I have 2 Sebs, 2 months old. April is coming along just fine but I notice that Bernie keeps chewing/pulling his flight feathers out. Maybe new feathers are itchy?
How many times will they grow back?
Is he pulling them out, or are they breaking off? If they are breaking off, I would think something missing from the diet (sulfur amino acids), poor amino acid metabolism, or fault bars causing them to break. Fault bars are usually caused by stress events while the feather is growing, and it can be as insignificant as a light being turned on while the bird is sleeping.