Corvids and Parrots, and Now Icterids, Are Some of the Brightest Birds That You'll Encounter

https://news.nationalgeographic.com/2018/03/year-of-the-bird-brains-intelligence-smarts/

Corvids Have Emotions and Sharp Minds

http://www.sciencealert.com/crows-ravens-corvids-best-birds-animal-intelligence

Who You Calling Stupid? Pigeons Can Discriminate Space and Time Concepts

https://www.ndtv.com/offbeat/pigeons-arent-bird-brained-can-understand-concepts-of-space-time-study-1783897