More interesting was a bird we passed, which was sitting on a power line and chirping a constantly mutating song.
Instead of sticking to one main sound, the bird seemed to be listening to other birds in the neighborhood and changing its song accordingly.
Unfortunately, the bird's a bit high, so it's difficult to see the bird's markings. It appeared to be mainly gray, with a long, dramatic tail and a thin, dark beak.
I'd like to imagine the bird was composing a new song just for us. Perhaps it was aware of the baby sitting in the stroller 20 feet below, admiring the "birdie" his mama had just pointed out. "Oh, a small human," it said, "and this one appears to be a music lover. Maybe I'll show off." So he composed a special tune just for us.
But in actuality, it's either an animal mimic or simply a bird with a sophisticated musical repertoire. Can anyone tell me?