Oxidative status during reproduction in Magellanic penguins (Spheniscus magellanicus): incubation versus chick rearing.

COLOMINAS-CIURÓ R.; CARABAJAL E.; D'AMICO V.L.; BERTELLOTTI M.; BARBOSA A.

Cracow

Simposio; ICCPB 2015: The 9th International Congress of Comparative Physiology and Biochemistry; 2015

Magellanic penguins (Spheniscus magellanicus) breed colonially coinciding with improved environmental conditions. Their breeding cycle is formed by various periods (courtship and nest building, incubation, guard phase and crèche) which require different energy allocation. Energy release is directly related with oxidative balance. Our aim therefore is to examine whether oxidative status in blood plasma (total plasma antioxidant capacity, oxidant components and total non-protein thiol groups) differs between incubation and the guard phase. Magellanic penguins perform longer foraging trips during the incubation than during the guard phase probably in response to energy loss during pre-incubation activities. Therefore, we expect that oxidative status was higher in the former than in the latter. Fieldwork was conducted in a Magellanic penguin colony located in Estancia San Lorenzo (42⁰ 05?S, 63⁰ 49?W), Peninsula Valdes, Argentina. All penguins sampled were nesting under shrubs incubating two eggs or rearing two chicks (to avoid uneven parental efforts). Our results support the expectations as adults in incubation present significantly lower antioxidant values for the total plasma antioxidant capacity and for the total non-protein thiol groups. In contrast, oxidant components did not show significant differences between both breeding periods. We did not find differences in oxidative status between sexes. In addition, adults present a significant greater weight during incubation which could be related with a higher foraging activity in this stage for self-maintenance.