Extensive loss of natural wetlands caused by changes in land use largely diminishes the food resources essential for the survival of migratory waterbirds. Globally, the decline in waterbird populations in East Asia is the most serious, with 64% of these populations showing a decreasing trend. In this study, we applied DNA metabarcoding to examine the spatiotemporal variations and diversities in the dietary compositions of migratory waterbirds in a natural/artificial wetland complex in Asia. By investigating 110 fecal samples from the endangered black-faced spoonbill (Platalea minor) wintering in the wetland, our results show that P. minor had a broad dietary spectrum. The birds fed on at least 26 species in the classes Actinopterygii and Malacostraca, with Mugiliformes, Cichliformes, and Gobiiformes being the main taxa in their diets. Our results also demonstrated clear patterns of the spatiotemporal variations between the roosting groups and intraspecific variations between the individuals, which potentially reflect some of their feeding habits, and the probable usage of different habitat types in the wetland complex. Using high-throughput sequencing, we were able to elucidate the food resources that are critical to P. minor non-invasively, this method can also be used to provide invaluable information for the conservation of many other waterbird species.
Bibliographical noteFunding Information:
This research was supported by the AFCD of HKSAR government (AFCD/SQ/144/18/C). We would like to thank Paul J. Leader of AEC Limited, Yat Tung Yu of the Hong Kong Bird Watching Society, Hak King Ying, and David Tsz Chung Chan for their assistance on sample collection; World Wide Fund for Nature Hong Kong and MTR Corporation for granting permissions to enter Mai Po Nature Reserve, and LMC Ecological Enhancement Area, respectively. We also thank Ka Shing Cheung for his comments on the manuscript. The computations were performed using research computing facilities offered by the Information Technology Services, the University of Hong Kong.
© 2021, The Author(s).