Primary moult, biometrics, mass and age composition of Grey Plovers Pluvialis squatarola in southeastern India

Little is known about the biology of waders wintering in southern Asia; thi s paper deals with the Grey Plover Pluvialis squatarola, a species extensiv ely studied only in western Europe. Adult Grey Plovers wintering in southea stern India underwent primary moult in autumn; the duration was estimated t o be 127 days, with mean starting date 1 September and mean completion date 5 January. Some first-year Grey Plovers initiated primary moult in late wi nter and spring, and completed this moult the following spring. The average mass of adults on arrival in September was 200 g, fluctuated close to 220 g from October to February, and increased to 280 g near the end of May. The mass variation did not show the January peak observed in western Europe. B reeding productivity, measured as the percentage of first-year birds in win ter catches, varied between 5% and 70% over six years, and showed a positiv e correlation with that of Dark-bellied Brent Geese Branta b. bernicla in w estern Europe and Curlew Sandpipers Calidris ferruginea in South Africa.