Takeaway: Ever seen a bird that seems to have lost many of its feathers? This could be molting, a natural process that helps birds stay healthy and fly efficiently.
Feathers are crucial for birds as they seek to regulate their body temperature. Feathers can be used to trap heat in cold weather or shed warmth when it’s hot. They also contain oil secreted by the preen gland that helps them become waterproof, preventing them from becoming waterlogged and heavy, and they are also essential for flight, display, and camouflage.
But what does it mean when we see a bird that has lost many of its feathers, especially on its head? If you’ve ever seen a scruffy-looking or nearly naked bird in your smart bird feeder and wondered if it was sick or injured, you’re not alone. But don’t panic just yet–that rough-looking bird is likely going through molting, a natural process that helps birds stay healthy and fly efficiently.
Let’s look at molting in more detail to understand what it is, why it takes place, and why some birds take it to wild extremes.
What Is Molting?
Molting is the process of shedding old feathers and growing new ones. Feathers don’t last forever–they wear down due to sunlight, preening, weather, and everyday use. Because of this, birds periodically shed old feathers to make room for new ones.
How often does this happen? Most birds molt once or twice a year. Most of the time, it takes place in a controlled, symmetrical fashion–feathers are lost and regrown gradually so the birds can continue to fly, forage, and evade predators.
Why Do Birds Molt?
Birds molt for several reasons:
- Feather maintenance: Old, worn feathers reduce flight efficiency. They lack proper shape, aerodynamic properties, and wing area.
- Seasonal needs: Some birds have different colored feathers for breeding and non-breeding seasons.
- Growing up: Juvenile birds molt their baby feathers as they grow into adults.
- Health and hygiene: Old feathers can be damaged or have parasites; shedding them keeps birds in good condition.
What Is Catastrophic Molting?
While most birds molt in stages, some undergo a process called catastrophic molting. In this event, large groups of feathers, or even all of a bird’s feathers, shed at once. This renders the birds temporarily flightless. While it sounds bad (and looks terrible), it’s a normal part of their life cycle.
- Blue jays can look bald: Some blue jays undergo a molt that makes their heads look totally bald and reveals gray skin underneath. It’s harmless and temporary.
- Goldfinches change their color: The American goldfinch molts twice a year–once in the spring to change to bright yellow breeding feathers, and again in the fall to switch to a duller brown.
- Northern cardinals can also look bald: Cardinals can appear raggedy in late summer due to molting. Some may lose all their head feathers at once, making them look like vultures.
- Most songbirds don’t molt: Most songbirds do not undergo catastrophic molting because it would leave them flightliess–and being unable to fly would be life threatening.
- Hummingbird molt is strategic: You might notice hummingbirds on your FeatherSnap hummingbird cam that lose feathers gradually. This preserves their ability to fly and access nectar while avoiding predators.
When Do Birds Molt?
Birds usually molt once or twice a year. The main molting period is in the late summer or fall, after the breeding season has taken place. Some birds may also molt in the spring to replace head or body feathers.
- Timing depends on the species
- Habitat, season, and bird age/life cycle influence molting patterns
- Different species of birds undergo partial and complete molting
Are Bald Birds Sick?
If you see a bird that is bald or looks scraggly or patchy, don’t assume that it is sick or in trouble. If everything else is normal–it’s active, alert, and feeding–it’s probably just molting.
If your bird feeder cam shows several birds molting, you can help these animals out:
- Provide food: Molting takes a lot of energy! Fill your feeder with high-protein foods like mealworms or sunflower seeds
- Provide water: A birdbath with clean, fresh water helps birds stay hydrated and cool when it’s warm
- Don’t stress them out: Give the birds space. Don’t get too close to them.
Molt season may not be pretty, but it’s an important part of most birds’ life cycles and a reminder that nature has all sorts of strategies for survival–even if they look strange to humans.