Habitat alteration modifies the structure and function of mixed species flocks in an Andean landscape

Understanding the responses of species interactions to land-use change is a key challenge in ecology and conservation. In the tropical Andes, a large proportion of birds interact with other bird species and create networks of mixed species flocks; however, the widespread effects of land-use change in the region raise concerns about the alteration of these interactions. Here we explored how structural (i.e., species richness and size) and functional (i.e., network connectivity indices) parameters of mixed flocks change along a gradient from open vegetation to native forest habitats. This study was conducted in the southern Andes of Ecuador, where we sampled mixed species flocks in 12 areas for five consecutive months, and applied network analysis tools to characterize structural parameters (observed richness, flock size, flock encounter rate, composition) and functional parameters (degree, weighted degree, cluster, and skewness) of flocks. We found that the network indices, degree and we...