Pigeons have been trained to discriminate between different styles of art [1], which suggests complex, adaptable, visual processing and skill retention. So they

Pigeons have been trained to discriminate between different styles of art [1], which suggests complex, adaptable, visual processing and skill retention. So they may not be a great example of a bird that can only exhibit simple behaviours. [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1334394/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1334394/