Ravens are Smart Answered
Check out this article for a really neat description of how and why ravens are smart. Basically, it's a great trait for a scavenger to evolve- they need intelligence and what amounts to a rather sneaky form of empathy to snitch lots of food from predators and hide it from their fellow ravens. Good stuff.
Ravens can toboggan, ride other animals and spy on their enemies. Their life as cadgers stealing prey from wolves, eagles and bears has made them outstandingly intelligent.