The population size, diet, foraging area and breeding biology of White-nest Swiftlets Aerodramus fuciphagus were studied at Suthiwararam Temple, Samut Sakhon Province during August 2000 and October 2001. The nest morphology and nest-site characteristics were compared to those living at Si-Ha Islands, Phatthalung Province. The population size of White-nest Swiftlets was 2,702 individuals at the beginning of the study period during which they performed continuous breeding pattern. Average times of nest building, incubation and nestling feeding were 29.83 ± 6.3, 23.63 ± 1.6 and 40.25 ± 3.0 days, respectively, with 15.94 ± 10.5 days for subsequent brood. The two-egg clutch was the normal clutch size with the laying interval of 3.36 ± 2.5 days. The highest percentages of egg laying, hatching success and breeding success at fledging was in April. Parental investments in egg incubation, brooding and nestling feeding were not significantly different between sexes. Breeders paired and had nest-site fidelity throughout the study period. Nestlings were fed mainly with dipterans, homopterans, hymenopterans with the average of 5.35 food balls/day and the rate was influenced by the brood size and the age of nestlings. Adults were frequently seen foraging over rice fields, orchards, coconut plantations and swamps with the longest distance of 25 km from their breeding sites. The breeding success at fledging was affected by the quality of nesting sites, leading to the average production of 3.55 . 2.3 fledglings/pair/year. Nests from caves were thicker, wider and heavier than those from the temple. The experiment on the use of artificial nest-sites by swiftlets living in the sacred building, in which the nest-site characteristics at caves were imitated, was successful. The application of the artificial nest-site model would be useful to increase the production in cultivated houses in the future.
