What behavior might cause birds to tear up turf?

Birds tearing up turf is often associated with their behavior of feeding on grubs. Grubs, which are the larvae of various beetles, reside in the soil beneath the grass and are a significant food source for many birds. When birds search for these grubs, they will peck and dig into the turf, leading to visible damage in the lawn.

In contrast, behaviors like building nests in the grass or nesting on the ground do not typically result in tearing up the turf. While these activities can disturb the surface slightly, they are not driven by a feeding instinct that leads to digging. Feeding on seeds, while common for some birds, would not cause the same level of disruption to the grass as the search for grubs does. Therefore, the most compelling explanation for birds tearing up turf is their search for grubs beneath the surface.