Plovers and Sandpipers Census in Bahia Nueva (Puerto Mdryn, Chbut)

Seasonal abundance and distribution of plovers and sandpipers on the shores of the Golfo Nuevo, in the vicinity of Puerto Madryn were analyzed. Weekly census were made from April 1984 to September 1986. Twelve species of plovers and sandpipers were identified. The seasonal abundance of the most common species (<i>Charadrius falklandicus, Calidris alba, Calidris fuscicollis, Calidris bairdii</i> and <i>Pluvianellus socialis</i>) was related with the mean weekly amplitude of the photoperiod for this latitude. Acording to the timing of arrival, departure and the length of time the species remained in the area. Three behavioural patters were identified. Shorebirds concentrated on the shores of Puerto Madryn whenever the photoperiod amplitude is between 14 hrs of dayligth at lhe earIy March and 13 hrs of dayligth at the end of September. When the photoperiod amplitude reaches maximum values (summer) these shorebirds were not present