There are a number of reasons why your bird may be losing its feathers. This may happen when you bring a bird home first and if so keep him away from all other birds as he may have a illness and may spread it.
Birds also go through periods of losing feathers called molting. This is not a problem and is natural. However if you think it is sickness and not molting move him away from the other birds. Some birds suffer from an illness called French Molting, no one knows why this happens but it usually causes feathers in the tail to fall out. It will also mean the bird will have a shorter life span. Dipping the tail in disinfectant is known to help.
Feather plucking is also seen as a problem to do with a lack of minerals. Birds pluck feathers and chew on them to get minerals. Sometimes adding fruit tree branches helps this.
The bird may also have a cold, runny noses and red eyes are signs of this as are loose droppings. This can also be due to a change in diet. Add ViamanB12 to the birds drink to combat this. These should give you an answer to why the bird is losing its feathers.
This could be stress or just normal, depends on the amount of feathers its is losing. If it is a fair bit it could be stress and could be pulling them out its self. If you are very close to your bird when you leave the house he could be so stressed that your gone he could pluck them out himself.if only a small amount- when birds preen some feathers could naturally fall out.
Birds could be molting naturally and it is also a healthy things. Secondly it is a sign of stress. Your bird might be upset and stressed. Thirdly in parrots, they self mutilate which means they pluck their feathers by themselves.
My answer would be self-mutilation, as well. I once rescued a parrot that had no head, neck, or shoulder feathers. As soon as I got him into the right sized cage, and on a good diet, started covering him at night, and didn't stress him, they grew back. He'd been in a household full of male roommates who threw sunflower seeds and peanuts on the floor of the cage to feed him, he was in a very small cage, and it was hanging from a hook in the middle of the living room, where all the activity was going on. Plus , he was probably in a draft, and wasn't being covered at night. Feather plucking in the pattern you describe sounds like the bird is stressed.
It sounds like your budgerigar has a mite infestation. Please take it to an avian vet for a proper diagnosis.
Birds do naturally loose feathers when moulting but this does not create bald patches. Bald patches are an indicator for mites or feather pulling. A stressed, unhappy, or traumatised bird may self mutilate (pull out their feathers) both parrots and cockatoos are prone to do this more so than other species... But they will usually only do it as a reaction to a traumatic situation. If a bird is feather pulling, then it too will need to visit avian veterinarian to diagnose why and possibly treat it for any infections. Your local avian vet can advise you about how to care for your budgerigar so that you can enjoy the company of a happy, healthy friend for many years to come.
Check for mites,if their present...many treatments are available
Feather loss appearing around the eyes and moving through the face?
Bird molt sometimes as well as ducks, but if the feathers don't grow back in a few weeks, take it to the vet.
Because it's lonely it needs company.
Its just going through it yearly moult. Make sure you keep giving it plenty food to help it through takes a lot out the bird. I've lost birds in the past when going through their moult
Help me, my duck is pulling/losing big wing feathers and I don't know what to do. I think she is stressed because she started biting me . She is molting at the moment but these big wing feathers are unusual! Help me! I don't want to take her to a vet (too much trouble and costs heaps!)
Have you noticed anyone in the your neighborhood creating feathered woman's hats? I thought, I would asked to eliminate one possible answer, right out!
Because your bird is sick and has problems