Four species of sviftlet (Ayes: Apodidae), thvo of which produce 'edible nests', occur
spmpatrically in Malaysia. Food boluses Lvere analysed to investigate (1) diet differences
and resource partitioning among the four species and (2) the influence of habitat on
the diet of the Glossy SIviftlet Collocalia esculenta. Hymenoptera and diptera were the
most abundant prey in all diets. Black-nest Swiftlets Aerodramus maximus were
extremely selective; 89% of the items taken were hymenoptera, of which 97% were flying
ants. White-nest Siviftlets A. fuciphagus and Mossy-nest Swiftlets A. salanganus took
more than twice as many prey items as either of the other species. Their diets were
taxonomically diverse and differed only in the average prey size taken, Mossy-nest
Sw-iftlets talung the larger prey. Glossy Swiftlets took a higher proportion of coleoptera
than ifid the other species. For the habitat comparisons, diptera were the main constituents
of the Glossy Swiftlet diet in an urban habitat (71Yo of total prey items), whereas
hymenoptera predominated in forest habitat (42% of total prey items). The results suggest
that diet separation occurs among the four species of Malaysian swiftlet, in relation to
both species and habitat. The implications of potentially habitat-driven dietary changes
are discussed for the edible-nest swiftlets.