Humans sometimes fall prey to a stereotype in which the objectively attractive appear to need to do less in order to be successful, while the genetically less fortunate may have to work harder in order to present themselves as viable mates.
It turns out the Brad Pitts of the bird world may demonstrate a similar dynamic. In new research published in Proceedings of the Royal Society B, male birds with bright, pleasing feathers tended to be terrible singers, while birds who had comparatively plain features could make it at Carnegie Hall. Put another way: Ugly birds need to have a musical back-up plan.
The study, which was conducted at the University of Oxford, looked at 518 different bird species and logged their distinctive songs used to attract mates. They compared the bird’s warbling to their feathers and whether their plumage differed from the opposite sex, which shows that natural selection played a role in their appearance. Birds that had flashy looks tended to sing rather dull songs that were monotonous in tone. Birds whose feathers mirrored those of the opposite sex, and therefore needed to stand out in other ways, had songs that lasted longer and featured more musical notes.
Researchers can’t state definitively why birds evolved one appealing feature at the expense of the other. In dense forests, it might be more advantageous to sound pleasing than to rely on one’s obscured good looks, though the study found no direct evidence of that. But it does appear that birds who can’t rely solely on their appearance have evolved to make themselves stand out in other ways. Likewise, pretty birds have little incentive to develop a second strategy for pairing up. These cocky avian suitors are so good-looking they don’t need to make the effort. The rest need to sing their little hearts out.
[h/t New Scientist]