Impacts of prolonged dry season and artificial food supply on the wintering spatial distribution of Siberian Cranes:
Implications for conservation
Abstract
Poyang Lake, China’s largest freshwater lake, is a critical wintering ground for most of the global Siberian Crane (Grus leucogeranus) population. However, increasingly prolonged dry seasons have degraded the natural wetlands of Poyang Lake, forcing Siberian Cranes to shift to artificial habitats. From 2015 to 2023, field surveys revealed a substantial increase in the number of Siberian Cranes in artificial habitats, with peak counts reaching 3000 individuals, accounting for up to 53% of the species’ global population. Satellite telemetry of 13 individuals further confirmed the spatial use of these habitats, highlighting their consistent reliance on artificial sites over multiple years. Seven high-use hotspots were identified outside of Poyang Lake, including two artificial provisioning sites that supported dense foraging flocks for extended periods. Satellite telemetry confirmed this trend, with artificial habitats making up to 64.2% of the occurrence sites in some years. This reliance on artificial habitats was closely linked to the reduced tuber biomass in natural wetlands and low winter water levels in Poyang Lake, which collectively explained 83% of the variance in crane abundance in artificial habitats. Artificial habitat use peaked in December and January, indicating marked seasonal variation. Siberian Cranes also exhibited a pronounced circadian rhythm, foraging in artificial habitats during the day and returning to natural wetlands to roost at night. Despite the shift toward artificial habitats, natural wetlands remain critical for nighttime refuge. The continued dependence on artificial habitats raises concerns about disease transmission owing to dense congregations. Conservation strategies should prioritize both the careful management of artificial provisioning sites and the restoration of natural wetlands to improve food and habitat availability within natural ecosystems, ultimately enabling the return of Siberian Cranes to their traditional natural habitats.
点击查看PDF文件
