a friend had two sulfer crested cockatoos and told me a story once.

He had two, a male and a female.

The male played industriously and was adept at doing all kinds of things, like untying zipties. (my friend added zipties to the cage as a toy). The female never touched any of them.

One day, my friend and his buddy were sitting there, and they mentioned this out loud. "She can't untie these things, I think she is just stupid compared to (the male)"

At which point, the female went over, untied the ziptie, spat it out and walked away. My friend and his buddy sat there open-mouthed.