Oxidative status of blue tit nestlings varies with habitat and nestling size Garrido-Bautista, Jorge Soria, Antonio Trenzado Romero, Cristina Elena Pérez-Jiménez, Amalia Ros-Santaella, José Luis Pintus, Eliana Bernardo, Nicola Comar, Mar Moreno-Rueda, Gregorio Oxidative stress Antioxidants Local environment Nestlings Blue tit Oxidative status has been proposed as an important ecological and evolutionary force given that pro-oxidant metabolites damage molecules, cells and tissues, with fitness consequences for organisms. Consequently, organisms usually face a trade-off between regulating their oxidative status and other physiological traits. However, environmental stressors and the availability of dietary-derived antioxidants vary according to local conditions and, thus, organisms inhabiting different habitats face different oxidative pressures. Still, there is little information on how different environmental conditions influence the oxidative status of animals inhabiting terrestrial environments. In this work, we examined the variation in oxidative status in the blue tit (Cyanistes caeruleus), a bird species with hatching asynchrony. Specifically, we examined the oxidative status of the largest and the smallest nestlings in the brood, inhabiting four forests differing in food availability and ectoparasite prevalence. We measured lipid peroxidation (malondialdehyde; MDA) as a marker of oxidative damage, total antioxidant capacity (Trolox-equivalent antioxidant capacity; TEAC) and antioxidant enzymatic activity (catalase, glutathione S-transferase, glutathione peroxidase) in blood samples. The glutathione peroxidase (GPX) activity differed among the forests, being the highest in the pine forest and the lowest in a mixed oak (Quercus) forest in the most humid area. Lipid peroxidation was higher in larger nestlings, suggesting higher oxidative damage with an increasing growth rate. Neither brood size, laying date, nor ectoparasites were related to the oxidative status of nestlings. These results suggest that nest rearing conditions might shape the oxidative status of birds, having consequences for habitat-dependent variation in regulation of oxidative status. 2025-01-28T09:10:48Z 2025-01-28T09:10:48Z 2021-08 journal article Garrido-Bautista J, Soria A, Trenzado CE, Pérez-Jiménez A, Ros-Santaella JL, Pintus E, Bernardo N, Comas M, Moreno-Rueda G. Oxidative status of blue tit nestlings varies with habitat and nestling size. 2021. Comp Biochem Physiol A Mol Integr Physiol. 258-110986. https://hdl.handle.net/10481/100675 doi.org/10.1016/j.cbpa.2021.110986 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Elsevier