Spatial and temporal distribution of vertebrates in Libyan wetlands and their importance as stopover sites for migratory birds

Libyan wetlands are at a unique and important biogeographic spot between the Palearctic and Afrotropical ecozones, yet they are still one of the biggest gaps in Mediterranean biodiversity knowledge. This research presents the first extensive, multi-taxa evaluation of vertebrate distribution and abundance throughout a network of Libyan coastal and inland wetlands, aimed at assessing their functional significance as stopping places for migrating avifauna. We posited that the geographical distribution of vertebrate assemblages and the temporal abundance of migratory species are mostly influenced by wetland hydro-geomorphological features and the gradient of anthropogenic pressure. From 2022 to 2024, we conducted systematic surveys of birds, mammals, reptiles, amphibians, and fish at 15 important wetland locations. Our study found 142 vertebrate species in total, some of which are of importance for conservation throughout the world. Spatial analysis identified four wetlands as vital biodiversity hotspots, distinguished by elevated species richness and the occurrence of uncommon species. Time studies of avifauna showed clear seasonal peaks in abundance, with spring migration happening from late March to early May and fall migration from September to November. This confirmed their important role along the migratory flyways in the Central and Eastern Mediterranean. Multivariate models showed that wetland acreage, water salinity, and vegetation complexity were the most important environmental determinants of community composition. We created a Wetland Importance Index (WII) based on these results. The WII is a scientifically sound way to set conservation priorities. This study addresses a significant gap in knowledge by statistically demonstrating the essential function of Libyan wetlands within the broader Afro-Eurasian migratory system, while also providing a practical resource for national conservation planning and the strategic designation of future Ramsar sites.