should i put sand paper around my macaws perch to file her nails?

Sandpaper perch covers are not recommended. They are too rough and can cause wear on pads and open sores on the bottom of your bird's feet.

Stores likes Petsmart and Petco sell perches that are designed to help keep your birds nails trimmed. You will still have to occasionally have them trimmed or you can do it yourself. Follow this website for a "how-to" guide for trimming the toenails yourself:

http://thetrueparrot.homestead.com/howtonails.html
http://www.krcexoticbirds.com/main/faq.html#g