In the world of birds, where fancy can be as fleeting as flight, the color of the bird apparently has a profound effect on more than just its image. A new study of barn swallows reveals it also affects the bird's physiology.
A team of researchers, including one from Arizona State University, found in an experiment that involved artificially coloring the breast feathers of male barn swallows the testosterone levels of the manipulated birds soared in a short period of time. The jump in testosterone, recorded after one week, was unexpected because it was observed at the time in the breeding cycle when levels of sex steroids like testosterone are typically declining.
"The traditional view is that internal processes of birds determine their external features -- in other words, physiology forms the feathers," said Kevin McGraw, an assistant professor at ASU's School of Life Sciences. "But our results indicate that a perceived change in the color of an animal can directly affect its internal physiological state. A barn swallow's hormonal profile is influenced by its outward appearance."
Click here for the full article.
Loading ...
