Geophagy in alien leporids: evidence from sympatric rabbits and cottontails

Geophagy is widespread among vertebrates but remains poorly documented in lagomorphs. Here, we provide the first evidence of soil ingestion in wild European rabbits Oryctolagus cuniculus and invasive Eastern cottontails Sylvilagus floridanus, based on camera-trap observations from a peri-urban reserve in northern Italy. Both species were recorded ingesting soil at the entrance of an active rabbit warren and on the adjacent excavation mound. Soil analyses indicated that the mound differed chemically from nearby control samples, consistent with exposure of deeper soil horizons through burrowing. Given the predominantly sandy texture of the soil, the detoxification via clay-mediated adsorption appears unlikely, while sodium supplementation emerges as a more plausible driver. We propose that rabbit excavation may create microhabitats that facilitate soil access for both leporids, potentially influencing their interactions. These observations reveal an overlooked behavioural dimension in lagomorphs and highlight the need for integrative studies on the nutritional and ecological significance of geophagy in this guild.