The social structure of these cliff swallow colonies have evolved a complex vocalisation system. Five vocalisations have been identified, which are used in both juveniles and adults for different reasons. These vocalisations are structurally similar across the age groups and can be described as: begging, alarm, recognition and squeak calls all with some variations. Juvenile cliff swallows are said to have established a unique call by the approximate age of 15 days, which allows the parents to identify their chick from others in the colony.