Reptile assemblages in eastern Mediterranean maquis are shaped by climate, land management, habitat structure and a novel threat of egret predation

Abstract

Mediterranean landscapes have been shaped by millennia of human activities, but recent land use changes resulted in the loss of open habitats and the introduction of a novel predator, the cattle egret (Bublucus ibis). These processes may specifically affect reptiles, so we investigated their impacts on reptile communities in 272 maquis in Northern Israel. We collected data on climate, land use, land cover, and potential egret predation pressure, and modelled their effects on reptile species abundance, richness, and turnover. Reptile abundance increased in colder, wetter and higher sites whereas species richness peaked in sites with intermediate geoclimatic conditions. Both abundance and richness were positively associated with goat grazing. Reptile species known to be preyed upon by egrets exhibited lower abundance at sites with high egret predation pressure. Total reptile abundance, egret-prey abundance, and reptile richness tended to be higher in sites with intermediate cover of woody vegetation. Species turnover was weakly related to variation in climate and habitat variables. In sum, maquis reptile assemblages are shaped by an interplay of climate, land use, habitat structure, and predation risk. Consequently, climate warming may lead to abundance declines in drier sites and some reptile habitats are deteriorating in the absence of goat grazing. Alarmingly, a novel threat manifested by the expansion of cattle egrets can have adverse effects on the abundance of egret-sensitive species. Collectively, these processes highlight reptile communities as an emerging conservation concern in maquis ecosystems exposed to land use and climate change, specifically where cattle egrets are prevalent.