Behavioral Ecology and Sociobiology

, Volume 59, Issue 1, pp 84–91 | Cite as

Social cohesion and foraging decrease with group size in fallow deer (Dama dama)

  • Stefano FocardiEmail author
  • Elena Pecchioli
Original Article


We studied the impact of group size on foraging behaviour and level of movement synchronisation among female herdmates of a fallow deer population in Central Italy. Both proportion of foraging events and movement synchronisation decreased with increasing group size. The proportion of foraging events was higher for animals on the edge of the group than for deer in the centre of the group; hence, there appears to be a trade-off between protection against predators and foraging interference, both of which decrease from the centre to the periphery of the group. This is the first time this type of behaviour has been recorded for wild ungulates. As expected, we also found that the movement of peripheral animals was less synchronised than that of central animals. Consequently, peripheral animals may lose contact with their herdmates and split off the group. We conclude that social inequalities may lead to conflicting requirements among group members and instability of large groups. Movement synchronisation (as a function of group size) appears to interact with habitat openness to produce variations of group size (which appear to be adaptive for individuals) as an emergent property of these aggregations.


Fallow deer Dama dama Aggregation dynamics Foraging interference Movement synchronisation 



We thank the Segretariato alla Presidenza della Repubblica for permission to work at Castelporziano and P Montanaro for helping with field work. JF Gerard reviewed a first draft of the paper and gave us relevant comments. M Festa Bianchet and an anonymous referee provided useful comments and corrections to the manuscript. HC Hauffe corrected the final manuscript


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Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  1. 1.Istituto Nazionale per la Fauna SelvaticaOzzano dell'EmiliaItaly
  2. 2.Centre for Alpine EcologyTrentoItaly

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