Léo Grasset

“Many bird species incorporate coloured plastic detritus when building their nests (...), using the bright colours as signals to neighbouring birds or to attract females. (...) the largest individuals with the best territories use more plastic in their nests than weaker individuals with less desirable territories. This eye-catching display reduces conflict: each individual can size up a rival´s strenght at a glance, and so avoid getting into fights in which they are likely to be beaten.”
― Léo Grasset, How the Zebra Got Its Stripes