Skip Navigation



Behavioral Ecology Advance Access published online on September 29, 2004
Behavioral Ecology, doi:10.1093/beheco/arh169
© 2004 by International Society for Behavioral Ecology
This Article
Right arrow FREE Full Text (PDF) Freely available
Right arrow Lay Summary
Right arrow All Versions of this Article:
16/2/352    most recent
arh169v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Beauchamp, G.
Right arrow Articles by Fernández-Juricic, E.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Beauchamp, G.
Right arrow Articles by Fernández-Juricic, E.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Received May 31, 2004
Revised August 25, 2004
Accepted September 10, 2004

Article

The group-size paradox: effects of learning and patch departure rules

Guy Beauchamp 1* and Esteban Fernández-Juricic 2

1 Faculty of Veterinary Medicine, University of Montréal, P.O. Box 5000, St-Hyacinthe, Québec J2S 7C6, Canada
2 Department of Biological Sciences, California State University Long Beach, Peterson Hall 1-109, 1250 Bellflower Blvd, Long Beach, CA 90840, USA

* To whom correspondence should be addressed. E-mail: guy.beauchamp{at}umontreal.ca.


  Abstract

In many species, foraging in groups can enhance individual fitness. However, groups are often predicted to be larger than the size that maximizes individual fitness. This is because individual foragers are expected to continue joining a group until the fitness in the group falls to the level experienced by solitary foragers. If such a process were pervasive, social foraging, paradoxically, would provide little evolutionary advantages. We propose a solution to the group-size paradox by allowing foragers to learn about habitat quality and leave food patches when their current intake rate falls below that expected for the whole habitat. By using a simulation model, we show that under a wide range of population sizes, foragers using such rules abandon under- and overcrowded patches, ensuring that group size remains close to the optimal value. The results hold in habitats with varying patch quality, but we note that the lack of food renewal in patches can disrupt the process of group formation. We conclude that groups of optimal sizes can occur frequently if fitness functions are peaked and resources patchily distributed, without the need to invoke relatedness between joiners and established group members, group defense against joiners, or other mechanisms that were proposed earlier to prevent groups from becoming too large.

Keywords: learning; linear operator rule; optimal group size; simulation model; social foraging.
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Behav EcolHome page
A. L. Jackson and G. D. Ruxton
Toward an individual-level understanding of vigilance: the role of social information
Behav. Ecol., July 1, 2006; 17(4): 532 - 538.
[Abstract] [Full Text] [PDF]

Home page
 Behav EcolHome page
G. Beauchamp and G. D. Ruxton
Harvesting resources in groups or alone: the case of renewing patches
Behav. Ecol., November 1, 2005; 16(6): 989 - 993.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.