Foraging efficiency in temporally predictable environments: is a long-term temporal memory really advantageous?

Benjamin Robira,Simon Benhamou,Louise Riotte-Lambert,Violaine Llaurens,Shelly Masi

doi:10.1098/rsos.210809

Abstract

Cognitive abilities enabling animals that feed on ephemeral but yearly renewable resources to infer when resources are available may have been favoured by natural selection, but the magnitude of the benefits brought by these abilities remains poorly known. Using computer simulations, we compared the efficiencies of three main types of foragers with different abilities to process temporal information, in spatially and/or temporally homogeneous or heterogeneous environments. One was endowed with a sampling memory, which stores recent experience about the availability of the different food types. The other two were endowed with a chronological or associative memory, which stores long-term temporal information about absolute times of these availabilities or delays between them, respectively. To determine the range of possible efficiencies, we also simulated a forager without temporal cognition but which simply targeted the closest and possibly empty food sources, and a perfectly prescient forager, able to know at any time which food source was effectively providing food. The sampling, associative and chronological foragers were far more efficient than the forager without temporal cognition in temporally predictable environments, and interestingly, their efficiencies increased with the level of temporal heterogeneity. The use of a long-term temporal memory results in a foraging efficiency up to 1.16 times better (chronological memory) or 1.14 times worse (associative memory) than the use of a simple sampling memory. Our results thus show that, for everyday foraging, a long-term temporal memory did not provide a clear benefit over a simple short-term memory that keeps track of the current resource availability. Long-term temporal memories may therefore have emerged in contexts where short-term temporal cognition is useless, i.e. when the anticipation of future environmental changes is strongly needed.

Highlights

As the local density of resources changes both in time and space, numerous animal species have evolved abilities to process and memorize information towards reducing uncertainties about the spatio-temporal resource distribution [1,2]
This dramatically limits our understanding of the selection pressure that acts on temporal cognition
As the contributions of spatial/attribute memory and temporal memory to foraging efficiency were likely to be independent of each other, we considered for simplicity, but without the loss of generality, that animals were endowed with an accurate spatial/attribute memory, i.e. they perfectly knew the locations of the potential food sources and the type of resource provided at each location, but differed by their abilities to infer when resource was available

Summary

Introduction

As the local density of resources changes both in time and space, numerous animal species have evolved abilities to process and memorize information towards reducing uncertainties about the spatio-temporal resource distribution [1,2]. A forager with such abilities is not limited to just resolve when it should leave a profitable place [3,4] to maximize its efficiency. It can take advantage of its previous experience to infer where (at which location), what (which type of resource) and when (at which time) resources occur. The comparative benefits that a forager may obtain by relying on different types of temporal memory remain poorly known. This dramatically limits our understanding of the selection pressure that acts on temporal cognition

Methods

Results

Conclusion