I cover the wings with newspaper dipped in raw flour and paper paste. There are great tips of how to make it here.
Once the wings are dry I cover the body with paper mache clay. I do this using plastic gloves, they help me spread the paste without it sticking to my hands. There is a great recipe here.
Once everything is completelly dry, I cover it with evenly with a layer of gesso, and once that is dry I colour the birds with acrylic paint. You can also put a layer of matte or glossy varnish to protect them.