Illustrations make very ineffective use of color, adding virtually nothing to black-and-white drawings (a large single shade of green for grass). A number of the figures (both human and animal) have those damn cartoon dot eyes. A qualified nature illustrator should have been hired.
Fantastic detail about birds and their feathers -- kinds of, when they get them, how used, how lost. Some introductory material on other animals who shed hair, skin or shells.