Abstract:

Objective: This study aims to rank the importance of stopover sites of Siberian cranes at different spatial scales, and identify conservation gaps and propose management recommendations, based on the analysis of migration strategy and distribution pattern of Siberian cranes in the past 20 years. Methods: Using the satellite tracking data of ten Siberian Cranes in 2016 and 2017, four types of stopover sites were divided based on the different stopping days. The rank of each staging area was evaluated synthetically with the weighted assignment. The conservation gaps were identified and migratory routes were mapped using the spatial analysis function of ArcGIS 10.2. Results: There was no significant difference in migration parameters between spring and fall season, such as migration distance, staging frequency, staying duration and migration legs. A total of 62 and 104 stopover sites were screened in spring and fall seasons, belonging to 23 and 27 staging units/areas of five staging regions, respectively. Of which, only nine and 13 important stopover sites were identified in spring and fall seasons, including the known stopover sites in Zhalong, Momoge and Xianghai National Nature Reserves(NNRs) and their surrounding areas in the western Songnen Plain, and the Yellow River Delta of the North China Plain. Tumuji NNR of the western Songnen Plain, and Wolong Lake Provincial Nature Reserve and the eastern Keerqin Sandy Land of Liao River Plain were newly recognized. Important, common and temporary stopover sites and resting sites were outside the existing protection system by 36.4%, 37.5%, 40.7% and 72.4%, respectively. In general, the western Songnen Plain is the most important staging areas both in spring and fall. In spring, the Liao River Plain is the second important and the Yellow River Delta is the third important. The two staging regions are in the opposite situation in fall. The stopover sites in the middle and lower reaches of the Yangtze River are more important in fall than those in spring, while those in Daxing'an Mountains are the opposite. Conclusion: The migration mode of Siberian Cranes is the energy minimization strategy. The migration route likes the number '8' shape, where western Songnen Plain and Liao River Plain are located in the narrow bottleneck. The crane adopts the facultative migration, using hopping strategy in a large proportion of potential refueling sites and skipping strategy in order to bypass a poor quality stopover site. In the past 20 years, the distribution of stopover sites in China experienced a remarkable change. Liao River Delta was not the important stopover site in recent years, while the eastern wetland of Keerqin Sandy Land in Western Liao River Plain is the newly discovered important staging region. To ensure migration safety and long-term survival of Siberian Cranes, it is suggested to strengthen the supervision of the important stopover sites in the surroundings of current protected areas using the existing management institutions. For the important staging sites with small and scattered wetland area, it is recommended to establish a conservation community, such as the eastern wetland of Keerqin Sandy Land. The interdepartmental and interregional joint protection and management mechanism is proposed for temporary stopover sites and resting sites in North China Plain, and the middle and lower reaches of Yangtze River.

Key words: Siberian Crane, migration pattern, migration strategy, stopover sites, conservation gap