Moulting tends to make finches restless and unsettled. It is probably uncomfortable for them. During the moulting season a bird’s behavior will also change, canaries for example won’t be able to stop singing.
During this season, diet is truly key. Moulting birds need much more protein than usual. One of the best ways to provide this is with egg food (see Egg Food in the Finch Food section of this guide). Some species will enjoy small bits of cooked meat. Fatty seeds such as flax, hemp and millet also help keep the new feathers in good condition as they grow. Hemp in particular acts as a sort of super-food, providing the perfect balance of omega 3 and 6 fatty acids, lots of minerals and plenty of protein.

A moulting Canary will stop singing
During the moult, birds will also be more susceptible to the cold. They will also need more rest than usual, up to 12 hours which means you will need to use a cage cover to simulate a long, comfy night.
Moulting birds also carry out more preening than usual. Each new “pin” feather has a sheath on its tip, and the finch will need to remove this to allow the feather to properly grow.
When Do Canaries Moult?
Canaries moult once a year, usually during the summer time. This entire process can take between six to twelve weeks. If your bird is moulting for longer than this, or is dropping feathers all year or develops bald patches, there are some underlying environmental/health issues you need to take care of.
Zebra Finch Moulting
Zebra Finches do not have an annual moult. This is also the case for a lot of other pet finch species with a few exceptions such as the Gouldian Finch. This doesn’t mean that they don't replace their feathers, they just do it gradually all year round.
This being said, these finches can still lose more feathers at one time, this is usually a sign of illness or a lack of protein in their diets.
Gouldian Finch Moulting
As mentioned above, Gouldians are one of the few species of pet finch that have an annual moulting cycle. Moulting takes place soon after the mating season and can prove to be stressful for the birds. The loss of feathers can happen all at once, resulting in bald patches. In most finches this would be a sign of some underlying problem, but for this species it is normal.

Gouldian finches have a particularly heavy moult
Again, diet is essential during this time. Plenty of protein and egg food is the ideal source. Gouldians should be kept in a warm environment no cooler than 75F.
Barbara, 15 September 2020
What r mites and how do u treat a canary and his cage?