Big Brains, Enhanced Cognition, and Response of Birds to Novel Environments

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 102; no. 15; pp. 5460 - 5465
• Main Authors: Sol, Daniel, Duncan, Richard P., Blackburn, Tim M., Cassey, Phillip, Lefebvre, Louis, Orians, Gordon H.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 12-04-2005; National Acad Sciences
• Subjects: Animal cognition; Animals; Average linear density; Aves; Biological Sciences; Birds; Birds - anatomy & histology; Birds - classification; Birds - physiology; Body Weight; Brain - anatomy & histology; Brain - physiology; Brain research; Cognition; Cognition - physiology; Empirical evidence; Environment; Estimated taxes; Feeding Behavior - physiology; Geographic regions; Models, Biological; Organ Size - physiology; Size; Technological innovation; Thinking skills
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.0408145102

The widely held hypothesis that enlarged brains have evolved as an adaptation to cope with novel or altered environmental conditions lacks firm empirical support. Here, we test this hypothesis for a major animal group (birds) by examining whether large-brained species show higher survival than small-brained species when introduced to nonnative locations. Using a global database documenting the outcome of >600 introduction events, we confirm that avian species with larger brains, relative to their body mass, tend to be more successful at establishing themselves in novel environments. Moreover, we provide evidence that larger brains help birds respond to novel conditions by enhancing their innovation propensity rather than indirectly through noncognitive mechanisms. These findings provide strong evidence for the hypothesis that enlarged brains function, and hence may have evolved, to deal with changes in the environment.