How smart are crows? How impressive is it that they understand water displacement?


I recently saw a video of a [crow using water displacement to retrieve food]( In several experiments, the crow was able to retrieve the food more efficiently by putting rocks into the narrower tube out of two available. It also chose solid weights instead of hollow ones, and discovered which of two tubes affected water levels very quickly. My question is, how impressive is this? What other animals would be intelligent enough to do this? At about what age could a human child figure this out?

In: Biology

Crows are considered to be just about the smartest animals on the planet, aside from humans, thanks to their ability to use creative problem solving, risk-reward analysis, simple tools, and even adapt to new situations and utilize new tools in an **extremely** rapid manner. Heck, they even use traffic to crack hard nuts.

Crows pack in more neurons, pound for pound, than any mammal including humans, and it’s generally believed that crows have about the same IQ as the average seven-year-old child.