I believe that there are fundamental architectural differences. It's possibly related to birds doing continuous breathing rather than tidal breathing like mammals, so the limit of oxygen availability is higher.

The flying lifestyle creates size constraints, and nerve conduciton distances will be shorter and that will make some sort of difference.

But dusting off some very rusty student memories, we're not really working in real time - some latencies bottom out a 5ms, but 30-100ms is more common - if I am recalling correctly.