The other night I was out in the meadow taking some sunset pictures — a beautifully serene setting. A light breeze, songbirds in the distance, no sign of humans other than myself, and swallows floating around above. As I squatted down to get a good angle, what sounded like some kind of fluttering pterodactyl scream came zooming down at me and scared me half to death. Turns out they weren't swallows, but nighthawks:
I'd never heard anything like it before.