Maternal and social status affect hair cortisol concentrations in brown bears

Hair cortisol concentration is affected by different biological factors, including age, sex, and reproductive status, and can provide important insights into fitness. Using cortisol concentrations of wild Scandinavian brown bears, Ursus arctos, the purpose of this study was to investigate cortisol v...

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Detalles Bibliográficos
Autores: Franchini, Marcello, Mikkelsen, Ashlee J., Sergiel, Agnieszka, Selva, Nuria, Janz, David M., Kindberg, Jonas, Zedrosser, Andreas
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/393108
Acceso en línea:http://hdl.handle.net/10261/393108
https://api.elsevier.com/content/abstract/scopus_id/86000783299
Access Level:acceso abierto
Palabra clave:Brown bear
Cortisol
HPA axis activity
Physiological response
Reproduction
Scandinavia
Ursus arctos
Descripción
Sumario:Hair cortisol concentration is affected by different biological factors, including age, sex, and reproductive status, and can provide important insights into fitness. Using cortisol concentrations of wild Scandinavian brown bears, Ursus arctos, the purpose of this study was to investigate cortisol variations among individuals in relation to age, sex, and reproductive status (solitary individuals vs individuals in a family group). Cortisol concentrations were measured in 448 hair samples of 303 brown bears (162 males and 141 females, from one to nine years of age) captured from 1990 to 2016. We found that members of family groups, i.e., mothers as well as their dependent offspring, had significantly higher cortisol concentrations compared to solitary individuals (males or females). Higher energetic costs in family groups are likely linked to growth of the offspring as well as maternal costs incurred by the rearing of offspring. Our findings provide valuable insights into the physiological effects of maternal care and reproductive status in mammals.