All About Cages . Perches - Birds spend a lot of time on their perches. They need perches of varying diameters to prevent foot problems such as arthritis and atrophy. Avoid perches made from dowels, which are uniform and don't exercise feet. Never use sandpaper perches which harm the skin on a bird's foot.
Tree branches are very good for the feet and also help satisfy the chewing urge.
A cement perch can help keep nails trimmed. Put a wooden perch high in the cage, which birds prefer. Use multiple perches, but leave room for birds to move about in the cage. All About Perches . Feathers - Feathers grow back.