Nota su un’inusuale aggregazione tardo-autunnale di Podarcis muralis in un ambiente urbanizzato

The common wall lizard is the most widespread reptile in northern Italy. It occurs in both natural habitats and heavily urbanized areas, including the historic centers of large cities, where it is often the only reptile species present. Under favorable conditions: availability of refuges, good sun exposure, and adequate vegetation cover it can reach very high population densities. On 5th November 2025, 41 individuals of Podarcis muralis were recorded in a flowerbed located in front of the Town Hall of Pavia, most of them observed along the stone edging that borders the area. The flowerbed is of moderate size (383 m²) and is surrounded by roads and buildings unsuitable for P. muralis. Its vegetation consists of permanent mowed lawn bordered by Iris pallida, Nepeta racemosa, and Oenothera lindheimeri, along with two Cornus florida and one Olea europaea. The individuals observed represent only a minimum estimate of the population, as likely only a fraction of the lizards was active and visible at that given time. Even so, the “minimum density” calculated from the counted individuals corresponds to 1070 ind/ha, a value comparable to one of the highest densities reported for the species in the literature: 1133 ind/ha (calculated using the Bailey estimator) in a cemetery in southwestern France. This record documents a possible case of late-autumn aggregation in a particularly favorable urban microhabitat and suggests that even small green areas, when structurally suitable, can sustain very dense populations of P. muralis.