Data from: Consumer interaction strength may limit the diversifying effect of intraspecific competition: a test in alewife (Alosa pseudoharengus).
Jones, Andrew W.; Post, David M. (2013), Data from: Consumer interaction strength may limit the diversifying effect of intraspecific competition: a test in alewife (Alosa pseudoharengus)., Dryad, Dataset, https://doi.org/10.5061/dryad.r4sj0
Intraspecific competition is considered a principal driver of dietary variation, however, empirical studies provide mixed support for this mechanism. Here we link comparative and experimental work testing the effects of competition and resource availability on the dietary variation of alewife (Alosa pseudoharengus). Alewife, a consumer with extreme effects on its resources, are specifically utilized to additionally test the idea that that the strength of the interaction between a consumer and its resources may diminish the diversifying effect of competition. First, we compared the short- and long-term diet measures of from wild populations across a range of densities. Second, in a series of large-scale field mesocosm experiments we explored the influence of competition and interaction strength on alewife dietary variation. Results from the whole lake comparison and field experiments indicated that increasing competition was negatively correlated with population dietary variation. Further, altering the strength of the interaction between alewife and their prey via prey supplementation eliminated this negative relationship. Collectively, our results suggest that competitive interactions may not drive dietary diversification in highly effective consumers. Our results also suggest that further consideration of the strength of species interactions (and the consumer traits that underlie them) would improve our understanding of the link between intraspecific competition and variation