When is a bird not a bird? When an author turns it into something else. As a child, I was envious of birds—they got to fly and I didn’t (although not for lack of trying. However, the less said about that, the better). Later on, during my Teenage Romantic Period, I idealized them as emblems of The Natural World, beautiful and perfect, training Wordsworth’s “cloud of glory.” Later still, I discover that what birds trail are lice, vermin, and some very nasty diseases.
Source: Five Books With Ambitious Birds