Have you ever been to a friend’s house and noticed that their dog’s or cat’s fur seems to be on everything? That’s because their pet is shedding. Like dogs and cats, birds go through a similar process known as moulting. When their feathers are damaged or get too old, the feathers are pushed out and replaced with brand new ones. Unlike dogs and cats, which shed their hair continuously (like all mammals), birds moult their feathers only once or twice each year depending on the species.
The timing and process of moulting often differs depending on the bird species; in fact, when moulting occurs it can even be different for individuals of the same bird species. Factors like time of year, location, mating, weather conditions and feather damage all play a role in when and how often a bird will moult.
One Complete Moult a Year
Many birds will go through one complete moult, where all their feathers are replaced once a year. These are birds like owls, swallows, jays, hawks and thrushes, just to name a few.
One Complete and Partial Moult a Year
Some birds, like warblers and tanagers, go through one complete moult but will also lose some of their feathers before getting ready to breed (call a partial moult). After this partial moult, the males will have bright and colourful feathers to attract females.
More Than One Complete Moult a Year
A few birds, like marsh wrens and bobolinks live in areas where their feathers get damaged more often than other birds so they will go through more than one complete moult in a year.
Moulting is a very intense process and can be very taxing on birds. It takes a lot to of energy (and food) to grow new feathers! During this time, the birds will add more protein, calcium and iron to their diet. They also move around less because it is difficult for a bird to fly very much when it is growing new feathers. Even though moulting is tough for birds, growing a new set of feathers is really important. After all, feathers are vital for regulating body temperature, protection and camouflage, attracting a mate and, of course, flying!