Attractive Birds More Immune to Bird Flu

Scientists at Sweden’s Uppsala University say the more attractive birds are, the more they are immune to avian flu.

Evolutionary biologists have long attempted to explain why individuals of a species differ in appearance and why the choice of a mate is influenced by behavior and appearances that cannot reasonably be thought to have any usefulness.

Therefore, they have begun to look more at the genetics behind what are called secondary sexual characters, such as the tail of a peacock.

One theory posits the ornaments are clearest on individuals that are in good health and both the size and the condition of the ornament are heritable.

More and more evidence indicates the most changeable part of the environment consists of parasites, bacteria and viruses, said Mans Andersson, who directs the research team. All of these, especially viruses, evolve more rapidly than the hosts whose resources they live off of. The host will therefore always be in an important evolutionary race against its diseases.

The study is detailed in the journal Acta Zoologica.