Animal Sentience

Commentary Type

Invited Commentary


We discuss fear and vigilance from the perspective of foraging theory. Rather than focusing on proximate indicators of fear, we suggest that fear is an adaptation for assigning a cost to activities that incur a risk of injury or death. We use theory to provide definitions for fear and vigilance and then use that theory to compare them. We agree that there are limits to the reliability of vigilance as an indicator of fear, but we arrive at this conclusion differently.

Author Biography

Burt P. Kotler, Professor of desert ecology at Ben-Gurion University of the Negev, studies behaviors and other traits of organisms as adaptations in the tradeoffs between food and safety. He applies this to foraging behavior, risk management, mechanisms of species coexistence and predator-prey foraging games.


Joel S. Brown, Distinguished Professor Emeritus of Biological Sciences at the University of Illinois at Chicago, is an “optimist” who uses optimization and evolutionary game theory to understand ecological phenomena from cancer dynamics to intercontinental community convergence.