The feathers on this hummingbird’s throat are surprising. One minute they’re bright red, the next, black. This is known as iridescence, a common, showy feature of many birds’ plumages, from hummingbirds to starlings to jays to ducks. Iridescence doesn’t exist as a pigment—it is a structural color created by light striking the feathers. In each iridescent feather, keratin, melanin, and air are arranged in such a way that the appearance of the feather changes at different viewing angles.

This video accompanies Chapter 4, Feathers and Plumages, Handbook of Bird Biology, 3rd Edition from the Cornell Lab of Ornithology and Wiley Publishing.

Recorded by Luke Seitz, Macaulay Library