Corticosterone Response as an Age-Specific Mediator of Nestling Body Mass in a Wild Passerine

Abstract

The environment can affect individual performance directly via resource availability or indirectly through resource allocation among competing fitness components, such as body growth and maintenance activities related to short-term survival. Corticosterone (CORT), the main glucocorticoid in birds, may be an important mediator of energy allocation to different organismal functions, but its effect on the plasticity of fitness-related traits has rarely been investigated at different ontogenetic stages. Here, we evaluated the role of baseline and stress-induced CORT on nestling development of wild great tits (Parus major) under different growth conditions and at different developmental stages. We found that nestling mass and condition were positively related to stress-induced levels of total CORT and free CORT in the middle of nestling stage but negatively related at the prefledging stage. Our results also showed that stress-induced levels of total CORT can be used as a proxy for bioavailable free CORT. No significant relationship of body mass or condition in either stage was shown with levels of baseline CORT or stress-induced CORT-binding globulin capacity. None of these age-specific relationships depend on brood size manipulation. We conclude that the effects of glucocorticoids on nestling performance are stage specific. The ability to secrete CORT may have beneficial effects on nestling development in the middle of the nestling stage, while it can be adaptive to keep CORT levels at optimal ranges before fledging to give priority to growth-related processes that are important for long-term fitness.

Repeated stimulation of the pituitary–adrenal axis alters offspring phenotype of a wild passerine

“…Schwabl, 1999) and with my earlier studies (e.g. Tilgar et al, 2016Tilgar et al, , 2017. It has been shown in different passerine species that CORT levels reach a plateau approximately 15 min after capture (Lynn and Porter, 2008;Wada and Breuner, 2008).…”

Elevated temperatures are associated with stress in rooftop-nesting Common Nighthawk (Chordeiles minor) chicks

“…Corticosterone levels may vary in nestlings based upon their developmental strategy. For example, altricial nestlings, like barn owls, Tyto alba ( Almansi et al , 2009 ) and passerines ( Tilgar et al , 2017 ) have less developed hypothalamic–pituitary–adrenal (HPA) functionality at hatching and thus a lower stress response to poor environmental conditions, presumably due to allocation of resource investment to body growth. In contrast, chicks of semi-precocial species, such as Black-Legged Kittiwakes ( Rissa tridactyla ) ( Kitaysky et al , 2003 ), Red-legged Kittiwakes ( R. brevirostris ) ( Kitaysky et al , 2001 ), Tufted Puffins ( F. cirrhata ) ( Kitaysky et al , 2005 ), Ring-Billed Gulls ( L. delawarensis ) ( Chin et al , 2013 ), and Grey-faced Petrels ( Pterodroma macroptera gouldi ) ( Adams et al , 2008 ), have the capacity to mount a stress response.…”

To change or not to change experimenters: caveats for repeated behavioural and physiological measures in Montagu's harrier

“…It is particularly important to consider the sensitization process during research and conservation activities since it is linked to an increase in corticosterone due to stress during post-natal phase. Although the mechanisms are complex, an increased corticosterone secretion during nestling phase may compromise chick developmental plasticity in stopping (Spencer and Verhulst 2007) or enhancing growth rate (Tilgar et al 2017), may modulate their future behaviour (Müller et al 2009, Boogert et al 2014, may promote a higher susceptibility to oxidative stress (Noguera et al 2017) and/or may impact immunity (Chin et al 2013, Schmidt et al 2015, Virgin and Rosvall 2018. These consequences may alter chick survival, being critical for the conservation of endangered species.…”