Killdeer (Charadrius vociferus) look like sandpipers who lost their way to the beach. These members of the plover family are commonly found in farm fields or park lawns. They lay their spotted eggs on the ground & protect them through deception.
If you walk near a nest, the adult killdeer will feign a broken wing and flap awkwardly along the ground, while crying loudly. It's a very eye-catching display, intended to draw predators away from the eggs. If you follow the bird, it will struggle at ground level, moving away from you at a slow pace, apparently easy prey.
This display continues until you (the threat) have followed it away from the nest. Then, the killdeer "miraculously" cures itself and flies away with strong wingstrokes.
I teach economics at Kalamazoo College. My wife is also an economist. We were on sabbatical in Europe for the 2014-15 academic year. (Salamanca, Spain, followed by Oxford, UK.) We were in Uruguay for the 2006-7 academic year.