A sound like a cooing dove when headlights are on??

For the past few weeks, I have been hearing a cooing or hooting sound of a mourning dove or an owl - swooping up, then down, then up, etc. - when my headlights are on. At first I heard it only when I had turned the car off and the lights were still on. If I manually turned off the switch for the headlights, the sound stopped.

Now I also hear it when the car is running and the lights are on. If the lights are turned off, I do not hear it.

And no, there are no trapped birds in there.