Can birds still fly while molting?

Most songbirds molt their flight feathers gradually and symmetrically, a few at a time on each wing, so they remain fully capable of flight throughout. Some waterfowl, including ducks and geese, are an exception: they molt all their flight feathers at once and become flightless for several weeks, typically timing this vulnerable period to coincide with abundant food and reduced need to travel.

Why do some birds look different in summer and winter?

Many species undergo two molts a year, producing a brighter breeding plumage in spring through a partial molt, then replacing it with a duller, more camouflaged non-breeding plumage after the breeding season — a pattern especially pronounced in many wader and duck species where males in particular look strikingly different between seasons.

Bird Atlas

Molt in Birds

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Molt is the periodic shedding and replacement of feathers, essential for flight efficiency, insulation, and — in many species — seasonal changes in plumage color.

Why birds molt

Feathers are dead structures once fully grown — they cannot repair themselves — so they must be periodically replaced as they wear down from flight, sun exposure, and daily abrasion. Molt is this replacement process: old feathers are shed and new ones grow in from the same follicles, usually following a specific, orderly sequence rather than falling out all at once. Most adult birds molt at least once a year, typically after the breeding season, when the energetic demands of raising chicks have eased but before the stresses of migration or winter begin.

Flight feathers are molted with particular care, since losing too many at once would seriously impair flight. Songbirds like the common starling molt flight feathers gradually and in a fixed, symmetrical sequence on both wings, keeping enough intact feathers to fly normally throughout the process. Ducks and geese, including the mallard, take the opposite strategy: they drop all their flight feathers within days of each other and become flightless for two to four weeks, a vulnerable period they typically time to coincide with abundant food and reduced predation pressure, often on open water offering some safety from land predators.

Seasonal plumage change

In many species, molt does double duty: it not only replaces worn feathers but also produces a different-looking plumage. A pre-breeding molt in late winter or spring can bring in brighter, more conspicuous feathers used in mate attraction and territory display, while a post-breeding molt later in the year replaces this with duller, better-camouflaged plumage for the months outside the breeding season. This is most dramatic in many duck species, where males spend a period in an inconspicuous "eclipse" plumage that closely resembles the female before molting back into their bright breeding colors ahead of the next season.