Birds use their beaks for foraging, but also for regulating their temperature, singing and a variety of other functions. Do beaks and other multifunctional traits have characteristics that are specialized for each function, or are they an evolutionary compromise? To test this, we examined beak shape and size in a family of Australian songbirds, and compared the influence of each function on the evolution of species differences. We found that foraging behaviour and climate both have an effect on the evolution of bird beaks and their characteristics, and that this also affects features of the songs these birds perform.
Listen to the call of Philemon corniculatus (commonly known as the Noisy Friarbird) below!