A water drop magnifies this feather's details... i.e., its barbs and barbules.
A typical vaned feather features a main shaft, called the rachis. Fused to the rachis are a series of branches, or barbs; the barbs themselves are also branched and form the barbules. These barbules have minute hooks called barbicels for cross-attachment. [...] Feathers insulate birds from water and cold temperatures.