This field guide is great for getting basic background information on all species in the study area. However because my 4th edition is dated 1993 its 20 years out of date with the research. A great deal of it hasn't changed, of course, but we've learned a lot more in that time frame. Additionally all the photos and drawings are black and white, and not very good for field identification.
If you're looking for something to use in the field, I'd choose a different book. If you're looking for background information on only the species in the study area, its very informative.