Data used for analysis of head length

Data are from Gymnodactylus amarali individuals collected from field sites near the Serra da Mesa Reservoir in central Brazil. The following column headings are used. area: Each field site was either an island created by the filling of the reservoir or part of the adjacent mainland site: a unique identifier for each field site lizard: a unique identifier for each lizard captured as part of the study sex: male, female, or unknown snout.vent.length_mm: the snout-vent length of the individual lizard head.length_mm: the length of the head of the individual lizard