Science

Intelligence might be a common evolutionary outcome, considering birds developed high intelligence but took a different path to mammals.

Pigeons, with appropriate training, can discriminate between Picasso and Monet's masterpieces. Ravens can recognize themselves in a mirror. On a Japanese university campus, crows have been known to leave walnuts on a crosswalk and let passing automobiles crack them. Many bird species are very intelligent. However, the "bird brain" frequently receives little respect.

Birds' brains are far more akin to our complicated human organs than previously assumed. For many years, it was thought that the avian brain had restricted function due to the lack of a neocortex. In mammals, the neocortex is the massive, evolutionary recent outer layer of the brain that enables complex cognition and creativity. Yet birds' brain structure at a microscopic level is similar to the neocortex in places, despite its differing shape. While birds and reptiles may not have a neocortex, they do have some of the same neurons. They're just in different places. It turns out that at the cellular level, their brain are structured similarly to the mammalian cortex and doing similar tasks, which explains why many birds exhibit advanced behaviors and talents.

On an evolutionary time scale, high Intelligence may not be particularly unique or unusual. Complex brains and cognitive processes may have developed separately multiple times, as have the circuits and neurons that control them.

See also https://www.scientificamerican.com/article/bird-brains-are-far-more-humanlike-than-once-thought/