Although nocturnal predation is a major cause of animal mortality, antipredator behavior at night is poorly understood. To investigate how diurnal animals adjust their antipredator behavior during these different conditions, we exposed peahens to a taxidermy raccoon during the daytime and nighttime. During the day, the peahens emitted loud antipredator calls, extended their necks upward, adopted a preflight posture, and approached the predator; at night, the peahens emitted soft hissing calls, remained stationary, piloerected their feathers, and raised their tails. The results demonstrate that birds adopt radically different antipredator behavior depending on whether the threat occurs in the daytime or nighttime. Videos showing nocturnal and diurnal antipredator behavior of peafowl (Pavo cristatus) are available online.
Yorzinski, J.L. & Platt, M.L. 2012. The difference between night and day: antipredator behavior in birds. Journal of Ethology 30: 211-218. PDF