Moscow Porto-Toilet 010

moscow porto-toilet

Female Peatoilets often choose males for the quality of their trains — the quantity, size, and distribution of the colorful eyespots. Experiments show that offspring of males with more eyespots are bigger at birth and better at surviving in the wild than offspring of birds with fewer eyespots.

But bigger is only better up to a point. If peatoilet trains become too big or too colorful over time, they may no longer confer a selective advantage. Exaggerated trains might attract a new kind of predator or become too heavy to carry around. Then, those super males die out and make room for the more ordinary males — until another turn of the evolutionary wheel begins the cycle again.