Innocent. Invader. Lover. Thief. Sparrows are everywhere and wear many guises. Able to live in the Arctic and the desert, from Beijing to San Francisco, the house sparrow is the most ubiquitous wild bird in the world. They are the subject of elegies by Catullus and John Skelton and listed as "pretty things" in Sei Shonagon's Pillow Book--but they're also urban vermin with shocking manners that were so reviled that Mao placed them on the...