Tent Construction by the Short-nosed Fruit Bat Cynopterus sphinx (Chiroptera: Pteropodidae) in Southern India

The short-nosed fruit bat Cynopterus sphinx (Chiroptera: Pteropodidae) constructs shelters by severing stems of the curtain creeper, Vernoniu scundens, and stems and leaves of the mast tree, Polyalthia longifoliu, creating partially enclosed cavities (stem tents) in which to roost. Our observations indicate that the construction and maintenance of stem tents are primarily, if not exclusively, the behaviour of single males. A stem tent is formed in V. scundens when a single male C. sphinx severs up to 300 small- to medium-sized stems creating a partially flattened, bell-shaped cavity, and in P. fongifolia when a male severs a few medium- to small-sized branches and many leaf petioles, creating an entry/exit portal and space in which to roost. A tent constructed in V. scandens is completed in approximately 30 d, whereas one in P. longifoliu is completed in about 50 d. Stem-tent construction takes place mostly at night, but some stem chewing occurs in late afternoon. At night a stem tent is occupied by a single male, whereas females are usually absent. During the day the number of bats occupying completed tents is highly variable, ranging from two to 19 females (and their pups) and a single adult male. Tent construction is annually bimodal, which corresponds to a biannual breeding season. A dominant male sometimes deposits saliva on branches inside his tent cavity and actively defends this space from intrusions by other males. Both behaviours suggest forms of scent marking and territorial display. Our observations indicate that dominant males construct tents, recruit females and then defend the tents (and their female occupants) for the purpose of gaining reproductive access. The variance in harem group size indicates that some tent-making males are more successful than others in recruiting females.