Social interactions and vocal communication in the Eurasian griffon vulture

A bioacoustic approach

The genus Gyps, which includes the vultures commonly known as griffons, is unique within the Accipitridae family due to its highly social behaviour and the formation of large colonies, where cooperation plays a key role in their survival. Traditionally, vocalisations such as croaking, hissing and screeching in these large raptors were considered to be almost exclusively associated with competition for food resources. Despite extensive research on Gyps vultures, vocal communication related to social interactions had remained poorly understood.

This bioacoustic study on the Eurasian griffon vulture (Gyps fulvus) aimed to investigate the structure, function and meaning of vocal emissions, identifying when and why different sound types are produced. The project sought to demonstrate that the complexity of vocal communication in birds is not limited to passerines, but may also reflect the evolutionary and social history of the species.

Based on the Social Intelligence Hypothesis, we predicted that the communication system of the Eurasian griffon vulture is more complex than previously assumed. A dedicated methodological protocol was developed to investigate vocal behaviour across key ecological contexts, including feeding sites and roosting and nesting cliffs.

The first phase of the study focused on:
(i) a quantitative and analytical description of the species’ vocal repertoire across different age classes (adults, sub-adults, juveniles and nestlings), using the Central Apennines population as a model;
(ii) the association of distinct vocalisation types with specific behavioural and ecological contexts.

The second phase will address mechanisms of individual recognition and interactions with other species sharing the same ecological niche.