Artículo de revista
A network-based approach to the analysis of ontogenetic diet shifts: An example with an endangered, small-sized fish
Fecha
2011Registro en:
Ecological Complexity 8 (2011) 123–129
doi:10.1016/j.ecocom.2010.11.005
Autor
Ramos Jiliberto, Rodrigo
Valdovinos, Fernanda S.
Arias, Jonathan
Alcaraz, Carles
García Berthou, Emili
Institución
Resumen
Many organisms exhibit ontogenetic shifts in their diet and habitat use, which often exert a large
influence on the structure and expected dynamics of food webs and ecological communities.
Nevertheless, reliable methods for detecting these niche shifts from consumption data are limited. In this
study we present a new approach for the detection and analysis of ontogenetic diet shifts, based on
complex network theory. As a case study, we apply these methods to the endangered, small fish Aphanius
iberus. The stage-structured consumer population and its set of consumed prey are represented as an
unweighted bipartite network. A statistical evaluation of the resulting network structure permits to
uncover empirical patterns of ontogenetic diet shifts. We test for changes in niche breadth, as well as
nestedness and diet modularity along ontogeny. These tests were carried out on the subnetworks
describing consumption, positive electivity, and negative electivity on prey items. The statistical
significance was established by means of null model analyses. Our analyses reveal a nested diet, along
with a gradual decrease in diet breadth and a modular structure (i.e. abrupt changes) of elected preys
along the ontogeny of A. iberus. The detection of network structure by means of the use of tools from
complex network theory is shown to be a promising method for studying ontogenetic niche shifts.