The books are educational because they provide information little ones wouldn't know about the life of a bird. However they're all told in rhyme, which is often forced. The first one, which uses the same rhyme scheme for every single sentence was annoying to me, but very young children probably won't mind hearing the constant repetition of the same sound as the books are read aloud to them. In fact they might like it.
The illustrations by Kristin Metcalf are beautiful and manage to be scientifically accurate and charming at the same time.