I have recently started on another exciting collaboration with my good friends and colleagues Yaara Aaron-Rotman and Lei Cao at the Research Centre for Eco-Environmental Sciences, the Chinese Academy of Science in China. The Poyang Lake is one of the largest wetlands in Asia and a critical wintering area for migratory waterbirds along the East Asian Australasian Flyway. Its unique hydrological system allows the production of large biomass of plants and animal food. The main driver for this wealth of food is the high yearly variation in water level. In the summer rainy season water level is high, and in the winter dry season, water level is shallow, allowing birds of different feeding guilds to take advantage of the abundant food supply.
Numbers of some species of geese on the lake have declined sharply, probably due to reduction in tuber producing Vallisneria (the species’ main food) in muddy lake sediments. This reduction is linked with aquaculture and reduction in submerged vegetation (and increase in floating macrophytes and grass). Three Gorges Dam (TGD) may be responsible for some of the changes by reducing access to shallow water.
This project utilises data from satellite tracking of key waterfowl species like swan goose (Anser cygnoides) and greater white fronted goose (Anser albifrons) in conjuntion with detailed vegetation maps to investigate the effects of changing water levels in the lake on the distribution of vegetation types and the ecology of wintering geese which rely upon this area for vital refuelling before embarking on long migratory journeys.
I am helping out with the analysis of movement data and modelling habitat selection under contrasting scenarios of water depth and food abundance. We are getting close to wrapping up the analysis so stay tuned for info on publications.