Water sources shape drought effects on mammal activity in mediterranean woodlands

Abstract

Drought frequency and severity have notably increased in the Mediterranean basin throughout the 20th century, thereby impacting freshwater sources and forest regrowth, which are crucial for woodland mammal survival. We used camera trapping data collected from a mountain range in NE Spain from 2018 to 2023 (coinciding with an extreme drought event) to test whether freshwater sources, such as ponds and springs, act as biodiversity refuges for woodland mammals during extreme drought. Meteorological conditions during the study, such as accumulated precipitation, air temperature anomalies, air humidity and Standardised Precipitation-Evapotranspiration Index (SPEI), were used to predict mammal activity, richness and diversity using linear mixed-effect models. We detected eight common species including wild boar (Sus scrofa, 48% of all detections), roe deer (Capreolus capreolus, 28%) and red fox (Vulpes vulpes, 10%). Contrary to our expectation, mammal activity was unaffected by the presence of freshwater sources. Our findings show that the presence of freshwater sources did not generally alleviate negative effects of drought on animal activity and diversity. These results may emerge because traditionally permanent freshwater sources in Mediterranean ecosystems (such as springs and ponds) have dried up during the extreme 2021–2023 drought, halting its function as biodiversity refugia for woodland mammals. Our results highlight the impact of extreme weather conditions on mammal activity and will help managers create more effective conservation strategies for mammals under increasingly dry conditions.