Crows (and certain other bird species) have a peculiar forebrain (different in structure but similar in function/evolution to the neocortex in mammals) with neuron counts rivalling primates. So the nr of neurons still matters, but likely not across the entire brain.

my understanding is that extream migrators actualy consume (use as energy) parts of there own brains durring there epic flights, and other species do something similar in the winter and regrow parts of there brains every spring.

It is true that they can shrink some organs to reduce weight and store extra fat, but the brain is not one of them. Would be pretty bad, because brain cells can't regrow like e.g. a liver can.

Yep. And my point is that too many people seem to judge intellect by brain size or mass. Something like "Neanderthals must've been smarter than Sapiens, because their brains were larger". Or "chimpanzees are smarter than gorillas because gorillas have very small brains", which is all true, except for the word "because" (gorillas are leaf-eaters, so they did not have evolutionary pressure to be smarter, no need in more complex hierarchies, and maybe less proteins for the brain).

Obviously an M1 chip is “smarter” in terms of raw accuracy for eg matrix computations than any equivalent wetware despite being much? smaller. Performance per watt at least at that task has to be an ocean of a difference.