The bird robots have a problem: their light battery only allows for them to fly two o three minutes, or so.
But maybe cars could beam them electricity wirelessly. (see http://en.wikipedia.org/wiki/Wireless_energy_transfer).
Still, I think birds would be better with the lights I envision, but I may be wrong. I don-t know that much of animals psychology, etc.
Indeed, most people, if not all, completly dislike this idea of mine.
So yeah, maybe bird robots is more cool