One of the most extraordinary—and also one of the rarest—members of Darwin’s famous finches. Endemic to the Galápagos Islands, this bird is found only on Floreana Island, making it a true island specialist. Its appearance is modest: males are gray-brown with darker wings and pale underparts, while females are usually duller, blending into the forest canopy.

What makes the medium tree finch truly unique is its extreme rarity. It is restricted entirely to Floreana’s humid highland forests, making it the only Darwin’s finch confined to a single island. Its narrow distribution has made it incredibly vulnerable, and today it is listed as Critically Endangered by the IUCN. One of the greatest threats to its survival comes from the parasitic fly Philornis downsi. The fly lays its eggs in finch nests, and its larvae feed on the blood and tissues of nestlings, often killing entire broods. This has caused dramatic declines in the population of medium tree finches, making them one of the most threatened birds in the Galápagos. Habitat loss and invasive species like rats and cats also add to the pressures.

Ecologically, the medium tree finch plays an important role as a forest insect hunter. Like its close relatives in the genus Camarhynchus, it is arboreal, foraging mostly in the tree canopy. Its medium-sized bill allows it to target insects of a size range that overlaps with, but does not directly compete against, those of the small and large tree finches. This is a classic case of adaptive radiation, where closely related species evolve slightly different niches to reduce competition.

Distribution

Country

Population est.

Status

Year

Comments

Ecuador

1,000-2,500

Official estimate

CR

2018

Galápagos