Temporal pattern of exploratory behavior during 24-hour sessions in a Japanese monkey (Macaca fuscata) troop

The temporal pattern of exploratory behavior of a troop of Japanese monkeys to a novel apparatus introduced into their habitat was examined during four successive 24-hour periods. An "exploratory behavior" was defined as a press to a transilluminated panel within the apparatus. These presses had no scheduled consequences. The results showed that: (1) there was no responding from 1900 to 0600 hours; and (2) that day-time responding was bimodal, with activity peaking between 1000 and 1100, and 1600 and 1700 hours. These findings were discussed in terms of field studies and operant-based research which have studied diurnal processes in monkeys.