Paper Title
Cave Swiftlets in Agusan Del Sur, Philippines

Abstract
Caves serve as habitats to various vertebrates especially cave swiftlets. This study was conducted to determine the cave swiftlets present in six caves of Agusan del Sur. Two species of swiftlets, namely: Collocalia esculenta and Collocalia troglodytes with a total of 204 individualsand 102 nests were documented. C. esculenta was the most abundant species having 106 individuals found only in Wilderness Cave, Magdagohong Cave, and Katam-isan Cave while only 98 individuals of C. troglodytes were found only in Wilderness Cave, Ararat Cave and Katam-isan Cave.C. esculenta and C. troglodytes were observed toinhabit and nest in the deep zone of the caves. Among the sampled caves, Wilderness Cave had the most number of swiftlets having 138 bird individuals and 69 nests. Nesting sitesof C. esculentawere on high cave ceiling in the deep zone (53 nests) while nests of C. troglodytes were on low cave ceiling in the twilight zone (2 nests) and deep zone (47 nests). Nests of both species were found on the same cave chamber. It was observed that if bats are present, these cave dwelling birds are not present and thus, the higher the bat population the lower the cave bird population. Major threat observed for the cave-dwelling birds was nest gathering. Most of the caves were also observed to be disturbed as seen from vandalism and destroyed stalactites and stalagmites. The presence of C. troglodytes, an endemic species with edible nests, in most of the caves indicates the need to conserve the caves and protect the swiftlets and their habitats in Agusan del Sur. Keywords� Cave-Dwelling Birds, Collocalia, Mindanao, Stalactites, Stalagmites.