Aggressive interactions between cavity nesting birds in SE QLD Australia

1. Context: A mechanistic understanding of the drivers of competition between species at a community level can improve invasive species management by helping identify where and when impacts are likely to be greatest. Invasive cavity-breeding birds provide a way to test shared traits and resource requirements are related to intensity of competition. Australia is home to one of the richest cavity-nesting communities globally with over 100 native and introduced bird species requiring hollows: but the impact of invasive species on most native communities is not well understood.  2. Methods: We examined aggressive interactions between birds in large hollow-bearing trees. To explore the drivers of aggression, we explored whether more similarly sized birds interacted more frequently, whether larger species won aggressive interactions more often, and whether cavity-breeding species with similar preferences for nesting sites (breeding niche space) interacted more frequently. 3. Results: We r...