Socializing, and engaging in complex behaviors, is associated with better memory and cognitive function.
40 days after being exposed to their new environments, both groups of birds were killed by an overdose of anaesthetic, and their brains removed for analysis. The brains were dissected, and the numbers of BrdU+ (that is, newborn) cells per cubic millimeter in two different regions of the brain was estimated. One of these regions, the nidopallium caudale (NC), is involved in the production of birdsong. The other, the hippocampal complex (HC), is involved in spatial memory, and is particularly large in those bird species that cache food.
However, one must always be on the lookout for a mad scientist with a syringe full of anesthetic!