First, strangely, the owls had died. At the time it had seemed almost funny, the fat, fluffy white birds lying here and there, in yards and on streets; coming out no earlier than twilight as they had while alive the owls escaped notice. Medieval plagues had manifested themselves in a similar way, in the form of many dead rats. This plague, however, had descended from above. After the owls, of course, the other birds followed, but by then the mystery had been grasped and understood.

- Do Androids Dream of Electric Sheep? (1968)

One of the major themes in the story are animals; most species have been wiped out and people own artificial versions instead. Decker himself is motivated by a desire to own a "real" animal. Interesting that they mostly left this out of the film version (Blade Runner) and only vaguely mentioned it. In general, the book is very different, but discussion of animals takes up at least 1/4 of the narrative.