Direct look from a predator shortens the risk-assessment time by prey.

Sang-Im Lee,Hyeon-Jeong Lee,Young-Eun Joe,Soyun Hwang,Hyun-Kyung Cha,Ji-Won Kim,Gun-Ho Joo,Piotr G Jablonski,Daniel Osorio

doi:10.1371/journal.pone.0064977

Abstract

Decision making process is an important component of information use by animals and has already been studied in natural situations. Decision making takes time, which is expressed as a cost in evolutionary explanations of decision making abilities of animals. However, the duration of information assessment and decision making process has not been measured in a natural situation. Here, we use responses of wild magpies (Pica pica) to predictably approaching humans to demonstrate that, regardless of whether the bird perceived high (decided to fly away) or low (resumed foraging) threat level, the bird assessed the situation faster when approaching humans looked directly at it than when the humans were not directly looking at it. This indicates that prey is able to extract more information about the predator’s intentions and to respond sooner when the predator is continuously (“intently”) looking at the prey. The results generally illustrate how an increase of information available to an individual leads to a shorter assessment and decision making process, confirming one of central tenets of psychology of information use in a wild bird species in its natural habitat.

Highlights

Processes of assessment and decision making [1,2,3,4] have been studied in natural situations in various contexts including mate choice [5,6,7], habitat choice [8,9,10] and foraging [11,12,13]
The studies of prey decision making based on more complex assessment processes have mostly focused on determining the assessment rules (e.g. [24,25,26,27]), perhaps because the assessment rules are at the center of attention in neurobiology [28], evolutionary psychology [29] or cognitive ecology [30]
The costs of decision making process, such as the time required for risk assessment, are important for the theory of information use in ecology [2]

Summary

Introduction

Processes of assessment and decision making [1,2,3,4] have been studied in natural situations in various contexts including mate choice [5,6,7], habitat choice [8,9,10] and foraging [11,12,13]. The studies of prey decision making based on more complex assessment processes (cognitive processes rather than simple mechanisms such like prey escape responses to looming stimuli [17,18,19,20,21,22,23]) have mostly focused on determining the assessment rules [24,25,26,27]), perhaps because the assessment rules are at the center of attention in neurobiology [28], evolutionary psychology [29] or cognitive ecology [30] They are important for adaptive interpretations of prey flight initiation distances The time required for assessment and its influence on decision making process have not been determined in natural situations and have not been explicitly incorporated in the classical theoretical models of escape behavior (e.g. [14], [16], [33])

Methods

Results

Conclusion