The structure of mixed-species bird flocks, and their response to anthropogenic disturbance, with special reference to East Asia

Eben Goodale,Xiaohu Liu,Scott K Robinson,Mitch Walters,Ping Ding,Xingfeng Si,Ari Martínez

doi:10.1186/s40657-015-0023-0

Abstract

Mixed-species flocks of birds are distributed world-wide and can be especially dominant in temperate forests during the non-breeding season and in tropical rainforests year-round. We review from a community ecology perspective what is known about the structure and organization of flocks, emphasizing that flocking species tend to be those particularly vulnerable to predation, and flocks tend to be led by species that are able to act as sources of information about predators for other species. Studies on how flocks respond to fragmentation and land-use intensification continue to accumulate, but the question of whether the flock phenomenon makes species more vulnerable to anthropogenic change remains unclear. We review the literature on flocks in East Asia and demonstrate there is a good foundation of knowledge on which to build. We then outline potentially fruitful future directions, focusing on studies that can investigate how dependent species are on each other in flocks, and how such interdependencies might affect avian habitat selection in the different types of human-modified environments of this region.

Highlights

Mixed-species flocking of birds is a well-studied, broadly distributed biological phenomenon
Mixed-species flocks qualify as “community modules” in which biotic interactions such as competition, mutualisms, and predation are highly concentrated in space and time and, are especially amenable to scientific investigation, and naturally interesting to community ecologists
One approach derived from community ecology is to analyze flocks as a subset of the avifauna, and to try to understand and predict which species should be in flocks and what roles different species play (Goodale et al 2010)

Summary

Introduction

Mixed-species flocking of birds (hereafter referred to as “flocking”) is a well-studied, broadly distributed biological phenomenon. Mixed-species flocks must be distinguished from assemblages that gather at a localized resource in that they are always moving (Powell 1985), and most species involved in forest flocks. Given this broad distribution and dominance of mixed-species flocks in some areas, any study of bird community organization must incorporate them in some way. A second and Goodale et al Avian Research (2015) 6:14

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Conclusion