Antipredatory vigilance usually decreases in groups. The generally accepted "collective detection" explanation implies that because there are more eyes to scan the surroundings for predators, individuals in a group can lower their personal investment in vigilance without increasing their...

In many species, foraging in groups can enhance individual fitness. However, groups are often predicted to be larger than the size that maximizes individual fitness. This is because individual foragers are expected to continue joining a group until the fitness in the group falls to the level...

Group foraging has been proposed to be the most efficient manner with which to exploit habitats with renewing patches as individuals in groups are less likely to revisit patches that have already been exploited recently by others. However, to avoid a group-selection argument, it is necessary to...

False alarms occur when animals flee abruptly upon detection of a threat that subsequently proved harmless. False alarms are common in many species of birds and mammals and account for a surprisingly high proportion of all alarms. False alarms are expected to be more frequent in larger groups,...