Differential Survival In Carrion Crows Through Eavesdropping on Human Speech: An Agent-Based Model

Abstract

Wild carrion crows eavesdrop on human speech and respond more strongly to it than to the calls of pigeons or parakeets. However, it remains unclear whether this behaviour provides any benefit to them, and if so, under which environmental conditions such a benefit could be expected. I used an agent-based model to examine the effect of eavesdropping on the survival of a carrion crow under different environmental conditions. The crow could gain points from foraging, but also had to avoid encounters with a human in order to not lose points. In addition to eavesdropping, it could visually scan the patch for human presence and, once detected, could keep track of the humans location. I found that eavesdropping led to higher final scores and higher rates of survival than visual scanning alone if the human density on the patch was elevated, or if there were visual obstacles reducing the accuracy of visual scans. Such environmental conditions are particularly common for urban crows foraging in areas such as public parks. The model provides a proof of concept for future empirical research into the potentially differential survival of urban crows eavesdropping on speech.