How do young birds compete for food from their parents?

Young birds compete for food from their parents through several distinct behaviors designed to signal their needs and secure resources. Within a nest, chicks often engage in vigorous begging, which may include vocalizing loudly or displaying colorful gapes to attract parental attention.1

The likelihood of being fed is often determined by a chick's position relative to the nest cavity entrance or the intensity of its begging behavior. For example, young pigeons (squabs) compete by pushing against the parent’s breast while emitting a hunger note and inserting their bills into the corners of the parent's mouth to receive food via regurgitation.12

When food resources are scarce, competition can become more intense. In some species, such as great egrets, this competition may escalate to direct interference, including siblicide, where the first-hatched chick kills its younger siblings to ensure its own access to limited food. These signaling and competitive behaviors are evolutionarily favored because they help parents identify and prioritize feeding the most vigorous offspring, thereby increasing the likelihood that their investment results in surviving young.1