Abstract:

Aims: As one of the most important pastures in China, the Qilian Mountains is covered with fences. Fence serve as a valuable tool to manage and protect wildlife. However, these also lead to the death of countless animals. Due to the Qilian Mountains being an area with high biodiversity, the fences in this area could cause a significant impact on wildlife, including black-necked cranes (Grus nigricollis). In order to better understand the influence of fences, at the southern foothills of Qilian Mountains, on the black-necked crane, a new study must be implemented that seeks to provide scientific evidence that can be used for evaluating the fence system throughout Qilian Mountains.

Methods: From 2020 to 2021, our team installed a satellite transmitter on juvenile, black-necked cranes in the southern foothills of the Qilian Mountains. These allowed for the remote monitoring of juveniles, which allowed to determine any abnormal changes in activity. If a carcass was found, cause of death was determined. The post-fledging period and the fully-fledged period of black-necked crane are confirmed by time-series clustering. Kernel density estimation (KDE) and minimum convex polygon (MCP) were used to estimate home range and core area in fence habitats and non-fenced habitats. Mann-Whitney U test was used to test the difference between fence habitat and non-fenced habitat during the post-fledging period and the fully-fledged period.

Results: The mortality rate of black-necked crane juveniles on the southern foothills of Qilian Mountains was 26.67% in 2020 and 20.00% in 2021. Among them, 50% of the deaths were caused by fences, with most deaths occurring near the Luanhaizi Wetland. The fence will not only cause injury or death to juvenile black-necked cranes but also significantly restrict the home range and core area of black-necked cranes during the post-fledging period. However, this restriction will be greatly reduced in the fully-fledged period.

Conclusion: In order to reduce the impact of fence on black-necked crane, we suggest changing the type of fence used, with no inclusion of barbed wire. Furthermore, old fences should be removed when new fences are installed, and maintenance on these should be performed regularly. Lastly, the marking of fences should be considered in order to reduce collisions between these and black-necked cranes. This could result in the improvement of wildlife habitat in the southern foothills of Qilian Mountains.

Key words: black-necked crane, fence, Qilian Mountains, mortality rate, home range