What is moulting?
Every year canaries will go through the moult (also spelled molt) and will replace all of their feathers. They gradually lose their feathers and don't lose them all at once. If your bird suddenly become bald in places you may have mites (see disease link above). Usually the first year after a canary is born he won't replace all of his feathers, but in the second year even the tail feathers are replaced. My birds are at the end of the molt here in December. Molting is actually triggered by a change in lighting duration. After the breeding season you should gradually lower the duration of lighting. In all cases the canary lights should be on a timer to allow complete control over light duration. During breeding season give about 14 hours of light a day. To induce the moult, you should lower the duration of the light about 15-30 minutes a week until you are down to 8-10 hours a day. Birds going through the moult look kind of rough as they replace their feathers. During the moult the males usually sing less. This year I had 35 canaries and during the moult I was wondering if I had any at all since they all stopped singing at once!

What do to during the moult
The moult can be a stressful time for your birds and they should be given plenty of space, a lot of extra protein in their diet for feather growth and separate quarters if there is fighting. Extra veggies and egg food should be given to strengthen the birds. Don't forget to offer the birds a bath. To give a bath simply put luke warm water in a shallow dish or pan and the bird will do the rest! Make sure you take the bath out after about 30 minutes to keep the birds from drinking dirty water. Give your birds extra attention when they go through the moult and they will look better the rest of the year!