It amazes me that Killdeers have not become extinct. They're actually the most widespread plover in America. They're extremely common in fields, both man-made and natural. They lay their eggs out in the open on little stick nests. Unfortunately, they don't really understand how the game of soccer works (or baseball, or football), so their nests sometimes get trampled by unsuspecting sportsmen. They also try to draw predators away from their nests by doing a "broken wing dance" and making a sad, sad little noise.
Like I said, can't figure out why they exist. I took this picture in Corpus Christi, Texas in the parking lot of a La Quinta hotel on October 20, 2012.