Eleanor Brush (University of Maryland)
Abstract. Signaling systems can help animals overcome some of the challenges of living in social groups. For example, many birds use songs to recognize other members of their species and to decide with whom to mate. Another example is given by the visible signals or badges many animals use to assess the ability or quality of a group mate. In this talk, I will present mathematical models of two signaling systems that can help us understand both the evolutionary consequences of using different signaling systems and when a particular signaling system might evolve. First, I will discuss a model of song evolution in birds. In this model, the diversity of songs present at an evolutionary equilibrium depends strongly on whether songs and preferences are learned or genetically inherited. This has implications for how song learning might affect allopatric speciation in birds. Second, I will discuss a model in which each member of a social group seeks to learn about the quality of each of its peers. We find that whether a badge system or an individual recognition system is more reliable depends on the group's size, its stability, and the cognitive ability of the animals. In particular, an intermediate cognitive ability maximizes the reliability of the badge system.