alt Hacker NewsCrows (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.