Birds: Nature's Magnificent Flying Machines is a book by Caroline Arnold and illustrated by Patricia Wynne for, I'd say, Pre-Elementary School kids and first/second grade. This is a good book to read to a pre-literate kid. Then put it away for later when the first grade academic report on birds is due ... it will be an excellent reference.
This is a well done and highly recommended book.
Birds... is highly specialized. It deals with only one topic: Bird flight. I like that. Who needs just another book on birds. Demonstrating to the little ones that there are questions that can be asked about nature, and interesting explanations, and even some experiments, one can do is a clear step above the pretty picture and the cute story.
The illustrations are excellent. You may have seen Wynne's illustrations previously in the African Savanna book (which, as an older volume is a great bargain at less than 10 bucks). Both author and illustrator of Birds... have been producing excellent kids books for a long time.
At the very least, this book has value because it introduces kids to the fact that birds don't just sit there looking pretty and making noise, and they don't just fly from place. They have more complex behaviors that vary across species and across context.
By the way, the author, Caroline Arnold, is a home-girl from Minneapolis! As you can tell because of the excellence of her work.