PUNTA RASA, ARGENTINA AS A MIGRATORY STOPOVER AND OVERSUMMERING AREA FOR THE RED KNOT (Calidris canutus rufa)

MARTÍNEZ CURCI N.S.; BREMER, E; CASTRESANA G; BATTAGLIA, G; AZPIROZ, AB; ROJAS P; SALERNO, JC; BALA, LO

Congreso; 5 th Western Hemisphere Shorebird Group Meeting; 2013

The importance of Punta Rasa (the southern tip of Samborombón Bay) in the migration of the Red Knot was assessed two decades ago. Since then, and despite being mentioned in the conservation plan for the species as a critical migratory stopover, few studies have been conducted and no data was collected after the decline early in the millennium. Here we gather published and unpublished historical records (since 1985), and recent observations on abundance and habitat use patterns of Red Knots at Punta Rasa and surrounding areas. Observations of habitat use patterns indicate that birds used the interior coasts of Samborombón Bay for feeding during low tide while Punta Rasa was used during high tide when feeding areas are covered by water. Samborombón has 120 Km of mostly inaccessible coastline and Red Knots in the area may be underestimated when surveying only Punta Rasa. About 140 individuals remained in the area during the boreal summers of 2012 and 2013, which results in an over-summering index of about 1% with respect to the wintering population at Tierra del Fuego. In 2012 we started a banding program focused on oversummering Red Knots. Given that the population status of the taxon is critical there is a need to conduct surveys along the whole Bay in order to determine its importance for this shorebird. It is also important to evaluate hypotheses about the reasons some individuals do not migrate.