Inaccessible Island Finch Nesospiza acunhae

A highly variable finch with three distinct forms in the process of diversifying. The massive large-billed form is known as “Dunn’s Finch”; the two smaller forms with petite bills are a drab olive lowland form (Lowland Finch) and a bright yellow highland form (Highland Finch). Females of all forms are smaller, duller, and more streaked than males. Endemic to Inaccessible Island, where it is the only finch. Lowland form prefers grassy coast and cliffs, highland form prefers the plateau, and Dunn’s form prefers taller fruit-bearing woodland. In all forms, male sings a 3-note “whit-it-teeu” and the female whistles; Dunn’s form sounds deeper and slower than the others.