Or so it seems from one study:
How do the corvids stack up against us? “Crows and ravens performed comparably to primates and children tested in [similar] tasks,” Hillemann said. But one difference between the avian brain and the primate brain may be the way that they consider quality versus quantity. Birds usually aren’t willing to wait in order to increase the amount of food, only to optimize the quality of their reward. “This may be unique to birds,” she adds, “because carrying a large amount of food can be disadvantageous in flight.” On the other hand, a human child can fit two marshmallows in his mouth just as easily as one. While more research is needed, this lends support to the notion that this sort of impulse control is a case of convergent evolution, having evolved independently in the avian lineage and in our primate lineage.
I found the entire post of interest.