Social and ecological factors associated with innovation in urban sulphur-crested cockatoos (Cacatua galerita)

Abstract

Why some species thrive in urban environments while others do not is a central question in behavioral ecology. Behavioral innovations has been proposed as a key mechanism facilitating this adaptation. At the individual level, innovativeness varies with cognitive and behavioral traits. However, at the population level, innovation rates can also be influenced by social and ecological factors including group size, and environmental novelty and complexity. The role of these factors are still under-explored, especially at within-city scales. To disentangle factors influencing group-level variation in innovation rates, we presented roosts of wild sulphur-crested cockatoos Cacatua galerita, with extractive-foraging tasks that required innovative problem-solving. We installed three tasks of different levels of difficulty on trees at fifteen communal roost sites across an urban matrix. We matched these with direct measures of roost-size and connectivity, and with high-resolution remote-sensing mapping to estimate variation in urbanization and environmental heterogeneity. We found that approach time was significantly associated with urbanization, with individuals in more urban sites approaching tasks more quickly, suggesting reduced neophobia with urbanization or increased familiarity with human-derived objects. In contrast, time to innovate in our study was explained by task difficulty rather than environmental and social factors. While we detected no significant effects of group size, connectivity, and environmental heterogeneity, larger sample sizes may be needed to reveal more subtle influences on innovation. Together, these results suggest that urbanization gradients can shape behavioral responses to novelty independently from problem-solving abilities. Lay SummaryCities are challenging places for wildlife, but some species, like sulphur-crested cockatoos, adapt by finding new ways to feed and solve problems. We studied how urbanization and social factors vary with cockatoos ability to innovate when presented with extractive-foraging tasks. We found that birds in more urban areas approached the tasks more quickly, suggesting reduced neophobia or increased familiarity with novel objects. This work highlights behavioral differences across urbanization gradients in human-dominated environments.