The formation and significance of social network structure in monk parakeets (Myiopsitta monachus)

Parrots represent an important taxon in which questions about the evolution of complex sociality can be studied. However, we currently have little quantitative knowledge about how parrot groups are structured. I provide some of the first information on parrot social structure in one species, the monk parakeet (Myiopsitta monachus), using social network analysis. First, I developed an analytical framework to investigate the patterns of formation and stabilization of social networks in captive groups. I found that monk parakeet social structure can form and stabilize quickly, but the patterns and rate differed by the type of relationships considered. Second, I tested the significance of social associations and relationships and used auditory playback experiments to determine how assessments of social relations corresponded to the parakeets' perception of their own social ties. I found that methods for assigning a relationship strength or category could result in significantly different social networks. I also found that social networks did not predict either response patterns or the perception that individuals had of their own ties. Third, I tested several of the widespread assumptions about parrot social structure with captive and wild monk parakeets and compared these results to patterns of social structure found in other species. I found support that the fundamental social unit is the dyad and that monk parakeets have fission-fusion dynamics, some evidence that dominance hierarchies may be important in structuring monk parakeet social groups, and little evidence that monk parakeets cooperate by sharing foraging information. I also found that aspects of monk parakeet dominance hierarchies exhibit striking differences from other species that have been studied. Finally, in Chapter 5, I evaluated three methods used to describe and predict human social interactions (power, influence, and social capital), adapted and formalized them for use in animal behavior, and described the potential utility of metrics that can be compared across groups, species, and taxa. My project provides some of the most detailed information to date on parrot social structure and methods within which questions about the dynamics of social networks can be addressed as well as methods to facilitate comparative analyses across species to better understand the evolution of complex sociality.