Animal Cognition

, Volume 11, Issue 3, pp 441–448 | Cite as

Female degus (Octodon degus) monitor their environment while foraging socially

  • Verónica Quirici
  • Rodrigo A. Castro
  • Javiera Oyarzún
  • Luis A. Ebensperger
Original Paper

Abstract

Vigilance or scanning involves interruptions in foraging behavior when individuals lift their heads and conduct visual monitoring of the environment. Theoretical considerations assume that foraging with the “head down”, and scanning (“head up”) are mutually exclusive activities, such that foraging precludes vigilance. We tested this generalization in a socially foraging, small mammal model, the diurnal Chilean degu (Octodon degus). We studied spontaneous bouts of scanning of captive degus when foraging in pairs of female sibs and non-sibs. We examined the extent to which foraging (head down postures) and scanning (head up postures) were mutually exclusive in subjects exposed to none, partial, and complete lateral visual obstruction of their partners. In addition, we monitored the orientation of their bodies to examine the target of attention while foraging and scanning. Lastly, we examined the temporal occurrence of scanning events to assess the extent of scanning coordination, and whether this coordination is kin-biased. Visual obstruction had a significant influence on degu vigilance. Focal degus increased their quadrupedal and semi-erect scanning when foraging under a partially obstructed view of their partners. Degus oriented their bodies toward partners when foraging and scanning. Despite this, degus did not coordinate scanning bouts; instead, they scanned independently from one another. Relatedness among cage mates did not influence any aspect of degu behavior. Contrary to theoretical expectations, these results indicate that foraging and vigilance are not mutually exclusive, and that kinship per se does not influence scanning behavior and coordination.

Keywords

Social foraging Scanning Visual obstruction Vigilance coordination Degus 

Notes

Acknowledgments

We are particularly indebted to our colleagues Antonio Hargreaves and Cristián Bonacic from the Departamento de Zootecnia, Facultad de Agronomía e Ingeniería Forestal (PUC) for providing the space facilities to carry out our research. Thanks to Carlota Lara for helping during the initial setting up of housing facilities. Funding was provided by a FONDECYT grant 1020861 to LAE. During the writing of this article, LAE was supported by the Center for Advanced Studies in Ecology and Biodiversity (FONDAP 1501-001). We appreciate the statistical advice provided by our colleagues Sergio Estay and Laurent Crespin, and comments by Diego Bustamante, Loren Hayes, Peter Bednekoff and two anonymous reviewers to previous versions of the manuscript. All research conducted as part of this study conformed to national and institutional guidelines for research on live mammals (permits 893 and 1894 by the Servicio Agrícola y Ganadero, SAG).

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Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Verónica Quirici
    • 1
  • Rodrigo A. Castro
    • 1
  • Javiera Oyarzún
    • 1
  • Luis A. Ebensperger
    • 1
  1. 1.Departamento de Ecología and Centro de Estudios Avanzados en Ecología and Biodiversidad, Facultad de Ciencias BiológicasPontificia Universidad Católica de ChileSantiagoChile

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