Turns out that a certain silvery/white colored car parked right along the birds fly-way. The sun glinted off the car's surface. The birds -- esp. the geese -- got startled en mass and bombs away.
I once had a blue-gray car that was a special target for birds. I couldn't believe it when, one day, I walked into the parking lot where approximately 7,000 cars were parked and only MY CAR was covered with bird poop. It was really strange.