Most migratory birds depend on stopover sites, which are essential for refueling during migration and affect their population dynamics. In the East Asian–Australasian Flyway (EAAF), however, the stopover ecology of migratory waterfowl is severely under-studied. The knowledge gaps regarding the timing, intensity and duration of stopover site usages prevent the development of effective and full annual cycle conservation strategies for migratory waterfowl in EAAF. In this study, we obtained a total of 33,493 relocations and visualized 33 completed spring migratory paths of five geese species using satellite tracking devices. We delineated 2,192,823 ha as the key stopover sites along the migration routes and found that croplands were the largest land use type within the stopover sites, followed by wetlands and natural grasslands (62.94%, 17.86% and 15.48% respectively). We further identified the conservation gaps by overlapping the stopover sites with the World Database on Protected Areas (PA). The results showed that only 15.63% (or 342,757 ha) of the stopover sites are covered by the current PA network. Our findings fulfil some key knowledge gaps for the conservation of the migratory waterbirds along the EAAF, thus enabling an integrative conservation strategy for migratory water birds in the flyway.

In the last 15 years, the west population of white-naped crane (Antigone vipio) decreased dramatically despite the enhanced conservation actions in both breeding and wintering areas. Recent studies highlighted the importance of protecting the integrity of movement connectivity for migratory birds. Widespread and rapid landcover changes may exceed the adaptive capacity of migrants, leading to the collapse of migratory networks. In this study, using satellite tracking data, we modeled and characterized the migration routes of the white-naped crane at three spatial levels (core area, migratory corridor, and migratory path) based on the utilization distribution for two eras (1990s and 2010s) spanning 20 years. Our analysis demonstrated that the white-naped crane shifted its migratory route, which is supported by other lines of evidences. The widespread loss of wetlands, especially within the stopover sites, might have caused this behavioral adaptation. Moreover, our analysis indicated that the long-term sustainability of the new route is untested and likely to be questionable. Therefore, directing conservation effects to the new route might be insufficient for the long-term wellbeing of this threatened crane and large-scale wetland restorations in Bohai Bay, a critical stopover site in the East Asian-Australasian flyway, are of the utmost importance to the conservation of this species.

The continuous increase in the number of reservoirs globally has raised important questions about the environmental impact of their greenhouse gases emissions. In particular, the littoral zone may be a hotspot for production of greenhouse gases. We investigated the spatiotemporal variation of CO₂ flux at the littoral zone of a Chinese reservoir along a wet-to-dry transect from permanently flooded land, seasonally flooded land to non-flooded dry land, using the static dark chamber technique. The mean total CO₂ emission was 346 mg m⁻² h⁻¹ and the rate varied significantly by water levels, months and time of day. The spatiotemporal variation of flux was highly correlated with biomass, temperature and water level. Flooding could play a positive role in carbon balance if water recession occurs at the time when carbon gains associated with plant growth overcomes the carbon loss of ecosystem. The overall carbon balance was analysed using cumulative greenhouse gases fluxes and biomass, bringing the data of the present study alongside previously published, simultaneously measured CH₄ and N₂O fluxes. For the growing season, 12.8 g C m⁻² was absorbed by the littoral zone. Taking CH₄ and N₂O into the calculation showed that permanently flooded sites were a source of greenhouse gases, rather than a sink. Our study emphasises how water level fluctuation influenced CO₂, CH₄ and N₂O in different ways, which greatly affected the spatiotemporal variation and emission rate of greenhouse gases from the littoral zone.

The middle and lower reaches of the Yangtze River are the most important areas for geese to overwinter in the East Asian–Australasian Flyway, where about 180,000 geese fly to overwinter each year. Over the past 20 years, the region has experienced extensive and rapid land cover changes that may have exceeded the adaptability of geese, and have led to suitable goose habitat area loss, thereby, reducing the stability of the geese population. In order to identify the suitable goose habitat areas in this region, based on ensemble modeling and satellite tracking data, in this study, we simulated the spatial distribution changes in the suitable goose habitat areas over the past 20 years. The results showed that the suitable goose habitat areas had suffered varying degrees of loss, among which, the lesser white-fronted goose had the greatest suitable goose habitat area loss of over 50%. Moreover, we found that wetlands, lakes, and floodplains were the key components of suitable goose habitat areas, and the categories (land use) showed significant differences in different periods (p < 0.01). This may be one of the main reasons for the decrease in suitable goose habitat areas. The results of this study provide an important reference for the adaptive management and protection of geese in the middle and lower reaches of the Yangtze River.

Global climate change has significantly impacted waterbird communities in the warming and humidifying wetlands of the Qinghai–Tibet Plateau. However, further research is needed as these wetlands transition to warmer and drier states. This study focused on the diversity and richness of wintering birds in the alpine wetlands of the Yamzho Yumco Lake. By analyzing data collected from 17 sampling sites over seven years, we examined the abundance changes of waterbirds in the lake and surrounding land and determined the relationship between the structure of waterbird communities and climate data. The results have shown that the abundance, richness, and α-diversity index of wintering waterbirds fluctuated. Wintering waterbirds were positively correlated with monthly mean temperature and monthly mean higher temperature and negatively correlated with monthly total precipitation and water level. Principal component analysis (PCA) showed that temperature contributed the most to the wintering waterbirds. Bird abundance and diversity in the drying wetlands of Yamzho Yumco Lake showed the same results. As temperatures continue to increase and precipitation decreases, the number of wintering waterbirds may also increase. We have highlighted the indicative role of Yamzho Yumco Lake in climate change responses from warming and humidification to warming and aridification and suggest that decision makers strengthen monitoring of the Yamzho Yumco Lake Reserve, restrict human activities, improve water resource management, and actively respond to the challenges brought about by climate change.

Accurate species distribution modelling is essential for conservation planning, particularly for river-dependent species whose habitats are poorly captured by conventional distance-based predictors. The endangered Scaly-sided Merganser (Mergus squamatus) relies on linear freshwater habitats during winter, yet riverine habitat structure is often oversimplified in broad-scale species distribution models. Here, we developed a multi-algorithm modelling framework to map wintering habitat suitability for the species in the Dongting Lake Basin, China. Occurrence records were compiled primarily from systematic surveys and spatially thinned to reduce sampling bias. We compared MaxEnt, random forest, generalized additive models, and boosted regression trees under five-fold spatial block cross-validation, and generated an ensemble prediction across algorithms. The final predictor set emphasized hydrological and topographic attributes, including maximum water width, reservoir capacity, density of the river network, valley depth, landform type, and channel-network base level. Predictor importance and response curves indicated that wintering habitat suitability was shaped mainly by open-water scale, terrain position, valley structure, and regulated water storage. The ensemble prediction identified priority high-suitability areas mainly along the middle and lower Yuan River and the upper Xiang River, with smaller local patches along the Li and Zi Rivers and selected reservoir systems. These findings suggest that hydrological and topographic predictors can enhance the ecological representation of river-dependent waterbird habitats in SDMs and provide spatial evidence for targeted river-reach conservation.