Which factors can influence budgerigars' feeding behavior under predation risk: individual and/or social factors?

Abstract Animals face a fundamental risk-reward trade-off when making feeding decisions in the presence of predation. This trade-off requires balancing time spent being vigilant with time spent feeding under predation risk, influenced by both individual and social factors. However, it remains unclear which factor plays a more significant role. In this study, we aimed to determine whether individual factors (sex, personality, and body condition) and social factors (social familiarity and social rank) influence feeding and vigilance behaviors under predation risk. When alone with the predator, budgerigars with longer tarsus length exhibited shorter latency to feed, and bold budgerigars tended to have a lower frequency of scans, but neophobia and body condition did not influence these behaviors. When facing the predator with familiar group members, individuals showed shorter latency to feed, and a lower frequency of scans compared to when with unfamiliar group members or alone. Moreover, social rank was the most important factor affecting latency to feed. Our findings suggested that both individual and social factors can influence budgerigars' foraging behaviors, with social factors playing a more significant role than individual factors when individuals are in a group.