Relative levels of food aggression displayed by Common Mynas when foraging with other bird species in suburbia

Abstract

Invasive species present economic and ecological challenges worldwide. In many cases we are not aware of the full effect they have on the environment, the extent of any damage, or the factors contributing to their success. In this study we examined the foraging aggression of wild Common Mynas (Sturnus tristis) as a potential explanation for their invasive success, and quantified the effect of this behaviour on other birds. Common Mynas did not display significantly more aggression than other species, and displayed significantly less aggression than native Australian Magpies (Cracticus tibicen). Furthermore, the presence of Common Mynas at a feeding resource had no greater effect on the abundance of heterospecific individuals than the presence of any other species. Presence of each species was negatively correlated with the presence of other species, that is all species were less likely to approach the feeding station if any other species was present there. Common Mynas also did not displace other birds at feeding sites any more frequently than three of the other four species, and less frequently than two other native species. Overall, the findings suggest that Common Mynas do not display more food-related aggression than other species in suburban habitats, suggesting that competitive aggression over food is not likely to be one of the behavioural traits leading to the success of Common Mynas in suburban habitats.