If you watch a bird for long, you will see it working carefully through its feathers with its beak. This is preening — and far from being a nervous habit, it is essential, healthy feather care.
What preening does
Preening is how birds keep their feathers in flying condition. Running each feather through the beak cleans off dirt and dust, removes parasites, and re-aligns the tiny barbs so the feather zips smoothly back together — vital for insulation and flight. Birds also nibble away the waxy sheaths from newly grown feathers as they preen.
Spreading preen oil
Most birds have a preen gland near the base of the tail that produces an oil. During preening, a bird collects this oil on its beak and works it through its feathers, which helps keep them waterproof, flexible and in good condition. It is a big part of why a healthy bird looks so sleek.
A sign of a happy, healthy bird
Regular preening is a good sign — a relaxed, comfortable bird preens calmly, and pairs often preen each other as a bond of trust. The thing to watch for is the opposite extreme: obsessive, damaging over-preening or feather plucking, which points to a problem and is worth a vet's attention.