If a research team at Uppsala University, Sweden has to be believed beauty is the weapon against bird flu. They have shown as a study published in the journal Acta Zoologica, that the size of the spot on a male collared flycatcher's forehead reflects how well the immune defence system combats viruses such as avian influenza. The white spot is also attractive to female birds searching for a mate.
In many species both males and females prefer to mate with those who have the largest or most colourful of these ornaments or who have the most complex song, for instance.
MŚns Andersson, who directs the research team said, "More and more evidence indicates that the most changeable part of the environment consists of parasites, bacteria and viruses. 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. Thus it seems that the female uses the forehead spot as a health indicator. When she chooses males with a large forehead spots, she takes not only the healthiest males but also the ones with the best immune defence against future virus infections."
The male collared flycatcher can change the size of the forehead spot during the mating season and that males that unfurl their forehead spots most are those that produce the most antibodies informs the study.