Cognitive maps in the wild: revealing the use of metric information in black howler monkey route navigation.

Miguel De Guinea,Sarie Van Belle,K Anne-Isola Nekaris,Alejandro Estrada

doi:10.1242/jeb.242430

Abstract

ABSTRACTWhen navigating, wild animals rely on internal representations of the external world – called ‘cognitive maps’ – to take movement decisions. Generally, flexible navigation is hypothesized to be supported by sophisticated spatial skills (i.e. Euclidean cognitive maps); however, constrained movements along habitual routes are the most commonly reported navigation strategy. Even though incorporating metric information (i.e. distances and angles between locations) in route-based cognitive maps would likely enhance an animal's navigation efficiency, there has been no evidence of this strategy reported for non-human animals to date. Here, we examined the properties of the cognitive map used by a wild population of primates by testing a series of cognitive hypotheses against spatially explicit movement simulations. We collected 3104 h of ranging and behavioural data on five groups of black howler monkeys (Alouatta pigra) at Palenque National Park, Mexico, from September 2016 through August 2017. We simulated correlated random walks mimicking the ranging behaviour of the study subjects and tested for differences between observed and simulated movement patterns. Our results indicated that black howler monkeys engaged in constrained movement patterns characterized by a high path recursion tendency, which limited their capacity to travel in straight lines and approach feeding trees from multiple directions. In addition, we found that the structure of observed route networks was more complex and efficient than simulated route networks, suggesting that black howler monkeys incorporate metric information into their cognitive map. Our findings not only expand the use of metric information during route navigation to non-human animals, but also highlight the importance of considering efficient route-based navigation as a cognitively demanding mechanism.

Highlights

IntroductionAnimals have developed a wide variety of navigational strategies to make use of environmental information and reach relevant biological locations (e.g. celestial cues to orientate migratory routes: Foster et al, 2018; visual landmarks associated to foraging sites: Zeil, 2012; path integration using nest location as reference: Heinze et al, 2018)
In this study, we used a novel approach to investigate navigation strategies of black howler monkeys by comparing observed movement patterns with computer-generated random movement patterns, which acted as a control
While these findings discard the use of a Euclidean cognitive map in black howler monkeys, the highly efficient structure of the observed networks in comparison to simulated networks suggests that black howler monkeys rely on a labelled graph cognitive map rather than a topological map to navigate

Summary

Introduction

Animals have developed a wide variety of navigational strategies to make use of environmental information and reach relevant biological locations (e.g. celestial cues to orientate migratory routes: Foster et al, 2018; visual landmarks associated to foraging sites: Zeil, 2012; path integration using nest location as reference: Heinze et al, 2018). Among these navigational strategies, some species generate internal representations of the space wherein they live, known as ‘cognitive maps’ (Tolman, 1948). Sophisticated cognitive maps likely support flexible and efficient movement patterns that enhance foraging efforts of individuals or groups (Behrens et al, 2018; Milton, 1981)

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Conclusion