Kraaijeveld, Ken; Gregurke, John; Hall, Carol; Komdeur, Jan - In: Behavioral Ecology 15 (2004) 3, pp. 380-389
We investigated the adaptive significance of a sexually monomorphic ornament in the black swan Cygnus atratus. Both sexes grow curled feathers on their wings (range 7--22 curled feathers per wing), which are displayed prominently in a range of social interactions. The number of curled feathers...