When you get close to their nest Killdeer will start doing a tail display or the “Broken Wing” display. This is to get potential threats away from their nest. When I see this type of display I usually stop and try to locate the nest, which can be very difficult as they have eggs with spots. These spots blend in so well with the ground, making them virtually invisible. I do this not to antagonize the bird but to locate the eggs so I don’t accidentally step on the eggs when I am trying to back off or go around the parent.
Taken in Ottawa, Ontario, Canada