The Common Cactus Finch lives in the dry zone of the Galápagos and often uses prickly pear cactus for food. Its long, pointed bill helps it take food from the cactus.
In breeding plumage, the male is mostly black, with pale areas on the rear, center of the belly, and scaled undertail coverts. The female is gray-brown above with a pale, streaked underside. Bill color changes with breeding status.
It feeds on Opuntia flowers, nectar, pollen, and fruit, as well as seeds and insects. Males display in front of a nest built in an Opuntia pad; females incubate and both parents feed the chicks.
An extinction-risk assessment has not been added yet.