A classification scheme for mixed-species bird flocks

The literature on mixed-species flocks references a wide variety of bird associations. These studies, however, have used an array of unstructured characteristics to describe flocks, ranging from the temporal occurrence of flocking to the identity and behavioural features of constituent members, with little consensus on which key traits define and characterise a mixed-species flock. Moreover, although most studies report species-specific roles, there is no clear consensus about what these roles signify nor how to define them. This lack of consistency limits our ability to compare flocks from different habitats, regions, and species pools. To unify this sizable body of literature, we reviewed and synthesised 537 studies on mixed-species flocks. We propose 13 categories to classify mixed-species flocks using behavioural and physical traits at the flock and participant level, as well as the habitat where the flock occurs. Lastly, we discuss the historical terminology for different species roles and propose definitions to clarify and distinguish among nuclear, leader, sentinel, and flock-following species. We envision that these guidelines will provide a universal language for mixed-species flock research, paving the way for future comparisons and new insight between different regions and systems.

Fil: Mangini, Gabriela Giselle. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; Argentina

Fil: Rutt, Cameron L.. No especifíca;

Fil: Sridhar, Hari. No especifíca;

Fil: Buitron, Galo. Universidad Estatal Amazónica; Ecuador

Fil: Muñoz, Jenny. University of British Columbia; Canadá

Fil: Robinson, Scott. University of Florida; Estados Unidos

Fil: Montaño Centellas, Flavia. State University of Louisiana; Estados Unidos

Fil: Zarco, Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina

Fil: Fanjul, Maria Elisa. Fundacion Miguel Lillo. Direccion de Zoologia. Instituto de Vertebrados; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Fil: Fernández Arellano, Gilberto. Universidade Federal Do Mato Grosso (ufmt);

Fil: Xing, Shuang. Sun Yat-sen University; China

Fil: Camerlenghi, Ettore. Monash University; Australia