Black-capped chickadees (and probably some other songbirds) have an amazing ability to increase the effective size of their brains during the time of year where they need to store more information. Specifically, in preparation for winter, the chickadee will hide seeds and other food in hundreds of locations. In order to remember all of this data, the bird actually grows more neurons in its hippocampus (the part of the brain where one remembers where one stored seeds) each autumn to the point where the hippocampus increases 30% in volume. When springtime comes and the bird no longer needs to recall where all the food stashes were, it can concentrate on sex, and its hippocampus shrinks back to its original size.
It used to be dogma that all higher animals could not make new nerve cells once they had achieved adulthood and that humans could not do so after about the age of two. With respect to humans, this is still fairly accurate, although a human does have a limited ability to renew cells in his or her hippocampus (but not by 30%!) throughout life.
While the idea of having a very flexible hippocampus which can expand to absorb a lot of information is appealing, the more permanent nature of the human brain serves a function. When the chickadee's hippocampus shrinks, a lot of those memories are flushed away. A human, however, with his or her original neurons and pathways, can remember events from fifty years ago (although, as I can attest, not where he put his car keys last night). On the other hand, knowing more about how the chickadee plies its mind-expansion techniques may help scientists treat Alzheimer's and other forms of dementia.
For more info on chickadee intellectualism, click here.
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