They might think faster because the brain is smaller - a shorter distance for connections.
For example, learning to play a piano is training the spine, not the brain. Because the feedback loop with the spine is shorter.
It's the same with dancing. One is trained to not look at one's feet, because the feedback loop is too slow.
Looking at one's feet is also inefficient since you don't dance with your feet.
And playing a musical instrument like piano depends heavily on interactive processes throughout the brain and PNS
> For example, learning to play a piano is training the spine, not the brain. Because the feedback loop with the spine is shorter.
It may train the spine too but good luck trying to play the piano without a brain. More concretely, your eyes read the notes you like to play, your ears provide the feedback loop whether you are playing the right thing (and dynamics and interplay with other musicians in an ensemble), and you need things like planning ahead, sense of form, etc. Twiching fingers from some spine impulse is just part of playing the piano. (Besides, the latency between brain and finger muscels is insubstantial w.r.t. the time scales you need for general music playing, beyond certain nuances.)
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.