Wow, that's pretty cool, I didn't know any of that. From the wikipedia link, it seems this should still be consistent with lotusleaf's suggestion: the avian se

Wow, that's pretty cool, I didn't know any of that. From the wikipedia link, it seems this should still be consistent with lotusleaf's suggestion: the avian sex chromosomes are thought to be related to the autosomal chromosome 9 in mammals - so any variability in intelligence which was determined by X-chromosomal genes would not necessarily be as apparent in those ZW-carrying animals.