Vigilance behavior of common crane Grus grus in flocks during spring, summer, and autumn

Vigilance is a key behavioral element aimed to detect potential predators or rivals. In this study, we examined the vigilance levels of common cranes that exhibit flocking behavior during the spring, summer, and autumn seasons. We considered the influence of both social (age, presence of offspring, and flock size) and environmental factors (habitat type, time of day, and study period). Parents allocated more time for vigilance than nonparents and juveniles. The alertness of nonparents was lower in flocks of size 51–150 individuals compared to flocks under 50 and over 150 birds. Juveniles increased their vigilance at the end of the premigration period. Habitat type and time of day did not affect crane vigilance levels.