Towards_Keeperhood comments on Could orcas be (trained to be) smarter than humans? 

[Towards_Keeperhood]

Do we have a sense for how much of the orca brain is specialized for sonar?

I don’t know.

But evolution slides functions around on the cortical surface, and (Claude tells me) association areas like the prefrontal cortex are particularly prone to this.

It’s particularly bad for cetaceans. Their functional mapping looks completely different.