The difference between night and day: antipredator behavior in birds

Animals have evolved sophisticated strategies for avoiding predators during the day. These strategies can vary depending on the type of predator and level of threat. 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, peahens (Pavo cristatus) were exposed 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. These different tactics could result from limitations in sensory abilities. Videos showing nocturnal and diurnal antipredator behavior of peafowl are available online (http://www.momo-p.com/showdetail-e.php?movieid=momo111110pc01a and http://www.momo-p.com/showdetail-e.php?movieid=momo111110pc02a).