An Eastern Kingbird sittting aside one of her 4 youngsters. Although they are called Eastern Kingbirds they are found throughout the U.S. If a hawk happens to fly near their nesting territory, the kingbird parents will drive it off with great vigor sometimes "riding" the back of the hawk in flight. A kingbird was actually observed to knock a Blue Jay out of a tree and cause it to hide under a bush to escape the attack.
