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The medium tree finch is a Darwin’s finch found on just one island — Floreana — and nowhere else on Earth. Critically endangered, this small grey-brown bird is fighting the same parasitic fly that threatens so much of the islands’ wildlife. Here is what it is, where it lives, and why it matters.
Medium tree finch at a glance
- Scientific name: Camarhynchus pauper
- Where: Floreana Island only — nowhere else on Earth
- Look: small, fast, greyish-brown with pale underparts
- Diet: insects gleaned from foliage and bark
- Main threat: the parasitic fly Philornis downsi
- Status: Critically Endangered
What is it?
The medium tree finch (Camarhynchus pauper) is a Critically Endangered Darwin’s finch, endemic to Floreana Island alone. It is small, fast and mostly greyish-brown, with white and yellowish underparts that help it melt into the foliage; males develop a partial dark hood. In size and bill it sits between the small and large tree finches. Planning a trip around what you want to see? Tell us your dates and we’ll send a free quote within 24 hours.
One island, one finch
What sets the medium tree finch apart is its tiny range. It lives only on Floreana, one of the nine major islands, and only in the moister highlands at that. If anything goes wrong on that one island, the whole species is at risk — which is exactly the problem it now faces.
Why it is critically endangered
The biggest threat is the invasive parasitic fly Philornis downsi, whose larvae feed on chicks in the nest and kill many of them before they fledge. Add habitat loss on inhabited Floreana, and numbers have fallen sharply. Conservationists are tackling the fly and protecting nests, and restoring Floreana’s ecosystem is a major focus for the islands’ future.
What it eats and where it lives
Like the other tree finches, the medium tree finch is mostly an insect-eater, gleaning bugs from foliage and bark with some plant matter. Its home is the humid highland forest of Floreana — the green, misty zone where most of the island’s remaining native birdlife survives. These medium tree finch facts underline how dependent it is on healthy Floreana forest. You can see this on our 5-day island hopping itinerary.
6-Day Galapagos Land Tour Santa Cruz + Isabela Highlights
From $1,150 p.p.
- Sleep in island hotels, not a cruise cabin
- Local naturalist guides
- Flexible day-by-day island hopping
Where to see it
There is only one place to try:
- Floreana highlands — the only place on Earth it lives, in the moist forest zone.
- With a guide — who knows the bird and the remaining forest patches.
- Combine with Floreana’s history — the island’s human story is as fascinating as its wildlife.
Quick facts
A few more medium tree finch facts:
- Its scientific name is Camarhynchus pauper, an endemic Darwin’s finch.
- It lives only on Floreana Island, nowhere else on Earth.
- It is Critically Endangered.
- Its main threat is the parasitic fly Philornis downsi.
- It is an insect-eater of the moist Floreana highlands.
Camarhynchus pauper, a one-island finch
The scientific name camarhynchus pauper belongs to a tree finch with the smallest world of any in the family: it lives on Floreana and nowhere else on Earth. Intermediate in size and bill between the small and large tree finches, it would be hard to separate from its relatives by looks alone — but it never has to be, because no other tree finch shares its island. Location is identity for this bird.
That single-island range is also its great weakness. A species spread across many islands can absorb a disaster in one place; one confined to a single patch of highland forest cannot. Everything that threatens Floreana threatens this finch directly, which is why it has become a focus of some of the most intensive conservation work in the archipelago.
Medium tree finch diet and Floreana habitat
The medium tree finch diet is much like that of its relatives — insects and larvae gleaned from foliage and bark, with some plant matter — gathered in the cool, damp uplands. The medium tree finch habitat is the moist highland forest of Floreana, the green, misty zone where most of the island’s surviving native birdlife clings on. Outside that forest the bird simply cannot live.
Restoring and protecting that highland forest is therefore the same thing as protecting the species. Plans to remove invasive predators from Floreana and rebuild its ecosystem carry real hope, not only for this finch but for several other species that share its shrinking home.
Medium tree finch facts and the Philornis fight
The hardest of the medium tree finch facts is its status: Critically Endangered, with the invasive parasitic fly Philornis downsi its chief killer. The fly’s larvae feed on chicks in the nest and kill many before they fledge, and on an island with so few birds left, that toll is devastating. Habitat loss on inhabited Floreana adds further pressure.
Conservationists are fighting back on several fronts — researching ways to control the fly, protecting nests, and planning the island-wide restoration that could finally give the species room to recover. Small, plain and easily overlooked, it has become a symbol of how fragile a one-island bird can be, and of how much careful effort it takes to keep one alive.
This is one of the rarest finches on Earth, and you can only meet it in a single place: the highland forest of Floreana Island. It lives nowhere else, and its whole world is a shrinking patch of moist Scalesia woodland on one inhabited island. That tiny range, combined with a steep decline, has earned it a place on the Critically Endangered list — among the most threatened of all Darwin’s finches.
Its greatest enemy is not hunger or drought but a fly. The larvae of the introduced parasitic fly Philornis downsi infest the nests, feeding on the blood of the helpless chicks and killing many before they ever fledge. Combined with habitat loss on a farmed island, this has pushed the population dangerously low, and researchers now wrap conservation around every nesting season, treating nests and trialling ways to control the fly.
In the hand it is the awkward middle child of the tree finches, intermediate in size and bill between its small and large relatives, and on Floreana that is exactly how birders identify it — by being the only tree finch on the island rather than by any single feature. Like its cousins it gleans insects and spiders from foliage and bark high in the canopy, with a little fruit and soft plant matter to round things out.
Frequently asked questions
Where does the medium tree finch live?
Only on Floreana Island, in the moist highland forest, and nowhere else on Earth.
What is its scientific name?
Camarhynchus pauper, a Critically Endangered Darwin’s finch.
Why is it endangered?
Mainly the invasive parasitic fly Philornis downsi, whose larvae kill chicks in the nest, together with habitat loss on Floreana.
What does it eat?
Mostly insects gleaned from foliage and bark, plus some plant matter.
How is it different from the other tree finches?
It is intermediate in size and bill, but the surest clue is location: it is the only tree finch on Floreana.
What do medium tree finches eat?
Mainly insects and spiders gleaned from foliage and bark high in the canopy, plus a little fruit and soft plant matter. They feed in the trees on Floreana, the only island where this critically endangered finch survives.
A finch on the edge
The finch shows how fragile a one-island species can be. Its fate is tied to the health of Floreana’s forests — a reminder that protecting a single island can mean saving a whole species.
Read more at the Galapagos Conservation Trust, or meet the whole family in my guide to Darwin’s finches and the equally rare mangrove finch.
