Fig. 2

Variable selection and evolution of the hFI’s effect size in models with increasing complexity. The x axis shows the variables sequentially included in the model during forward model selection (ordered by most frequent selection order during the 30 repetitions). The final models (respectively for hFI = –HS, MT and –1000/RT, left to right columns) were chosen as the ones including all covariates selected more than a third of the times (horizontal dashed line) using a p-value threshold of 0.05 (black bars, a). The procedure was run with a p-value threshold of 0.01 for comparison (grey bars, a). The changes in the effect size of each of the hFIs with increasing model complexity is presented in (b), with values for the different levels of Ptactic (benthic and pelagic) and for 25 and 50 m dive depth. Grey shadings show the 95 % bootstrapped confidence intervals of the effect size