Experience buffers extrinsic mortality in a group-living bird species
Autor: | Franziska Kurz, Katharine M. Bowgen, Enrico Sorato, Anssi Laurila, Michael Griesser, Emeline Mourocq, Magdalena Nystrand, Radoslav Kozma, Jonathan Barnaby, Kevin Fletcher, Sönke Eggers, Jan Ekman |
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Rok vydání: | 2017 |
Předmět: |
0106 biological sciences
0301 basic medicine endocrine system biology Ecology Proportional hazards model Foraging food and beverages Accipiter Group living biology.organism_classification Safety in numbers 010603 evolutionary biology 01 natural sciences Predation 03 medical and health sciences 030104 developmental biology Breeding pair Juvenile Ecology Evolution Behavior and Systematics Demography |
Zdroj: | Oikos. 126:1258-1268 |
ISSN: | 0030-1299 |
DOI: | 10.1111/oik.04098 |
Popis: | 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. |
Databáze: | OpenAIRE |
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