TY - JOUR

T1 - Testing Cort-Fitness and Cort-Adaptation hypotheses in a habitat suitability gradient for roe deer

AU - Escribano-Avila, G.

AU - Pettorelli, Nathalie

AU - Virgós, E.

AU - Lara-Romero, Carlos

AU - Lozano Mendoza, Jorge

AU - Barja, I.

AU - Cuadra, F.S.

AU - Puerta, Marisa

PY - 2013/11

Y1 - 2013/11

N2 - According to the Cort-Fitness Hypothesis, higher stress levels (glucocorticoids) in vertebrates are correlated to lower fitness. However, recent studies have failed to validate this hypothesis. A proposed wider framework suggests that reproduction can be perceived as an overload adds up to other environmental challenges that individuals must adjust to. In this case, elevated glucocorticoids could help individuals to allocate resources to reproduction without comprising other functions, leading to the expectation of a positive cort-fitness relationship. This has been proposed as the Cort-Adaptation Hypothesis. Stress levels result from a complex interaction between the environment and the neuroendocrine system of animals. Accounting for physiological functions involved in how animals cope with their environment would help to clarify the relationship between glucocorticoids and animal performance. We used roe deer (. Capreolus capreolus) inhabiting diverse habitats in the Iberian Peninsula to: i) test the Cort-Fitness and Cort-Adaptation hypotheses by indexing fitness using a comprehensive physiological approach which takes into account fundamental physiological functions and their trade-offs; and ii) evaluate the link between primary productivity and individuals' condition in a seasonal environment. We evaluated spatial and temporal variation in stress levels, reproductive hormone levels, nutritional status and immune function from fecal samples collected in 2010. Lower stress levels were related to better condition in non-reproductive seasons but not to higher primary productivity. In contrast, stress levels were always positively related to reproductive condition, which was better in most productive habitats. Summer and winter were the less productive seasons and the more challenging for the species in the habitat gradient studied. In winter, reproductive condition traded off against immune function being biased toward immune function in less productive habitats. In summer reduced primary productivity limited roe deer nutritional and immunological condition but not reproductive condition. Overall our results match both the Cort-Fitness and Cort-Adaptation Hypotheses. © 2013 Elsevier Masson SAS.

AB - According to the Cort-Fitness Hypothesis, higher stress levels (glucocorticoids) in vertebrates are correlated to lower fitness. However, recent studies have failed to validate this hypothesis. A proposed wider framework suggests that reproduction can be perceived as an overload adds up to other environmental challenges that individuals must adjust to. In this case, elevated glucocorticoids could help individuals to allocate resources to reproduction without comprising other functions, leading to the expectation of a positive cort-fitness relationship. This has been proposed as the Cort-Adaptation Hypothesis. Stress levels result from a complex interaction between the environment and the neuroendocrine system of animals. Accounting for physiological functions involved in how animals cope with their environment would help to clarify the relationship between glucocorticoids and animal performance. We used roe deer (. Capreolus capreolus) inhabiting diverse habitats in the Iberian Peninsula to: i) test the Cort-Fitness and Cort-Adaptation hypotheses by indexing fitness using a comprehensive physiological approach which takes into account fundamental physiological functions and their trade-offs; and ii) evaluate the link between primary productivity and individuals' condition in a seasonal environment. We evaluated spatial and temporal variation in stress levels, reproductive hormone levels, nutritional status and immune function from fecal samples collected in 2010. Lower stress levels were related to better condition in non-reproductive seasons but not to higher primary productivity. In contrast, stress levels were always positively related to reproductive condition, which was better in most productive habitats. Summer and winter were the less productive seasons and the more challenging for the species in the habitat gradient studied. In winter, reproductive condition traded off against immune function being biased toward immune function in less productive habitats. In summer reduced primary productivity limited roe deer nutritional and immunological condition but not reproductive condition. Overall our results match both the Cort-Fitness and Cort-Adaptation Hypotheses. © 2013 Elsevier Masson SAS.

KW - Environmental change

KW - Habitat quality

KW - Immune function trade-off

KW - Non-invasive

KW - Stress

KW - deer

KW - environmental stress

KW - fitness

KW - habitat quality

KW - immune system

KW - physiology

KW - reproductive productivity

KW - steroid

KW - trade-off

KW - Sustainability Science

UR - http://www.scopus.com/inward/record.url?scp=84884236636&partnerID=8YFLogxK

U2 - 10.1016/j.actao.2013.08.003

DO - 10.1016/j.actao.2013.08.003

M3 - Journal articles

VL - 53

SP - 38

EP - 48

JO - Acta Oecologica

JF - Acta Oecologica

SN - 1146-609X

ER -