Meyer’s are wonderful little birds, and congratulations for the good care you have provided that has helped your bird live to such an advanced age. At 28, she is most definitely a senior. When you say she lost all of her colored feathers, are you referring to the feathers on her chest? What about the shoulders? Does she have down feathers remaining or just bare skin? It sounds as if something made her pluck her feathers suddenly. This can happen, and in a case like this, it is a bit of a mystery. While you say nothing has changed, think about even the smallest change. Weather changes bring indoor changes, such as changing from AC to heat, or a fireplace. Has there been any outdoor activity that is unusual? Loud noises, parties, construction? Is she near a window? Is the cage covered at night? Could there be a new outdoor light at your house or a neighbor’s? A new dog in the neighborhood that barks? A feral cat loudly calling? When a bird plucks this many feathers all at once, especially at night, it is usually related to a scare of some sort. Given her age, you might want to take her to an Avian Vet to rule out an internal cause. I would watch her carefully for any other changes. Make sure she can’t see out of the windows or partially cover her cage at night if you don’t. Unfortunately there isn’t a clear or quick solution. You will need to observe her, make sure she is healthy by taking her for a Vet check, and see if this continues. If it was a scare of some sort, she may not do this again. If you want to send pictures, you can submit them to email@example.com and ask them to forward the pictures to me.
Thank you for asking Lafeber,