Increases and decreases of waterfowl population have been used as an indicator of water quality and habitat quality. The aim of this paper was to survey and monitor waterfowl population at the largest natural lake of the 'Area of Environmental Protection' of Lagoa Santa, Southeast Brazil. The 'Lagoa do Sumidouro' holds approximately 253 ha with a 12,072 m of perimeter. Species richness and abundance was estimated from June 1999 to December 2002. It was recorded 27 species of 12 families. Twelve species were considered residents, while eight migratory and another seven species did not present any seasonal pattern. Ardeidae was the most representative family holding 23% of the species followed by Anatidae (15%) and Socolopacidae (11%). Platalea ajaja Linnaeus, 1758 is considered threatened to extinction, while Mycteria americana Linnaeus, 1758 and Ciconia maguari (Gmelin, 1789) are considered rare for the state of Minas Gerais. There was no difference of species richness among the three main seasons ('wet', 'dry', and 'transitional'). Species diversity was higher during the wet season. The occurrence of threatened and migratory species at 'Lagoa do Sumidouro' makes the lake an area of extreme biological importance.
Biodiversity; bioindicator; Cerrado; migration; Platalea ajaja; Minas Gerais
