DOI: 10.5061/dryad.kb874
title: Data from: Ecological explanations to island gigantism: dietary niche divergence, predation and size in an endemic lizard

description: Although rapid evolution of body size on islands has long been known, the
 ecological mechanisms behind this island phenomenon remain poorly
 understood. Diet is an important selective pressure for morphological
 divergence. Here we investigate if selection for novel diets has
 contributed to the multiple independent cases of island gigantism in the
 Skyros wall lizard (Podarcis gaigeae) and if diet, predation, or both
 factors best explain island gigantism. We combined data on body size,
 shape, bite force, and realized and available diets to address this.
 Several lines of evidence suggest that diet has contributed to the island
 gigantism. The larger islet lizards have relatively wider heads and higher
 bite performance in relation to mainland lizards than would be expected
 from size differences alone. The proportions of consumed and available
 hard prey are higher on islets than mainland localities, and lizard body
 size is significantly correlated with the proportion of hard prey.
 Furthermore, the main axis of divergence in head shape is significantly
 correlated with dietary divergence. Finally, a model with only diet and
 one including diet and predation regime explain body size divergence
 equally well. Our results suggest that diet is an important ecological
 factor behind insular body size divergence, but could be consistent with
 an additional role for predation.
description: README_Runemark_et_alReadme file containing descriptions of the files deposited for this manuscriptGeographic_locations_Runemark_et_alA table of the geographic coordinates and population names.Microsatellite_data_Runemark_et_alA file containing the raw microsatellite data Fst calculations for the paper were based on. Population affinity is denoted by the codes used on the map in Figure 1 in the paper and the table in Geographic_locations_Runemark_et_al.txtSVL_headwidth_Runemark_et_alContains information on Snout-vent length and head width per individuals. Population affinity is denoted by the population codes from Figure 1 in the manuscript and Geographic_locations_Runemark_et_al.txtDorsal_headshape_RWs_Runemark_et_alRelative warps (RWs) reflecting dorsal head shape of individuals. These were obtained from the tpsRelw software. Population affinity of individuals is denoted by letter combinations as in Figure 1 in the manuscript and Geographic_locations_Runemark_et_al.txtBiteforce_headwidth_Runemark_et_alData on biteforce (unitless measure) in relation to head width for individuals from different populations. Population abbreviations are as in Figure 1 in the manuscript and Geographic_locations_Runemark_et_al.txtRealized_diet_composition_Runemark_et_alContains data on realized diet composition from fecal samples. Contains a table with the realized diet composition of the seven populations included in the study. The first column entitled 'population' includes the population abbreviations (D refers to Mesa Diavates; DII to Exo Diavates; L to Lakonisi; IA to Island of Atsitsa; AF to Agios Fokas; PA to Palamari; N to Nyfi) as illustrated in Figure 1 and given in Figure 3 in the manuscript, the second column denotes the habitat ('I' for islet or 'M' for mainland) and the third the sex of the individual. In the following columns we provide the 19 taxonomic prey categories and the number of each prey item found in the stomach of each individual.Available_diet_Runemark_et_alData on available diet. Taxonomic composition per pitfall trap. The localities are the same as the populations in Figure 1 in the paper and Geographic_locations_Runemark_et_al.txt