A long-term photographic dataset for individual identification of the Balearic wall lizard

We present BalearicLizard , a curated, long-term collection of high-resolution photographs of the Balearic wall lizard (Podarcis lilfordi) designed to support non-invasive individual re-identification, ecological monitoring and computer-vision benchmarking. The dataset comprises 4,619 images from 1,009 individuals acquired during 15 years of systematic capture-recapture monitoring (from October 2010 to September 2024) on Illot d'en Curt, a small islet off the southern coast of Mallorca in the Balearic Islands, Spain. For each capture, we provide the original field photograph, a derived crop focusing on the ventral scale pattern, and standardised metadata including capture date, individual identifier and file location. Individual lizards were manually identified and curated by expert observers based on distinctive ventral scale arrangements, with historical mislabellings corrected using automated re-identification models. BalearicLizard offers a high-quality benchmark for developing and evaluating individual re-identification methods in small-bodied reptiles and a reusable resource for demographic and conservation studies of endemic island lizard populations. Data are released under CC BY 4.0 via Kaggle ( https://www.kaggle.com/datasets/roberalcaraz/baleariclizard ).