Birds molt, or shed old feathers and grow new ones, once or twice a year. The length of the molting period depends on the species of bird. Small birds like finches may only take a few weeks to molt while larger birds like hawks can take up to six months. Here are some quick answers about how long birds molt for:
- Small songbirds molt for 2-4 weeks
- Backyard birds molt for 4-8 weeks
- Seabirds molt for 2-3 months
- Birds of prey molt for 4-6 months
The molting process is carefully timed for each species to ensure they can still fly and avoid predators while renewing their plumage. Birds will often molt just after breeding season when they don’t need bright colorful feathers for attracting mates. The specific molting duration allows them to regrow a complete set of feathers before migration or the next breeding season.
Duration of Molting by Bird Group
Here is a more detailed look at how long different groups of birds molt for:
Songbirds
Small passerine songbirds like finches, warblers, and sparrows have very quick molts of only 2-4 weeks. They often do a complete molt where all their feathers are replaced. Some songbirds molt just their body feathers first and then the flight feathers later which extends the molting period. Tropical songbirds that don’t migrate may molt twice a year while temperate species just molt once in late summer/early fall.
Backyard Birds
Many common backyard birds like chickadees, titmice, and jays molt for 4-8 weeks. Some backyard birds like mockingbirds and thrushes may take up to 12 weeks to complete their molt. Backyard birds time their molt to finish before migration or winter weather sets in.
Waterfowl
Ducks, geese, and swans undergo a complex multi-year molting process. They lose and regrow their flight feathers over a period of 1-3 months every year. However, they molt their body feathers much more frequently, every 3-6 weeks. They are vulnerable to predators while molting their wing feathers and will stay on the water or avoid flying during this time.
Wading Birds
Herons, egrets, ibises, and other wading birds molt for around 2 months. However, some like the wood stork take 4-5 months to complete their molt. Wading birds begin molting right after breeding and nesting is complete. They grow special molting plumage that is whiter and has longer feathers on the head, neck, and back.
Seabirds
Seabirds have a very prolonged and complex molting process. It may take 2-3 months for an albatross or frigatebird to molt all its feathers. Seabirds often lose their flight feathers sequentially over many months to always maintain some ability to fly and avoid predators. They nest on isolated islands or cliffs to safely molt.
Birds of Prey
Hawks, eagles, owls, and other raptors have very long molting periods of 4-6 months. They replace their feathers sequentially starting in late summer. Raptors will stay perched and avoid hunting and flying while molting their wing and tail feathers. Their body feathers may molt first while flight feathers are replaced later.
Gamebirds
The molt duration for pheasants, quail, grouse, and wild turkeys ranges from 8-12 weeks. These birds stay hidden in brushy habitat while molting to avoid being caught by predators. Some gamebirds may do a double molt, first replacing body feathers and later renewing their wing and tail feathers.
When Do Birds Molt?
Most birds only molt once a year. Here are the common molting seasons for various bird groups:
Bird Group | Molting Season |
---|---|
Songbirds | Late summer & early fall |
Wading birds | Mid to late summer |
Raptors | Mid summer to early fall |
Waterfowl | Mid summer through fall |
Seabirds | Fall and winter |
Gamebirds | Late summer |
The exact timing depends on when breeding concludes and needs to be timed well in advance of migration for migratory species. Tropical and Southern Hemisphere birds may molt more frequently, before the rainy or breeding seasons.
Major and Minor Molts
In addition to the major annual molt, some birds may have a minor molt at other times of year:
- Finches: Molt body feathers again in late winter
- Falcons: Replace some feathers again in spring
- Tropical birds: Can molt before rainy or breeding seasons
- Penguins: Annual complete molt lasts 2-5 weeks
- Parrots: Molt continuously throughout the year
The minor molts are much shorter than the major annual molt and renew only select plumage. Frequent minor molts help tropical birds maintain bright breeding plumage and replace feather damage from their year-round lifestyle.
Other Factors Influencing Molt Duration
Here are some other elements that account for differences in molting duration:
- Size of bird – larger birds take longer to replace more feathers
- Age – younger birds may molt faster than adults
- Health – sickness or poor nutrition can extend molt
- Captivity – captive birds may molt unusually early or more frequently
- Location – northern birds need to molt faster before winter
Molting is carefully programmed into a bird’s annual cycle and allows time for complete feather replacement. However, various internal and external factors can speed up or slow down an individual bird’s molt.
Conclusion
All birds periodically molt and renew their plumage, but species have adapted to molt at different times of year and for varying durations. Small songbirds can molt in just 2-4 weeks while a large raptor may take 4-6 months to replace all feathers. The molting duration is precisely scheduled to avoid risks like feather damage, inability to fly, or being caught by predators. Understanding the molt cycle helps provide insights into the seasonal rhythms and health of both wild and captive birds. Providing birds adequate nutrition and refuge during this energy-intensive process allows them to successfully complete their annual molt.