1. Foraging strategies and physiological status of a marine top predator differ during breeding stages
- Author
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Petra Quillfeldt, R. Colominas-Ciuró, L. Michel, Marco Cianchetti-Benedetti, Giacomo Dell'Omo, German Research Foundation, and Ministerio de Economía y Competitividad (España)
- Subjects
Male ,Physiology ,media_common.quotation_subject ,Foraging ,Foraging strategies ,Zoology ,Oxidative phosphorylation ,Biology ,Breeding ,medicine.disease_cause ,Biochemistry ,Models, Biological ,Birds ,medicine ,Leukocytes ,Life-history stages ,Animals ,Molecular Biology ,Incubation ,Apex predator ,media_common ,Trophic level ,Reproduction ,Metabolism ,Feeding Behavior ,Oxidative Stress ,VeDBA ,Scopoli's shearwater ,Predatory Behavior ,Linear Models ,Female ,Oxidative status ,Energy Metabolism ,Oxidative stress - Abstract
Habitat characteristics determine the presence and distribution of trophic resources shaping seabirds' behavioural responses which may result in physiological consequences. Such physiological consequences in relation to foraging strategies of different life-history stages have been little studied in the wild. Thus, we aim to assess differences in oxidative status, condition (fat stores, i.e. triglyceride levels, TRI), stress (Heterophil/Lymphocyte (H/L) ratio), and leukocyte profiles between incubation and chick rearing highlighting the role of foraging strategies in a seabird (Calonectris diomedea). Chick rearing was more energetically demanding and stressful than incubation as demonstrated by high stress levels (H/L ratio and leukocytes) and lower body stores (assessed by TRI and the increment of weight) due to the high energy requirements of rearing chicks. Also, our results make reconsider the simplistic trade-off model where reproduction increases metabolism and consequently the rate of oxidative stress. In fact, high energy expenditure (VeDBA) during chick rearing was correlated with low levels of oxidative damage likely due to mechanisms at the level of mitochondrial inner membranes (uncoupling proteins or low levels of oxygen partial pressure). Further (more distant) and longer (more days) foraging trips were performed during incubation, when antioxidants showed low levels compared to chick rearing due to incubation fasting, a change in diet, or a combination of these factors; but unlikely because of oxidative shielding since no relation was found between oxidative damage and antioxidant capacity. Males showed higher numbers of monocytes which were positively correlated with antioxidant capacity compared to females, suggesting sexual differences in immune profiles. Species-specific costs and energetic demands of different breeding phases trigger behavioural and physiological adjustments., This study was funded by Deutsche Forschungsgemeinschaft (grant QU148/17-1). In addition, RCC received financial aid from an FPI and a mobility grant from the Spanish Ministry of Economy and Competitiveness (grants BES2012-059299 and EEBB-I-16-11566).
- Published
- 2021