Ecological Correlates of 20-Year Population Trends of Wintering Waterbirds in Deep Bay, South China

Abstract

Along the East Asian-Australasian flyway (EAAF), waterbirds are threatened by a wide range of human activities. Studies have shown that wintering populations of many species have declined in Australia and Japan; however, long term data along China’s coast are limited. In this study, we analyzed data collected from monthly bird surveys to quantify population trends of wintering waterbirds from 1998 to 2017 in the Deep Bay area, South China. Of the 42 species studied, 12 declined, while nine increased significantly. Phylogenetic comparative analysis revealed that population trends were negatively correlated to reliance on the Yellow Sea and body size. Further, waterbird species breeding in Southern Siberia declined more than those breeding in East Asia. These findings, coupled with a relatively high number of increasing species, support the continual preservation of wetlands in the Deep Bay area. This study provides another case study showing that data collected from wintering sites provide insights on the threats along migratory pathway and inform conservation actions. As such, we encourage population surveys in the EAAF to continue, particularly along the coast of China.

Current breeding distributions and predicted range shifts under climate change in two subspecies of Black‐tailed Godwits in Asia

“…These factors might partially explain the decline of wintering waterbirds breeding in Siberia compared to temperate Asia (Sung et al, 2021). Our results highlight the importance of thinking ahead and factoring in shifts in bird distribution when designing climateproof conservation strategies to salvage our heritage of migratory birds and, ultimately, the ecosystems we all belong to.…”

“…drought and wildfires, see Kharuk et al, 2021, Yasunari et al, 2021) while experiencing both higher predation rates and increased competition for breeding space as more species and populations become concentrated in the Arctic rim (Killengreen et al, 2007; Layton‐Matthews et al, 2020; Vallejos et al, 2020). These factors might partially explain the decline of wintering waterbirds breeding in Siberia compared to temperate Asia (Sung et al, 2021). Our results highlight the importance of thinking ahead and factoring in shifts in bird distribution when designing climate‐proof conservation strategies to salvage our heritage of migratory birds and, ultimately, the ecosystems we all belong to.…”

“…In addition, bohaii would face more extreme weather events (e.g., drought and wildfires, see Karuk et al 2021, Yasunari et al 2021 while experiencing both higher predation rates and increased competition for breeding space as more species and populations become concentrated in the Arctic rim (Killengreen et al 2007, Layton-Matthews et al 2020, Vallejos et al 2020. These factors might partially explain the decline of wintering waterbirds breeding in Siberia compared to temperate Asia (Sung et al 2021).…”

An emerging coastal wetland management dilemma between mangrove expansion and shorebird conservation

“…Shenzhen Bay is located at the Pearl River Estuary in southeast China. The wetlands around the bay provide important wintering and stopover habitats for about 40,000 migratory shorebirds (Choi et al., 2020; Sung et al., 2021), including 4 critically endangered or endangered and 9 near‐threatened shorebird species (Figure 4, Q1‐High). Mangroves have expanded in the bay for the last 3 decades, mainly through natural dispersal (Figure 2b).…”

“…Mangroves occur in the intertidal zone, where they are regularly inundated by seawater, and are most abundant and diverse in the tropics (Giri et al, 2011). Mangrove ecosystems provide important ecosystem services, including shoreline protection (Sun & Carson, 2020), water quality and climate regulation through carbon storage (Donato et al, 2011;Lovelock & Reef, 2020;Murdiyarso et al, 2015), pollutant uptake and nutrient cycling (UNEP, 2014), food and nursery grounds for com-mercially important fishes and invertebrates (Aburto-Oropeza et al, 2008;Ronnback, 1999), and nesting habitat for coastal birds. Value estimations of mangrove ecosystem services range from US$4217 to $6938 per km 2 annually (Himes-Cornell et al, 2018).…”