i heard some crazy bird noise, so i went out to investigate. i found two sparrows fighting in the tree between our house and the neighbors. one was a house sparrow and the other was a regular sparrow. the regular sparrow was making staccato clicking noises and the house sparrow was chirping hard. they were circling and puffing their feathers out. it was enjoyable to watch. a car's horn sounded, which immediately drew all their attention, and shortly after, the house sparrow flew away.