Distribuição Espacial e Temporal da Avifauna Aquática no Lago de Santo Amaro, Parque Nacional dos Lençóis Maranhenses, Maranhão, Brasil.

Abstract

The aim of this work was demonstrate the spacial and temporal distribution of resident and migratory waterbirds in Santo Amaro Lake, municipality of Santo Amaro do Maranhão, in the West side of Parque Nacional dos Lençóis Maranheses, Maranhão State. This lake has 6000 ha total area and in the reason of it s huge extension it was splited in three places: Alagadiço (2200 ha), near Santo Amaro municipality and fulltime flooded; Guaperiba/Ponta Verde Lake (2200 ha), with sandbanks and open areas, presenting a quick decreasing of the water level; and Taquari Lake (1600 ha), with most of It s margin surrounded with dunes and huge open areas, fulltime flooded, but without macrophitas, presenting only sandbank vegetation. During the rainy season the observer conducted the census from the motorboat at a velocity of 6 km/h, percurring a transect paralell to the lake s margin. In dry station the census was made through a fixed point using animal tracking for locomotion. A total of 3.335 waterbirds were counted with 18 species. The resident birds had greater abundance in the rainy season. The most exploited site in both seasons was Alagadiço. The dry season presented greater abundance of migratory birds corresponding to their arrival from breeding areas in Northern Hemisphere. In both seasons Taquari lake was the most exploited by those birds. Resident birds breeds in Santo Amaro Lake in the rainy season and the gulls - believed as an isolated population - used the Lake to foraging while breeding in the dunes near Taquari lake. It s very important to create a management plan for the Parque Nacional dos Lençóis Maranhenses, specially to Santo Amaro Lake, being the lake used by a great diversity of resident and migratory waterbirds and used by the humans in the subsisting fishery activities. The sustainable use of the Lake warrants the Biota continuity on it, what also assure a good life condition for the people around Santo Amaro Lake.