How shoud prey animals respond to uncertain threats?

TL;DR

This paper develops a probabilistic model to determine optimal escape responses of prey animals under environmental uncertainty, supported by simulations showing evolved strategies align with the model's predictions.

Contribution

It introduces the first theoretical framework incorporating uncertainty into prey escape decision-making and validates it through evolutionary simulations.

Findings

Optimal escape strategies depend heavily on environmental uncertainty.

Simulated populations evolve strategies consistent with the model's predictions.

The model confirms the importance of uncertainty in decision-making processes.

Abstract

A prey animal surveying its environment must decide whether there is a dangerous predator present or not. If there is, it may flee. Flight has an associated cost, so the animal should not flee if there is no danger. However, the prey animal cannot know the state of its environment with certainty, and is thus bound to make some errors. We formulate a probabilistic automaton model of a prey animal's life and use it to compute the optimal escape decision strategy, subject to the animal's uncertainty. The uncertainty is a major factor in determining the decision strategy: only in the presence of uncertainty do economic factors (like mating opportunities lost due to flight) influence the decision. We performed computer simulations and found that \emph{in silico} populations of animals subject to predation evolve to display the strategies predicted by our model, confirming our choice of objective function for our analytic calculations. To the best of our knowledge, this is the first theoretical study of escape decisions to incorporate the effects of uncertainty, and to demonstrate the correctness of the objective function used in the model.