Rresearch On Migration Characteristics And Potential Habitat Of Common Cuckoo (Cuculus Canorus) Based On Satellite Tracking

Seasonal climate changes and fluctuations in food resources prompt migratory behavior in birds between breeding and wintering grounds.Studying the migratory characteristics and potential habitat distribution of migratory birds is crucial for their conservation.The common cuckoo(Cuculus canorus)is a long-distance migratory bird that flies alone at night and is widely distributed throughout Eurasia.The migratory characteristics of European breeding cuckoos have been reported,but more research is needed to elucidate the migratory patterns and strategies of the central breeding individuals of the subspecies when facing ecological barriers such as the Qinghai-Tibet Plateau.In this study,we captured and installed satellite trackers on cuckoos breeding at the same site within the Anxi extreme arid desert National Nature Reserve in Gansu Province.Through tracking data from 13 cuckoos,we analyzed the migratory patterns and strategies of central Asian breeding cuckoos.At the same time,we used MaxEnt models and cuckoo site data throughout the year to predict their current and future potential habitats,and compared the results of two time periods to explore how cuckoos adjust their potential habitats in response to global warming.Finally,we obtained the following results:(1)The central Asian breeding cuckoo is restricted by large ecological barriers such as the Qinghai-Tibet Plateau,oceans,and deserts.Its migratory route can be divided into two lines: the western line,which migrates southward along the western edge of the Qinghai-Tibet Plateau,and the eastern line,which migrates along the eastern and southern edges of the Qinghai-Tibet Plateau.There have also been attempts to migrate north-south across the Qinghai-Tibet Plateau,but whether this is a successful migratory route is currently unknown.(2)The central Asian breeding cuckoo adopts a circular migratory route and winters in Africa,but tends to migrate to the southeast part of Africa.Different migratory routes are taken in autumn and spring.The cuckoo shows a certain loyalty to stopover sites,as evidenced by its utilization of the same stopover site during two autumn migrations in 2019,and the use of similar stopover sites by different individuals.After completing the spring migration,the cuckoo did not choose to return to its original breeding site in 2019,which suggests that the cuckoo does not have a high degree of loyalty to its breeding site.The migratory direction of different individuals shows some variation.(3)Based on the results of independent t-tests,there were no significant differences in migration characteristics between different migration routes and genders.The speed of spring migration was 789.80±314.68 km/day,significantly higher than that of autumn migration at 548.61±340.37 km/day(P=0.005).The duration of stopovers during spring migration was 9.97±7.16 days,while that of autumn migration was 13.28±8.11 days.During spring migration,daily flight time was concentrated between 0-12 o’clock,while during autumn migration it was between 0-6 o’clock.The spring migration used a faster speed and longer flight time to return to the breeding grounds,while the autumn migration used a relatively slower migration speed and longer stopover duration to ensure safe passage through ecological barriers to reach the wintering grounds.The spring migration adopted a strategy of minimizing time,possibly to adapt to the egg-laying time of the host.The autumn migration adopted a strategy of minimizing energy consumption to ensure the success rate of migration.(4)Using the MaxEnt model to predict the potential habitat of the Great Bustard throughout the year,the results showed that the current potential habitat area of the Great Bustard in the climate model was 16,043,300 square kilometers,accounting for18% of the layer area.In the future climate model,the potential habitat area of the Great Bustard is estimated to be 18,735,900 square kilometers,accounting for 21% of the layer area.(5)In ArcGIS 10.6,the SDMtoolbox 2.4 was used to compare and analyze the potential habitat changes of the great reed warbler between two periods.The results showed that the expanded potential habitat area was 8916100km2,accounting for10% of the layer area,while the reduced potential habitat area was 5634600km2,accounting for 6% of the layer area.The expanded potential habitat was mainly in the stopover areas of the great reed warbler,while the reduced area was mainly concentrated in the wintering areas in southern Africa.