Migratory Waterbirds Response to Coastal Habitat Changes: Conservation Implications from Long-term Detection in the Chongming Dongtan Wetlands, China

Abstract

Changes in waterbird populations in relation to changes in their habitat are of great concern in the Chongming Dongtan wetlands, one of the most important stopovers for migrating waterbirds in the East Asian–Australasian Flyway. We analyzed the relationship between the changes in the dominant waterbird populations (Charadriidae, Anatidae, Ardeidae, and Laridae) and the changes in their corresponding habitats from 2000 to 2012. In natural wetlands, the species number of Anatidae was significantly positively correlated with the Scirpus mariqueter (hereafter Scirpus) habitat but significantly negatively correlated with the Phragmites australis (hereafter Phragmites) habitat. The densities of Charadriidae and Laridae were both significantly positively correlated with the deep water habitat but significantly negatively correlated with the Spartina alterniflora (hereafter Spartina) habitat. The density of Charadriidae, however, also exhibited significantly positive correlation with the Scirpus habitat. In the aquaculture ponds, the changes in the density of Anatidae in the winter were significantly negatively correlated with the changes in aquaculture ponds. Other waterbirds only exhibited positive or negative correlation trends with their habitats, which did not reach the statistically significant levels. Consequently, changes in waterbird populations are significantly correlated with changes in natural wetlands and aquaculture ponds in the Chongming Dongtan wetlands. Natural wetlands and aquaculture ponds are important to migratory waterbirds during the peak of migration and wintering. Our results promote the development of wetland management strategies for protecting migratory waterbirds in the coastal area of the Yangtze River.