself. The Common Cactus-Finch is found on islands with various other ground-finches, but it never is found with the Large Cactus-Finch.
. 2010. Common Cactus-Finch (Geospiza scandens), Neotropical Birds Online (T. S. Schulenberg, Editor). Ithaca: Cornell Lab of Ornithology; retrieved from Neotropical Birds Online: http://neotropical.birds.cornell.edu/portal/species/overview?p_p_spp=632396