The medium tree finch 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. Because it has a very small range on a single island, and because of the introduction of a parasitic fly which kills the nestlings, the International Union for Conservation of Nature has rated the medium tree finch as "critically endangered".
Region
Galápagos Islands
Typical Environment
Restricted to the humid highlands of Floreana Island, especially in Scalesia forest and mixed shrub-woodland. It forages in the mid to upper canopy, also using edges, secondary growth, and some agroforestry mosaics. Nesting occurs in trees within relatively dense vegetation, where domed nests are sheltered from wind and sun. Habitat quality is affected by invasive plants and human-altered landscapes, which can fragment suitable territories.
Altitude Range
250–600 m
Climate Zone
Highland
Ease of Keeping
Beginner friendly: 1/5
A member of Darwin’s finches, the medium tree finch has a beak size intermediate between the small and large tree finches, suited to gleaning insects from foliage. It survives only on Floreana Island in the Galápagos and is critically endangered, primarily due to nestling mortality caused by the invasive parasitic fly Philornis downsi. Habitat degradation and introduced predators further threaten its already tiny population.
Temperament
solitary and territorial during breeding; otherwise loosely social
Flight Pattern
short rapid wingbeats with brief, undulating flights between perches
Social Behavior
Pairs form in the breeding season, with males advertising territories and building nest structures to attract females. The species constructs domed nests placed in trees, often concealed among foliage. Outside breeding, it may join small mixed flocks of other finches while foraging.
Migratory Pattern
Resident
Song Description
The male’s song is a simple series of clear, repetitive notes and short trills, varying slightly among individuals. Calls include sharp chip and tseet notes used for contact and alarm.
