Sparrows are as complicated as they are common. This is an essential guide to identifying 76 kinds, along with a fascinating history of human interactions with them. What, exactly, is a sparrow? All birders (and many non-birders) have essentially the same mental image of a pelican, a duck, or a flamingo, and a guide dedicated to waxwings or kingfishers would need nothing more than a sketch and a single sentence to satisfactorily...