Mixed-species flocks are common in the winter, when joining a group offers better resource scouting and improved predator protection. In natural settings, resource partitioning allows birds in mixed flocks to forage in the same location without head-to-head food fights. Birds have evolved different foraging niches and strategies such as finding foods on different parts of a tree or at different heights, and over time they’ve evolved differentiated beaks for food specialization. For example, woodpecker beaks allow tree probing while heron beaks allow fish spearing.
Some species have evolved so they can bend just the tip of the beak, called rhynchokinesis, to access food. Shorebirds are known to use it to find, manipulate and consume buried prey. Hummingbirds use this ability to catch insects in mid-air, and research has been conducted on how they use it for nectar feeding.