; one roost I watched in mangroves at Pulau Tengah, Selangor, was used by tens of thousands of birds, and reportedly still held 5,000–10,000 birds in the 1980s (Nisbet, 1968b; Wells,1999). One bird ringed at Sungei Way on 13 Jan.1965 was retrapped there on 10 Feb.1966, showing fidelity to the wintering site.