I found this book interesting, but confusing. First, while the paintings are gorgeous, the animals are really easy to find. It's a little hard to grasp the concept of camouflage when they're so easily discovered. I found them all right away and I am awful at I Spy kinds of things, so that just shows you...Now, I do have families who like easy I Spy books, especially for their younger children, so that could be a good audience for this, but the descriptive pages seem more advanced. Even the habitat labels are odd, ranging from "deciduous forest" to "snow". The pictures also want you to count every single animal which is easy when they're all different but not so easy when there are multiples of one animal, like the 44 fairy basslets on the coral reef spread (pictured on the front cover).
Verdict: Easy I Spy books are a popular genre in my library and the paintings are bright and attractive, so despite some of the contradictions in the book I would recommend it. However, I wouldn't necessarily make it your first choice.