Scientists have long questioned whether there is any correlation between brain size and cognitive ability in various animal species. One theory often explored in this field is the cognitive buffer hypothesis, which explains bigger brain size by the adaptive benefits to respond quickly to sudden, rapid changes in the environment. A new study tests out this hypothesis among birds. Researchers studied bird brain size in both stable environments and variable environments, and to their surprise found that big brains are equally likely to evolve in both types of habitats. However, their findings also suggest that variable environments are more likely to be colonized by species that already have big brains, which might explain the origin of the key assumption in the cognitive buffer hypothesis as related to birds.


Trevor S. Fristoe, Andrew N. Iwaniuk & Carlos A. Botero

Corresponding author:

Trevor Fristoe, Washington University in St Louis, Missouri, US, Email:

Canadian author:

Andrew Iwaniuk, Department of Neurosciences/CCBN, Bird Brains Lab, University of Lethbridge, AB, Email:

Original paper published in Nature Ecology & Evolution on September 25, 2017.