Gazing Strategies among Sentinels of a Cooperative Breeder Are Repeatable but Unrelated to Survival

Simple Summary Animals can detect threats through their vigilance. Many studies indicate that traits such as vigilance are repeatable among individuals over time suggesting differences in the ways individuals respond to risk. Little is known about individual consistency in the ways vigilance is achieved from one moment to another and whether among-individual differences in vigilance are related to survival. Using sentinels of a cooperative breeder, the Florida scrub-jay (Aphelocoma coerulescens), we examined the occurrence of stable individual patterns of vigilance during sentinel bouts and their association with survival. During sentinel bouts from vantage points, Florida scrub-jays turn their heads from side to side to monitor their surroundings for threats such as intruding neighbours or predators. Using data from three field seasons, we found that the head-turning frequency was repeatable in breeders but not in younger birds and was not clearly associated with survival. Younger birds typically have less experience with threats, which might mitigate against the occurrence of consistent individual differences at that age. The lack of association between the head-turning frequency and survival was not expected. Future studies are needed to validate this crucial assumption of vigilance in animals.Abstract Vigilance is a common behavioural adaptation to increase the chances of detecting predators before it is too late to escape. Behavioural traits are often repeatable among individuals over the long term, suggesting differences in personality. Earlier studies have documented individual consistency in the time allocated to vigilance. However, little is known about individual consistency in the ways vigilance is achieved from one moment to another and whether different patterns of vigilance among individuals are associated with survival. We aimed to determine whether sentinels of a cooperative breeder showed individual consistency in their vigilance and if individual variation was related to annual survival. During sentinel bouts from vantage points, Florida scrub-jays (Aphelocoma coerulescens) turn their heads from side to side to monitor their surroundings. Over three field seasons, we found that the head-turning frequency was repeatable in breeders but not in juveniles or non-breeding helpers. The moderate repeatability in breeders was not related to survival. Our results suggest that the head-turning frequency in sentinels of the Florida scrub-jay is repeatable in breeders but not in less experienced juveniles or helpers and, therefore, likely becomes more repeatable as individuals age. The assumption that individual variation in vigilance is related to survival was unsupported in our study and requires further study.