10 of the World’s Smallest Birds

Researchers are still trying to figure out even the basic habits of Esmeraldas Woodstar — a highly localized breed of hummingbird that’s the tiniest in South America. Despite measuring only 2.5 inches in length, males of this species stand out due to their brilliant purple throats and the green markings along their bodies that resemble a tiny vest. These birds can be found in deciduous forests throughout Ecuador, and they have a preference for wooded areas at higher altitudes.

The problem is that they can be very hard to find in the wild. The species was thought to be extinct from 1912 until the next spotting of one in 1990 — but even now they’re rarely seen outside of breeding season. Where these birds go for the rest of the year remains a mystery for now. It’s unfortunately also an endangered species that’s threatened by the destruction of its habitats due to logging.