Data from: Plant functional traits reveal the relative contribution of habitat and food preferences to the diet of grasshoppers

Food preferences and food availability are two major determinants of the diet of generalist herbivores and of their spatial distribution. How do these factors interact and eventually lead to diet differentiation in co-occurring herbivores? We quantified the diet of four grasshopper species co-occurring in subalpine grasslands using DNA barcoding of the plants contained in the faeces of individuals sampled in the field. The food preferences of each grasshopper species were assessed by a choice (cafeteria) experiment from among 24 plant species common in five grassland plots, in which the four grasshoppers were collected, while the habitat was described by the relative abundance of plant species in the grassland plots. Plant species were characterised by their leaf economics spectrum (LES), quantifying their nutrient vs. structural tissue content. The grasshoppers' diet, described by the mean LES of the plants eaten, could be explained by their plant preferences but not by the available plants in their habitat. The diet differed significantly across four grasshopper species pairs out of six, which validates food preferences assessed in standardised conditions as indicators for diet partitioning in nature. In contrast, variation of the functional diversity (FD) for LES in the diet was mostly correlated to the FD of the available plants in the habitat, suggesting that diet mixing depends on the environment and is not an intrinsic property of the grasshopper species. This study sheds light on the mechanisms determining the feeding niche of herbivores, showing that food preferences influence niche position whereas habitat diversity affects niche breadth.gh raw data in fasta formatThis fasta file contains all the different sequences amplified with the gh primer pair, sorted by decreasing order of count, and with the information about the fecal samples they come from.Acrididae_gh_uniq_sort_c1.fastaITSAst raw data in fasta formatThis fasta file contains all the different sequences amplified with the ITSAst primer pair, sorted by decreasing order of count, and with the information about the fecal samples they come from.Acrididae_ITSAst_uniq_sort_c1.fastaITSCyp raw data in fasta formatThis fasta file contains all the different sequences amplified with the ITSCyp primer pair, sorted by decreasing order of count, and with the information about the fecal samples they come from.Acrididae_ITSCyp_uniq_sort_c1.fastaITSPoa raw data in fasta formatThis fasta file contains all the different sequences amplified with the ITSPoa primer pair, sorted by decreasing order of count, and with the information about the fecal samples they come from.Acrididae_ITSPoa_uniq_sort_c1.fastagh filtered data in tabulated formatThis text tabulated file contains all the filtered sequences amplified with the gh primer pair. For each sequence, this table gives the number of occurrences per sample.Acrididae_gh_filtered.txtITSAst filtered data in tabulated formatThis text tabulated file contains all the filtered sequences amplified with the ITS1-F and ITS1Ast-R primers. For each sequence, this table gives the number of occurrences per sample.Acrididae_ITSAst_filtered.txtITSCyp filtered data in tabulated formatThis text tabulated file contains all the filtered sequences amplified with the ITS1-F and ITS1Cyp-R primers. For each sequence, this table gives the number of occurrences per sample.Acrididae_ITSCyp_filtered.txtITSPoa filtered data in tabulated formatThis text tabulated file contains all the filtered sequences amplified with the ITS1-F and ITS1Poa-R primers. For each sequence, this table gives the number of occurrences per sample.Acrididae_ITSPoa_filtered.tx