All clear? Meerkats attend to contextual information in close calls to coordinate vigilance

@article{Townsend2011AllCM,
  title={All clear? Meerkats attend to contextual information in close calls to coordinate vigilance},
  author={Simon W. Townsend and Markus Z{\"o}ttl and Marta B. Manser},
  journal={Behavioral Ecology and Sociobiology},
  year={2011},
  volume={65},
  pages={1927-1934}
}
Socio-demographic factors, such as group size and their effect on predation vulnerability, have, in addition to intrinsic factors, dominated as explanations when attempting to understand animal vigilance behaviour. It is generally assumed that animals evaluate these external factors visually; however, many socially foraging species adopt a foraging technique that directly compromises the visual system. In these instances, such species may instead rely more on the acoustical medium to assess… 
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