Most cooperative breeding bird species live in family groups that are formed through the prolonged association of offspring with their parents. Research into cooperative families has in particular investigated the balance between cooperation and conflict over reproductive decisions. As a consequence of this research focus, social interactions among group members outside the breeding season are rarely studied, despite the fact that they are likely to be crucial for social decisions. We investigated the social dynamics and ranging behaviour of the family group living cooperatively breeding apostlebird (Struthidea cinerea) outside the breeding season. Group size changed between, but not within, the seasons, being smaller during the breeding season than in the winter season. This change in group size was a consequence of breeding groups merging after breeding, then splitting again before the next breeding season. While breeding groups used small, non‐overlapping home ranges ( = 113 ha) around the nesting site, during winter groups moved up to 1200 ha ( = 598 ha), and interacted frequently with up to four other winter groups. In particular large groups often joined together during winter and spent up to 50% of their time associating with other large winter groups. This apparent fission‐fusion system facilitated the exchange of group members, offering the possibility to form new breeding coalitions and new groups. The results of this study suggest that behaviour outside the breeding season can be of considerable importance to the social dynamics of both families and cooperative breeding in such systems.

Extrinsic mortality has a strong impact on the evolution of life‐histories, prey morphology and behavioural adaptations, but for many animals the causes of mortality are poorly understood. Predation is an important driver of extrinsic mortality and mobile animals form groups in response to increased predation risk. Furthermore, in many species juveniles suffer higher mortality than older individuals, which may reflect a lower phenotypic quality, lower competitiveness, or a lack of antipredator or foraging skills. Here we assessed the causes of mortality for 371 radio tagged Siberian jays. This sedentary bird species lives in family groups that contain a breeding pair as well as related and unrelated non‐breeders. Ninety‐five percent of death were due to predation (n = 59 out of 62 individuals) and most individuals were killed by Accipiter hawks. Multivariate Cox proportional hazards models showed that non‐breeders had a lower survival than breeders, but only in territories in managed forest with little visual cover. Examining breeders, only sex influenced survival with males having a lower survival than females. For non‐breeders, juveniles had lower survival than older non‐breeders, and those on managed territories had lower survival than those on unmanaged territories. Additionally, a low feather quality reduced the survival probability of non‐breeders only. Thus, living on managed territories and having a low feature quality affected only non‐breeders, particularly juveniles. These findings add to previous research demonstrating that juvenile Siberian jays acquire critical antipredator skills from experienced group members. Thus, experience can buffer extrinsic mortality, highlighting that group living not only provides safety in numbers, but also provide social opportunities to learn critical life‐skills.

The Pleistocene ice age and recent forest fragmentation have both played a significant role in shaping the population genetic variation of boreal coniferous species in the Qinghai-Tibet Plateau (QTP) and Eurasian coniferous forests. The Sichuan jay is one of the least know endemic bird species in QTP coniferous forests in western China while its sibling species, the Siberian Jay, is widespread within the coniferous forests in northern Eurasia. Here we used 11 microsatellite markers to assay genetic diversity across 58 Sichuan jay samples from China and 205 Siberian jay samples from Sweden and Russia. Results showed three distinct genetic clusters from the Sichuan jay sampling. Furthermore, the pair-wise F ST values indicated high genetic differentiation not only among the two species but also between Swedish and Russian Siberian jay populations. What is more, a pattern of isolation by distance was found among the analyzed populations. Our study suggests that targeted habitat restoration in fragmented forests and more genetic work is urgently needed for conservation of the Sichuan jay.