Abstract:
Mixed-species flocks are a prominent form of social
organisation of foraging birds, particularly in the
tropics (Powell 1985). In general, the occurrence of
such flocks has been explained in terms of adaptations
to reduce predation and increase foraging efficiency
(reviewed in Morse 1977, Terborgh 1990). Flock
systems vary widely in the numbers of species and
individuals involved, with some of this variation
explained by factors related to predation, including the
openness of the vegetation and the density of avian
predators (Thiollay 1999). More studies from different
regions and habitats in the world are needed to further
document the diversity of flock systems and better
understand the applicability of the hypotheses that
explain flocking.
