Data and code from: Telomere length is determined by intrinsic factors and is shortened during drought years in <em>Gallotia galloti</em>

This repository contains the raw data and annotated R code associated with the study of relative telomere length (rTL) dynamics in the Western-Canaries Lizard (Gallotia galloti) across Tenerife, Canary Islands, Spain. The dataset comprises qPCR-derived relative telomere length measurements from lizard tissue samples (blood and tail tip) collected across multiple localities spanning an elevational gradient, sampled across several years (2017–2022). Raw Cq values from qPCR plates are included alongside derived rTL values calculated using the Pfaffl method, which accounts for plate-specific amplification efficiencies. Additional biological and environmental variables accompany each sample record, including sex, snout-vent length, morphotype, elevation, and microclimate data (relative humidity, wind speed, solar radiation, radiant sky temperature). The R code covers the full analytical pipeline: (1) calculation of relative telomere length from raw CT values and assessment of inter-plate repeatability via intraclass correlation coefficients; (2) principal component analysis to reduce correlated environmental variables; (3) generalised linear mixed-effects modelling (GLMM) using a Gamma distribution with year as a random effect; (4) multi-model inference via AICc-based dredging and model averaging to identify key predictors of rTL; (5) hierarchical variance partitioning; and (6) sensitivity analyses examining the influence of tissue type, locality, and morphotype on model outcomes.