Diet specialization in a fluctuating population of Saduria entomon: a consequence of resource or forager densities?
Version of Record online: 18 OCT 2010
© 2011 The Authors
Volume 120, Issue 6, pages 848–854, June 2011
How to Cite
Svanbäck, R., Rydberg, C., Leonardsson, K. and Englund, G. (2011), Diet specialization in a fluctuating population of Saduria entomon: a consequence of resource or forager densities?. Oikos, 120: 848–854. doi: 10.1111/j.1600-0706.2010.18945.x
- Issue online: 23 MAY 2011
- Version of Record online: 18 OCT 2010
- Paper manuscript accepted 1 September 2010
Intraspecific competition has been shown to favor diet specialization among individuals. However, the question whether the competition takes the form of interference or exploitative in driving diet specialization has never been investigated. We investigated individual diet specialization in the isopod Saduria entomon, in relation to forager and resource biomasses in a system that exhibits predator–prey fluctuations in density. We found that individual diet specialization was only affected by the biomass of their preferred prey (Monoporeia affinis) and not by Saduria biomass; diet specialization was higher when Monoporeia biomass was low compared to when there were high Monoporeia biomass. Population diet breadth increased at low Monoporeia biomass whereas individual diet breadths were marginally affected by Monoporeia biomass. Overall, this led to the increase in diet specialization at low Monoporeia biomass. This study shows that predator–prey dynamics might influence diet specialization in the predator and that resource biomass, not forager biomass might be important for individual diet specialization.