- H. Kruckenberg (1)
- A. Kölzsch (1)
- S. Moonen (1)
- G.J.D.M. Müskens (1)
- B.A. Nolet (1)
- Yali Si (1)
- P. Szinai (1)
- M. Wikelski (1)
- Yanjie Xu (1)
- Shenglai Yin (1)
- Wenyuan Zhang (1)
Flyway connectivity and exchange primarily driven by moult migration in geese
Kölzsch, A. ; Müskens, G.J.D.M. ; Szinai, P. ; Moonen, S. ; Glazov, P. ; Kruckenberg, H. ; Wikelski, M. ; Nolet, B.A. - \ 2019
Movement Ecology 7 (2019)1. - ISSN 2051-3933
Dynamic Brownian bridges - GPS tracking - Greater white-fronted goose - Long-distance moult migration - Migratory connectivity - Population exchange - Population overlap - Taimyr peninsula
Background: For the conservation and management of migratory species that strongly decrease or increase due to anthropological impacts, a clear delineation of populations and quantification of possible mixing (migratory connectivity) is crucial. Usually, population exchange in migratory species is only studied in breeding or wintering sites, but we considered the whole annual cycle in order to determine important stages and sites for population mixing in an Arctic migrant. Methods: We used 91 high resolution GPS tracks of Western Palearctic greater white-fronted geese (Anser A. albifrons) from the North Sea and Pannonic populations to extract details of where and when populations overlapped and exchange was possible. Overlap areas were calculated as dynamic Brownian bridges of stopover, nest and moulting sites. Results: Utilisation areas of the two populations overlapped only somewhat during spring and autumn migration stopovers, but much during moult. During this stage, non-breeders and failed breeders of the North Sea population intermixed with geese from the Pannonic population in the Pyasina delta on Taimyr peninsula. The timing of use of overlap areas was highly consistent between populations, making exchange possible. Two of our tracked geese switched from the North Sea population flyway to the Pannonic flyway during moult on Taimyr peninsula or early during the subsequent autumn migration. Because we could follow one of them during the next year, where it stayed in the Pannonic flyway, we suggest that the exchange was long-term or permanent. Conclusions: We have identified long-distance moult migration of failed or non-breeders as a key phenomenon creating overlap between two flyway populations of geese. This supports the notion of previously suggested population exchange and migratory connectivity, but outside of classically suggested wintering or breeding sites. Our results call for consideration of moult migration and population exchange in conservation and management of our greater white-fronted geese as well as other waterfowl populations.
Species-dependent effects of habitat degradation in relation to seasonal distribution of migratory waterfowl in the East Asian–Australasian Flyway
Xu, Yanjie ; Si, Yali ; Yin, Shenglai ; Zhang, Wenyuan ; Grishchenko, Mikhail ; Prins, Herbert H.T. ; Gong, Peng ; Boer, Willem F. de - \ 2019
Landscape Ecology 34 (2019)2. - ISSN 0921-2973 - p. 243 - 257.
East Asian–Australasian Flyway - Fragmentation - Habitat loss - Isolation - Migratory connectivity - Migratory waterfowl - Seasonal distribution - Species trait - Wetland
Context: Migratory species’ resilience to landscape changes depends on spatial patterns of habitat degradation in relation to their migratory movements, such as the distance between breeding and non-breeding areas, and the location and width of migration corridors. Objectives: We investigated to what extent the impact of habitat degradation depended on the seasonal distributions of migratory waterfowl. Methods: Using logistic regression, we selected wetland sites for eight waterfowl species in the East Asian–Australasian Flyway (EAAF) by calculating the probabilities of species occurrence per wetland site in relation to environmental factors. We quantified landscape metrics related to habitat degradation within these wetland sites. We used general linear models to test for differences in the effects of habitat degradation on waterfowl species with different migration extents and at different latitudes. Results: The patterns of habitat degradation differed spatially across the EAAF and affected species to a different degree. Species with shorter and broader migration corridors (Anser cygnoid and A. anser) could benefit from improved habitat conditions in the west of the EAAF. Species with longer and narrower migration corridors (Cygnus columbianus, A. fabalis, A. albifrons, A. erythropus, Anas crecca, and Anas acuta) were under higher risk of habitat degradation in the coastal regions of China and Japan. Conclusions: Migratory species with longer and narrower migration corridors are more affected by habitat degradation, because they might have fewer alternative stopover sites at similar latitude. Our findings improve the understanding of species-specific effects of environmental changes on migratory species, and defines critical and endangered wetland sites, and vulnerable species.