Midnight's Choice by Kate Thompson
This is the sequel to "Switchers" and was also very good.
This time Tess is alone, Kevin having been stuck in the form of a pheonix. She goes through a rough time with her parents and she misses Kevin terribly. One night Kevin is caught and put in a zoo. He will soon be sold to a private collector and Tess needs to save him. She soon finds out that she is not the only switcher in the city. She meets a boy named Martin, who has found some things out about thier powers... Tess needs Martin's help to rescue Kevin, but will he give it?
4 3/4 stars