A successful season of fieldwork has seen the collection of more genetic samples from Tawny-flanked prinias by Gabriel Jamie, as well as egg rejection experiments conducted by Tanmay Dixit. Jess Lund continued experiments on the colouration of Cuckoo finch chicks, started in 2018 by Jana Riederer. As always, field research was supported on a daily basis by Collins Moya and Silky Hamama, here with Gabriel in our study area at Semhawa Farm.
Our paper ‘Why and how to apply Weber’s Law to coevolution and mimicry’ has been published in the journal Evolution. This perspectives paper, written by Tanmay Dixit, Eleanor Caves, Claire Spottiswoode, and Nicholas Horrocks, argues that Weber’s Law of proportional processing can lead to otherwise counterintuitive predictions about the evolutionary trajectories of mimicry systems. Weber’s Law states that when the magnitude of a stimulus is large, it is more difficult to discriminate a change or difference from that stimulus. In other words, relative differences are more salient than absolute differences. We show that Weber’s Law could have implications for mimicry: when stimulus magnitudes are high, it should be more difficult to discriminate a model from a mimic. This leads to testable predictions about evolutionary trajectories of models and mimics. We also present a framework for testing Weber’s Law and its implications for coevolution.