I found a pigeon sitting on the ground alone it let me pick it up and it had a band on each foot. One is just a plain white band. The other is a bigger white band with numbers on it. Both feet are swollen and limp she cant walk or stand up. She uses her wings like crutches. It seems as if the bands are two small for her. She is also missing a big patch of feathers on her belly. I got her to drink some water by dipping her beak in it but she hasn't eaten yet. She seems very tired and is sleeping now. What is wrong with her legs?