Contrasting habitat use and conservation status of Chinese-wintering and other Eurasian Greater White-fronted Goose (Anser albifrons) populations

Abstract

Background GPS/GSM tracking data were used to contrast use of (i) habitats and (ii) protected areas between three Arctic-nesting Greater White-fronted Geese (Anser albifrons, GWFG) populations throughout the annual cycle. We wished to demonstrate that the East Asian Continental Population (which winters on natural wetlands in the Chinese Yangtze River floodplain and is currently declining) avoids using farmland at multiple wintering sites. We also gathered tracking evidence to support general observations from two increasing population of GWFG, the North Sea-Baltic (which winters in Europe) and the West Pacific (which winter in Korea and Japan) winter mostly within farmland landscapes, using wetlands only for safe night roosts. Methods We tracked 156 GWFG throughout their annual cycle using GPS/GSM transmitters from these three populations to determine migration routes and stopover staging patterns. We used Brownian Bridge Movement Models to generate summer, winter and migration stopover home ranges which we then overlaid in GIS with land cover and protected area boundary at national level to determine habitat use and degree of protection from nature conservation designated areas. Results Data confirmed that 73% of European wintering GWFG homes ranges were from within farmland, compared to 59% in Japan and Korea, but just 5% in China, confirming the heavy winter use of agricultural landscapes by GWFG away from China, and avoidance of farmland at multiple sites within the Yangtze River floodplain. The same GWFG used farmland in northeast China in spring and autumn, confirming their experience of exploiting such habitats at other stages of their annual cycle. Chinese wintering birds showed the greatest overlap with protected areas of all three populations, showing current levels of site safeguard are failing to protect this population. Conclusions Results confirm the need for strategic planning to protect the East Asian Continental GWFG population. While the site protection network in place to protect the species seems adequate, it has failed to stop the declines. Buffalo grazing could serve as one simple strategy to improve the condition of feeding habitats at Dongting Lake and Poyang Lake in the Yangtze, where vast Carex meadows exist. In addition, while we warn against pushing GWFG to winter farmland feeding in China because of the long-term potential to conflict with agricultural interests, we recommend experimental sacrificial, disturbance-free farmland within designated refuge areas adjacent to the Yangtze River floodplain wetland reserves as a manipulative experiment to improve the conservation status of this population in years when natural food sources are limited.

The cascading effects of submerged macrophyte collapse on geese at Poyang Lake, China

“…Moreover, our study emphasises that food shortage may not only influence fitness of consumers through diet and foraging habitat shifts, but may also affect fitness of other animals through modification of interspecific interactions. Given the increasing important role of Poyang Lake in waterbird protection in the Yangtze River floodplain (Wang et al, 2017; Zhang et al, 2011) and the East Asian–Australasian Flyway (Damba et al, 2020; Deng et al, 2020; Li, Zhao, et al, 2020), it is urgent to reverse the broad decline of submerged macrophytes to protect waterbirds. Our study also emphasises the importance of behavioural plasticity for animals to cope with interspecific competition to respond rapidly to environmental changes.…”

Biogeographical variation in migratory patterns of palearctic breeding Greater White‐fronted Geese

“…Likewise, we defined autumn migration on similar criteria for the return to the wintering areas (Deng et al., 2019; Zhang et al., 2020). Failed breeders from BNS and WP populations undertook long‐distance moult migrations in summer, so autumn migration initiation was defined from moulting areas (either remote away from, or at breeding sites) to wintering areas (Deng et al., 2021; Kölzsch et al., 2019).…”

“…Failed breeders from BNS and WP populations undertook long-distance moult migrations in summer, so autumn migration initiation was defined from moulting areas (either remote away from, or at breeding sites) to wintering areas (Deng et al, 2021;Kölzsch et al, 2019).…”

“…Here, the regular shallow flooding of floodplain meadows in a natural river valley has always been important for spring staging GWFG, but here, as elsewhere in Western Europe, geese have also benefitted from the movement to more abundant and profitable feeding opportunities associated with arable land (Polakowski et al, 2023). BNS geese therefore benefit from historically abundant staging sites, subject to recent improvements in profitability, due to agricultural development, using farmland far more than WP and especially EAC GWFG (Deng et al, 2021). In contrast, the degradation of stopover quality would deny eastern GWFG of spring staging foraging habitat, reducing the functional integrity of their migration stopover networks and the migration connectivity of staging sites, ultimately contributing to mortality on migration (Xu et al, 2020).…”

Using Tracking Data to Identify Gaps in Knowledge and Conservation of the Critically Endangered Siberian Crane (Leucogeranus leucogeranus)

“…Ironically, site protection for such species may be very good in breeding and wintering areas, where waterbirds may aggregate in large numbers for prolonged periods (i.e., several months). In contrast, site safeguarding is often lacking or, at best, uneven between jurisdictions for sites where birds may stage [2,3], despite the fact that these locations may be crucial for individuals to obtain the nutrients and energy necessary for the completion of their migratory episode and the next phase in their annual cycle. Far too often, such staging areas are remote, hard to access, or simply unknown, making it difficult to establish their relative importance within the context of a species' annual cycle.…”