What does molting mean?

The story behind the answer

Molting means replacing old feathers. Birds periodically shed worn or damaged feathers and grow new ones to keep flight efficient, stay insulated and waterproof, and refresh breeding plumage. It’s not shedding skin like snakes (ecdysis), not losing fur or hair, and not migration.

Many species molt once or twice a year; some do a partial molt, others a complete one. Ducks and penguins may undergo a rapid, synchronous molt that leaves them temporarily flightless. Molting is energy-intensive and timed with food availability and day-length cues via hormones. Memory tip: “Molt = molt-feather,” as in swapping out feathers for fresh ones.