A BIG brain is a sign of a healthy immune system, at least as far as male birds are concerned.
Anders Møller at Pierre and Marie Curie University in Paris, France, and colleagues examined data from 127 bird species. They found that in species with larger brains for their body size, such as yellowhammers and barn swallows, the males also tended to have a larger spleen and bursa of Fabricius – two organs central to the immune system. The pattern did not hold for organs like the heart and liver not involved the immune system, or for females (Journal of…
