The diurnal behavior of members of a harem group of the big fruit-eating bat, Artibeus lituratus, in Mérida, Venezuela was investigated while they roosted beneath palm leaves. Behaviors were recorded applying a digital video camera to characterize diurnal activities, and from these an ethogram was constructed. Scan sampling and focal sampling were used to analyze the recorded behaviors. Four long behavioral states and seven short behavioral events were distinguished. During the diurnal period, most bats were inactive and were presumed to be sleeping, although at least one individual always remained active and alert. The fact that at least one bat was always alert during the day-roosting period suggests that some level of vigilance may be needed for bats to successfully occupy exposed roosts. Although the bats were inactive more than 80% of the day-roosting period, this was an interrupted phenomenon since individuals did not sleep continuously for more than 20 min (on average) when they were observed sleeping. Differences between the single harem male and an associated female were significant in terms of the frequency of states and events, and duration of some behavioral states. The harem male was active (i.e. alert) 13% of time of the diurnal period, whereas the female was active 1% of the time during this same period. Differences may be related to predation risks or actual and potential incursions of other males into the roost. The male allocated 4% of his time to grooming, whereas the female allocated 9% of her time to grooming, which may be related to the female's reproductive condition.