Encyclopedia of Evolutionary Psychological Science

Living Edition
| Editors: Todd K. Shackelford, Viviana A. Weekes-Shackelford

Vigilance, Sentinels, and Alarms

Living reference work entry
DOI: https://doi.org/10.1007/978-3-319-16999-6_2704-1



Vigilance is attentive behavior directed at an animal’s surroundings to detect or monitor perceived dangers. Sentinels are individuals in a social group that scan the surroundings while groupmates are engaged in other activities nearby. Alarm calls are vocalizations given by animals in response to perceived danger from predators.


Predation is a fundamentally important selective pressure.

Given the large fitness costs of failing to detect and avoid predators, there should be strong selective pressure for behaviors that enable the early detection of possible threats.


Vigilance involves scanning the environment for possible dangers. Despite its clear individual benefits, vigilance may have significant opportunity costs in the form of time taken away from other important activities, such as foraging, mating, and socializing. Accordingly, vigilance may have chronic effects on individual fitness. Thus, if predation risk varies...

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Authors and Affiliations

  1. 1.Tulane UniversityNew OrleansUSA

Section editors and affiliations

  • Russell Jackson
    • 1
  1. 1.University of IdahoMoscowUSA