The Use of Niche Breadth and Proportional Similarity in Feeding to Stipulate Resource Utilization Strategies in Fish

Abstract

ABSTRACT A hypothetical data set was evaluated using algorithms to calculate niche breadth (Levins' index) and the proportional similarity in feeding between the species of interest and the resource base (the PS ratio of Feinsinger et al.). The results were then examined for the occurrence of concordance and non-concordance between information generated by these two algorithms. The nature of the concordance and non-concordance can be used to define strategies of resource utilization. That is, if the concordance results from both a high niche breadth value and a high proportional similarity in feeding, the foraging strategy is that of a classic “generalist.” If the values for proportional similarity in feeding and the niche breadth are both low, the foraging strategy is that of a classic “specialist.” In cases of non-concordance where the values for niche breadth is high but the value for proportional feeding is low, the foraging strategy is that of a “selectionist.” But if the niche breadth value is low a...