A new approach to graphical analysis of feeding strategy from stomach contents data : modification of the Costello (1990) method

A modification of the graphical Costello method is proposed for the analysis of stomach contents data. The new method allows prey importance, feeding strategy and the inter- and intra-individual components of niche width to be explored using graphical presentation. The analysis is based on a two-dimensional representation of prey-specific abundance and frequency of occurrence of the different prey types in the diet. The paper describes the new method and the parameters therein, and also present some examples of the utilization of the method. The method may be particularly well-suited for the examination of predictions made from optimal foraging, competition and niche theories.