(Picture taken from Wikipedia. Link at bottom of the blog.)
Many birds nest on the ground and graveyards are a great place for them to nest. This is a Kildeer nest that was located in between the markers. The mother bird was doing the I'm hurt dance so I started immediately watching for the nest. If you are not familiar with Killdeers they have an interesting response when you get close to the nest. They will stick out one wing and act like it's broke and if you approach them the will run a little ways and do it again. This is how they draw predators away.