My anecdotal experience: I didn't care for the first book, then my kid was doing a school report on a Hawaiian bird and asked if I can use that bird on a cover.

My anecdotal experience: I didn't care for the first book, then my kid was doing a school report on a Hawaiian bird and asked if I can use that bird on a cover. I asked O'Reilly and they said yes, the animal wasn't taken. I guess chances are higher when the animal is more obscure.