Biodiv Sci ›› 2022, Vol. 30 ›› Issue (5): 21232.  DOI: 10.17520/biods.2021232

• Original Papers: Animal Diversity • Previous Articles     Next Articles

Migration strategy of the Bohai Bay wintering population of juvenile Oriental Storks (Ciconia boyciana)

Garidi1,2, Shujuan Fan4, Lei Cao2, Beixi Zhang3, Yuxi Wang4, Baoguang Zhu5, Shubin Dong5, Anton Sasin6, Gerelt Zhao1,*()   

  1. 1 College of Life Science and Technology, Inner Mongolia Normal University, Hohhot 010020, China
    2 State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
    3 University of Chinese Academy of Sciences, Beijing 100049, China
    4 University of Science and Technology of China, Hefei 230026, China
    5 Heilongjiang Honghe National Nature Reserve Administration, Jiamusi, Heilongjiang 156332, China
    6 Far Eastern State Agrarian University, Blagoveshchensk 675000, Russia
  • Received:2021-06-07 Accepted:2022-03-06 Online:2022-05-20 Published:2022-05-20
  • Contact: Gerelt Zhao

Abstract:

Aims: The Oriental Stork (Ciconia boyciana) primarily breeds in the Far East of Russia and Northeast China. There are two main migratory populations wintering in China, the Yangtze River wintering population, with a migration distance of about 2,600 km, and the Bohai Bay wintering population, with a migration distance of about 1,500 km. This study was conducted to obtain the characteristics of migration strategies and wind utilization of wintering populations in Bohai Bay during spring and autumn migration.

Methods: Based on the satellite tracking data of 14 juveniles from 2016 to 2018, we compared differences in their autumn and spring migration patterns and studied the effects of wind speed and direction at 850 mb on migration speed of the Bohai Bay wintering population.

Results: The migration distances in spring and autumn were similar, and the tailwind conditions in spring (2.2 ± 6.3 m/s) were significantly better than that in autumn (-2.4 ± 4.1 m/s, P < 0.05), leading to the daily flying speed in spring (280.4 ± 62.0 km/d) being significantly faster than that in autumn (185.5 ± 72.0 km/d, P < 0.05), and the flight duration of the spring migration (5.9 ± 2.9 d) was significantly shorter than that of the autumn migration (10.3 ± 6.5 d). Furthermore, the stopover time in spring (5.4 ± 9.7 d) was significantly shorter than that in autumn (17.8 ± 18.2 d, P = 0.05). Based on the above two points, the migration duration in spring (11.2 ± 8.7 d) was significantly shorter than that in autumn (28.0 ± 21.2 d, P < 0.05).

Conclusion: When migrating from/to Bohai Bay, the 14 juveniles used tailwinds to reach summering grounds faster in spring, and when they migrated headwinds in autumn, they flied slower and had longer flight and rest times. In conclusion, the Oriental Stork is a migratory soaring bird that primarily relies on thermal flow, while the tailwind also contributes to the migration success.

Key words: Ciconia boyciana, GPS/GSM tracking, migration strategy, tailwind, migration duration, daily flying speed