Let’s be fair; this book is not a field guide in the standard parlance. It’s a bit too big to carry conveniently in the field, and it is not going to be much use as an identification tool for anyone but beginners – it goes for breadth rather than depth, covering wildflowers AND trees AND insects AND birds AND mammals AND herps, all very basically, and doesn’t even illustrate both plumages of the sexually dimorphic birds that it covers.
What Field Guide to the Natural World of New York City actually is is an excellent browsing book. It has beautiful watercolor illustrations and a wealth of interesting tidbits about the species it covers; I particularly appreciated that each entry includes an etymology of the species’ Latin name and, where it’s not obvious, the common name as well. It also includes detailed instructions for getting to various key nature-watching sites around the city by car and public transit.
This probably doesn’t need to be on the shelf of every hard-core birdwatcher, but it would make a nice gift for a friend who is interested in nature in a general sort of way, the one who is always vaguely describing something they saw and then asking you what it was.