Effects of hydrological variation on the population dynamics of Chilean Flamingo (Phoenicopterus chilensis) at the Ramsar site Llancanelo lagoon, Mendoza, Argentina

Wetlands are habitats where water plays a fundamental role in the structuring of ecosystems and population dynamics. In the south of Mendoza (Argentina), the Llancanelo lagoon constitutes a Ramsar site of continental importance and hosts a great diversity of birds, the Chilean Flamingo (Phoenicopterus chilensis) being particularly abundant. The monitoring of species, in the long term, and its link with the hydrological variability in wetlands is essential to develop strategies for the protection and management of wildlife and its environment. Here we evaluated the relationship between abundance and breeding of the Chilean Flamingo with the variations of Llancanelo lagoon size, defined as the surface covered by water. The size of the lagoon was estimated from an index applied to Landsat images, the MNDWI (Modified Normalized Difference Water Index), from 1987 to 2016. The available information allowed a 30-year analysis of data on the abundance of flamingos and breeding events. The results show that breeding colonies are established when there are large concentrations of individuals. The abundance of flamingos and the water surface area have a positive and linear relationship up to a lake size of 80 km(2). Beyond this threshold, if the area of the wetland increases, the number of individuals decreases significantly. Long-term monitoring can complement the management of water resources in the upper reaches of the basin and the conservation of Chilean Flamingos in the Llancanelo lagoon.