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- Geospiza fortis
Plumage varies from black (presumably in males) to mostly brown with streaks on underside. Bill varies from black to pink to yellow. The main distinguishing factor is shape of bill, with curved upper mandible with straighter lower mandible, and with the upper mandible longer than the height at base of the bill. Note that the bill size varies among islands, and some of the larger islands have two populations of Medium Ground Finch, one large- and one relatively small-billed.
Forest and shrubland