What Permits the Feather to "Zip" and "Unzip

Question

What permits the feather to "zip" and "unzip"?
A)The cohesive force of water molecules
B)Barbules and hooks
C)Oil from skin glands sticks the vanes together
D)Magnetic attraction due to charges built up from the feathers rubbing against each other
E)Bird saliva acting as a temporary glue

Accepted Answer

Barbules and hooks allow the individual barbs on a feather to interlock, creating a zipper-like effect that keeps the feather aligned and aerodynamically effective. These same hooks allow the feather to be easily "unzipped" so that a bird can preen and maintain its feathers.