Did They Have Birds in the Fourth Century?

"How could you write about anything without wondering if it was true? I mean, you'd be describing a bird in a garden and suddenly there would be that awful question in your mind, did they have birds in the fourth century?" (Christopher Isherwood to Gore Vidal, Harpers, 1965)

One of the things my mother never understood about my career (or that she claimed not to understand; I wouldn't put it past her to have been yanking my chain) was why I, a writer of fantasy, bothered to do research. "It's ...