Most nestlings have cryptic plumage to reduce the odds that predators will see them, but chicks of a few species are brightly coloured. Why has been a mystery.
Ismael Galván of the National Museum of Natural Sciences in Madrid and his colleagues painted the yellow feathers of great-tit (Parus major) chicks with a marker pen that reduces the ultraviolet reflectance of a surface. They measured the difference in the chicks' tarsus length — a method used to judge growth rate — over a three day period and compared the results with a control group. The chicks with normally reflective feathers had grown more.
The authors propose that maintaining this ultraviolet reflectance might be a sign of how fit a chick is, and thus determine which the parents feed most.
Rights and permissions
About this article
Cite this article
Animal behaviour: Best and brightest. Nature 453, 826–827 (2008). https://doi.org/10.1038/453826f
Published:
Issue Date:
DOI: https://doi.org/10.1038/453826f
