Waterbird occurrence and abundance in the Strobel plateau, Patagonia, Argentina

LANCELOTTI, J.; POZZI, L.; MÁRQUEZ, F.; YORIO, P.; PASCUAL, M.

El Hornero

Asociación Ornitológica del Plata

Lugar: Buenos Aires; Año: 2009 vol. 24 p. 13 - 20

0073-3407

The Lake Strobel Meseta is a conspicuous and representative basaltic “meseta” in the Patagonian steppe, Argentina. This “meseta” is spotted by more than 1500 shallow lakes which are regularly used by waterbirds and support one of the main breeding populations of the threatened Hooded Grebe (Podiceps gallardoi). We collected data on bird presence and abundance at the species level in 41 shallow lakes, covering a wide spectrum of the wetland environmental variability found in the area. We conducted six surveys from spring to fall between 2004 and 2006. We recorded a total of 18 waterbird species, which represent five and six different families and orders, respectively. Anatidae was the family most represented with 12 species, accounting for 85% of the observed waterbirds. Waterbird distribution among lakes was variable, from 2.8% occupied lakes for the Wilson’s Phalarope (Steganopus tricolor) and Andean Duck (Oxyura ferruginea) to 80% for the Black–necked Swan, and abundance varied greatly both between species and seasons. The threatened Hooded Grebe, in particular, was recorded in 14 lakes (1–81 individuals). Six species bred in the area: Hooded Grebe, Flying Steamer–duck (Tachyeres patachonicus), crested duck (Anas specularioides), Silvery Grebe (Podiceps occipitalis), Upland Goose (Chloephaga picta), and White–winged Coot (Fulica leucoptera). Hooded Grebes nested at four lakes, three of them not previously known to hold breeding birds. Results point to the need of further studies on the dynamic nature of waterbird lake use to adequately assess the importance of the Lake Strobel Meseta as waterbird habitat.