Abstract:
The birds of tropical rainforests present the most complex array of ecological interactions. In the Amazon, mixed-species flocks (MSF) have captured the attention of various investigators. Various studies explain that the tendency of birds to form polyspecific groups reduces predatory pressure and increases foraging efficiency. This chapter considers three assumptions suggested by English to classify the flocks: individuals moving at the center of the flock, moving with the flock for more than 30 minutes, and individuals that move with the flock but do not meet the first two assumptions. Canopy flocks presented a less aggressive behavior than understory flocks, as frugivorous birds do not aggressively defend their territories like insectivorous birds do. Habitat type presented a positive correlation with the number of participants in the flocks, suggesting that there is a higher number of species and individuals participating in flocks at zones of terra firme forests, contrary to the situation in swamps.