Spring migration duration exceeds that of autumn migration in Far East Asian Greater White-fronted Geese (Anser albifrons)

Abstract

Background: Migration theory suggests, and some empirical studies show, that in order to compete for the best breeding sites and increase reproductive success, long-distance avian migrants tend to adopt a time minimization strategy during spring migration, resulting in shorter duration spring migration compared to that in autumn. Methods: Using GPS/GSM transmitters, we tracked the full migrations of 11 Greater White-fronted Geese (Anser albifrons) between southeast China and the Russian Arctic, to reveal the migration timing and routes of the East Asian population, and compare the difference in duration between spring and autumn migration of this population. Results: We found that migration in spring (79 ± 12 days) took more than twice as long to cover the same distance as in autumn (35 ± 7 days). This difference in migration duration was mainly determined by significantly more time spent in spring (59 ± 16 days) than in autumn (23 ± 6 days) at significantly more stopover sites. Conclusions: We suggest that these geese, thought to be partial capital breeders, spent almost three quarters of total migration time at spring stopover sites to acquire energy stores for ultimate investment in reproduction, although we cannot reject the hypothesis that timing of the spring thaw also contributed to stopover duration. In autumn, they acquired necessary energy stores on the breeding grounds sufficient to reach Northeast China staging areas almost without stop, which reduced stopover times in autumn and resulted in the faster autumn migration than spring.

Combining Tracking and Remote Sensing to Identify Critical Year-Round Site, Habitat Use and Migratory Connectivity of a Threatened Waterbird Species

“…We calculated great-circle-distances, using the "haversine method" [18], between adjacent GPS locations using the distHavesine function in the geosphere package [19] in R (R Development Core Team 2017). We used the methods described in previous studies [20][21][22][23] to analyse crane movements, differentiating sections of the tracking paths into periods of migration between stopover/staging, breeding or wintering areas, where tracked individuals would still diurnally commute between feeding and roosting areas, but not undertake long, largely unidirectional movement (for further details see Appendix S1 in Supplementary Materials). Based on these segmentations and classifications, we defined 11 migration parameters to describe the specific cranes' movement patterns and features of migration (Table 1) from the birds for which we derived full information over an entire migration episode (i.e., birds for which continuous movement data were available from summer to wintering grounds or vice versa).…”

Lessons learned and questions raised during and post-COVID-19 anthropopause period in relation to the environment and climate

“…Particularly in China, a total of 53.6 million hectares of wetlands such as lakes, swamps, rivers as well as artificial wetlands provide breeding and wintering sites for several species including cranes, gulls, ducks, and geese (Wang et al 2018 ). A recent study (Deng et al 2019 ) shows that the Greater White-fronted Geese autumn migration starts from the Russian Arctic breeding sites in late September moving to wintering areas in southeast China in late October. These worldwide migrating pathways provide a possible natural avian carrier network which should be considered seriously in any mechanism explaining interspecies transmission of viruses.…”

Occurrence of Mycoplasma spp. in wild birds: phylogenetic analysis and potential factors affecting distribution

“…The white-fronted goose is a migratory bird of which the breeding grounds cover almost the whole circumpolar Arctic 77 . However, these birds choose various wintering destinations such as eastern Asia 78 or western Europe 79 . They make many stopovers during migration, which increases the risk of contamination of domestic goose water and pastures by their feces.…”