Could bats be a good tool for monitoring highly fragmented and endangered forest habitats?

Habitat fragmentation poses a major threat to forest biodiversity, particularly in spatially restricted and endangered ecosystems. Identifying reliable indicators capable of reflecting fragmentation effects remains a key challenge for conservation-oriented forest monitoring. Bats are frequently proposed as bioindicators due to their sensitivity to habitat structure and prey availability; however, empirical evidence supporting their indicator value is often context-dependent and methodologically constrained. In this study, we evaluated the potential of bats as indicators of habitat fragmentation in the Eastern Mediterranean / Oriental Sweetgum (Liquidambar orientalis) forests, a highly threatened and naturally fragmented forest ecosystem with a very limited global distribution. Fieldwork was conducted in the Köyceğiz–Dalyan Specially Protected Area (southwestern Türkiye) between November 2022 and May 2023. Ten forest patches (30–250 ha) were classified into four categories based on patch size and fragmentation level. A total of 47 bat boxes were monitored biweekly, and bats using these boxes were captured, measured, and ringed to assess individual roost use across different fragmentation contexts. In total, 39 individuals belonging to four Pipistrellus species were recorded, all during the wintering period. Ringed individuals were unevenly distributed among fragmentation categories; however, statistical analysis (one-way ANOVA) did not detect a significant effect of fragmentation level on bat box selection. Although no clear fragmentation signal was detected, the limited monitoring duration, low recapture rates, and unbalanced sample sizes constrain statistical power. Consequently, conclusions regarding the use of bats as indicators of forest fragmentation in this system should be regarded as preliminary and hypothesis-generating rather than definitive. Despite these limitations, this study represents the first ringing-based bat monitoring effort in Oriental Sweetgum forests and provides a critical baseline for future long-term, multi-method monitoring. Extended temporal datasets integrating ringing, acoustic monitoring, and fine-scale fragmentation metrics will be essential to clarify bat responses to fragmentation and to inform conservation strategies for this endangered forest ecosystem.