This species is only found on Floreana Island at elevations above 250m in moist highland forest habitat. The medium tree finch (Camarhynchus pauper) is a critically endangered species of bird in the Darwin's finch group of the tanager family Thraupidae.It is endemic to the Galápagos Islands where it is only found on Floreana Island.Its name is derived from the fact that the bird's beak is intermediate in size between that of the small tree finch and the large tree finch.

All of Darwin’s Finches are sparrow sized and similar in appearance with grey, brown, black or olive feathers.
The Medium Tree-finch (Camarhynchus pauper) is a critically endangered species of bird in the Darwin's finch group of the tanager family Thraupidae. A fairly large, parrot-billed Galápagos finch. This finch is threatened by a type of fly that lives in its nest and feeds on the blood and tissue of the chicks. Galapagos Finches/Darwin’s Finches There are 14 different species of Darwin’s Finches with 13 of the species resident on the Galapagos islands.
Darwin’s Finches are very fearless and very noisy. This finch is fairly rare as it may only be found on Floreana Island. Specifically, it is seen in the highlands on this island. Mangrove Finch, found only on Isabella Island, numbers 40-80 adults, while Medium Tree-finch occurs only on Floreana Island and has a population of 600-1,700. The Large Tree-Finch is also noted to be on Floreana, but it is either very rare there now or it is so difficult to separate from the Medium that sightings are few. Large Tree-Finch has larger and more bulbous bill. Small Tree-Finch has slightly smaller bill and body. The fly is considered the “most significant threat” to Medium Tree-finch, and it’s also a “significant threat” to the Mangrove Finch. Medium tree finch. Healthy hybrid Darwin's finch foraging and extracting P. downsi parasite from a finch nest. Darwin’s Finches are named after the great biologist […] Criteria: B1ab(v) Click here for more information about the Red List categories and criteria Justification of Red List category This species qualifies as Critically Endangered as it has a very small range on a single island, and recent information suggests that it is declining rapidly owing to the effects of the dipterid parasite Philornis downsi. Male has a black head and back, and a yellowish belly with a varying amount of dark streaking. Identification is much easier when more than one species is present to allow direct comparison. Distribution / Range. The Medium Tree-Finch is less abundant than the more common Small Tree-Finch on Floreana, and the two are usually found together. Its beak size is similar to that of the large tree finch. Female is tan with a whitish or yellowish belly, and brown streaks on the underparts.