A study published in the Proceedings of the Royal Society B: Biological Sciences shows that song birds fed on a restricted diet in early life fail learn the songs that they would normally use to attract a mate.
The brains of song birds contain a nucleus called the higher vocal centre (HVC), which is required for the acquisition and production of song by males of songbird species. In male songbirds, the size of the HVC varies seasonally; just before the beginning of the mating season, the generation of new cells causes the HVC to increase in size, enabling the bird to produce a song in order to serenade potential mates. Once the mating season has ended, many of the HVC cells die, and the nucleus decreases in size.
Scott MacDougall-Shackleton and his colleagues, of the University of Western Ontario in Canada, reared 26 song sparrows (Melospiza melodia) from hatching; half of the birds were fed an unrestricted diet, and the other half were fed two-thirds of a normal diet.
Upon examination, the researchers noticed that the HVC failed to develop properly in the brains of sparrows given a restricted diet. As a result, those birds were unable to learn new songs to attract mates.
The findings beg a question: does diet have an effect on brain development in human babies?