The book isn't terrible! It's a fairly good place to start for beginners, however if you are studying for an animal related science degree, it's probably better to start with the Dictionary of Zoology and other similar books.
The one thing that does annoy me; at the back of the book it states 'Includes an index of common and Latin animal names' - just to clarify, it should be scientific names, not latin, as many animal names are in various different languages, for example, a white flesh eating slug ('ghost slug')recently discovered in wales, has a welsh name - elenochlamys ysbryda (ysbryda meaning ghost). Make of it what you will, but things like that from someone who should know better, leaves a trail of doubt.