Abstract
In animals, large variation for vocal individuality between and within call types exist, yet we know little on what level selection is taking place. Identifying the selection pressures causing this variation in individuality will provide insight into the evolutionary relationships between cognitive and behavioral processes and communication systems, particularly in group-living species where repeated interactions are common. Analyzing a species’ full, large vocal repertoire on individual signatures, its biological function, and the respective selection pressures is challenging. Here, we emphasize that comparing the acoustic individual distinctiveness between life-history stages and different subjects within a call type will allow the identification of selection pressures and enhance the understanding of variation in individuality and its potential strategic use by senders.