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Aim: Understanding connectivity between avian breeding and non‐breeding areas is essential to understand processes affecting threatened migrants throughout their annual cycle. We attempted to establish migratory connectivity and flyway structure of the IUCN vulnerable Swan Geese (Anser cygnoides) by combining citizen science species' distribution models (SDMs) and feather stable isotope analysis. Locations: Russia, Mongolia and China. Methods: We established migratory origins and movements of 46 Swan Geese from five wintering locations by integrating citizen science SDMs and feather stable hydrogen isotope (δ2H) measurements by linking feathers to precipitation isoscapes in a Bayesian probability framework. Results: We determined multiple summering origins among Swan Geese from the most important wintering location, Poyang Lake, Jiangxi Province, China. As predicted, we found no evidence for sex‐biased differences in δ2H measurements. Four geese tracked with GPS/GSM loggers all migrated to moulting areas, which confirmed the accuracy of our predictions from δ2H assignments. Differences between summering ranges inferred from historical and modern samples coincided with major wetland loss in northeastern China since the 1950s. Despite limited historical data, we contend that this supports the hypothesis that the summering range prior to 1950 was much wider than that of the current population. Main conclusions: This was the first Asian study to establish migratory origins of wintering Anatidae based on stable isotopes and citizen science SDMs. We advocate the wider combined application of SDMs, telemetry studies and stable isotopes to investigate effectively avian migratory connectivity, as the results from this study provided important contributions to the development of conservation measures for this threatened and declining species in East Asia. [ABSTRACT FROM AUTHOR]

Dispersal affects the spatial distribution and population structure of species. Dispersal is often male‐biased in mammals while female‐biased in birds, with the notable exception of the Anatidae. In this study, we tested genetic evidence for sex‐biased dispersal (SBD) in the Swan Goose Anser cygnoides, an Asian endemic and IUCN vulnerable species, which has been increasingly restricted to breeding on Mongolian steppe wetlands. We analyzed the genotypes of 278 Swan Geese samples from 14 locations at 14 microsatellite loci. Results from assignment indices, analysis of molecular variance, and five other population descriptors all failed to support significant SBD signals for the Swan Goose at the landscape level. Although overall results showed significantly high relatedness within colonies (suggesting high levels of philopatry in both sexes), local male genetic structure at the 1,050 km distance indicated greater dispersal distance for females from the eastern sector of the breeding range. Hence, local dispersal is likely scale‐dependent and female‐biased within the eastern breeding range. These findings are intriguing considering the prevailing expectation for there to be female fidelity in most goose species. We suggest that while behavior‐related traits may have facilitated the local genetic structure for the Swan Goose, several extrinsic factors, including the decreasing availability of the nesting sites and the severe fragmentation of breeding habitats, could have contributed to the absence of SBD at the landscape level. The long‐distance molt migration that is typical of goose species such as the Swan Goose may also have hampered our ability to detect SBD. Hence, we urge further genetic sampling from other areas in summer to extend our results, complemented by field observations to confirm our DNA analysis conclusions about sex‐specific dispersal patterns at different spatial scales in this species. [ABSTRACT FROM AUTHOR]

The article discusses increase in population of goose in Northern Hemisphere due to result of fitness consequences from shifts to improved winter feeding opportunities on agricultural land and mentions hunting regulation and provision of protected areas. Topics discussed include degradation of the associated food supply in the Yangtze River floodplain (YRF), impact of climate change on the habitat and feeding on agricultural habitat.

Sympatric Chinese-wintering Eastern Tundra Bean Geese (Anser fabalis serrirostris , ETBG) breed in two widely separated Arctic areas (Central Russian Arctic and Anadyr region); South Korean-wintering birds (Chaun-South Korea) breed in a third discrete area between these two. Such winter/summer segregation likely structures the population, potentially resulting in distinct migration patterns and habitat-use throughout the annual cycle. We tracked individuals using GPS-GSM transmitters from all three of these geographically discrete ETBG subpopulations to see whether this was the case, testing for differences in migration patterns, seasonal and diurnal habitat-use using remotely sensed land-cover mapping. Mean migration distance of Central Arctic-China and Chaun-South Korea individuals did not differ significantly, but Anadyr-China birds travelled 15–24% further (mean: 1140 ​km, P ​< ​0.001). Despite this, mean spring migration durations were longest among Central Arctic-China ETBG, significantly longer than Anadyr-China geese, due to significantly longer stopovers, which were significantly longer than Chaun-South Korea birds. Autumn migration duration of Central Arctic-China and Chaun-South Korea individuals was significantly shorter than in spring, with fewer, shorter stopovers. Lack of significant differences in migration and stopover duration or numbers of stopovers between spring and autumn among Anadyr-China ETBG confirms this is a plastic trait, differing between subpopulations responding to prevailing conditions. Migration patterns and habitat-use differed significantly between all three ETBG subpopulations, although all tended to use wetlands more at night and croplands more in daytime in winter, suggesting specific adaptations and responses to differing conditions encountered along their different migration routes. Although untestable, we speculate that differences in habitat-use may affect fitness levels and genetic exchange between subpopulations, but based on our observations, conclude clear differences in migration and foraging ecology between these elements of the same subspecies, even in winter sympatry. [ABSTRACT FROM AUTHOR]