Detoxification and energy costs in consequence of phenolic secondary compounds consumption on two passerines with different food habits

BARCELÓ GONZALO; JUAN MANUEL RÍOS; PABLO SABAT

Québec

Simposio; Colloque en science de la biodiversité 2014 / 2014 Symposium on biodiversity science; 2014

Le Centre de la Science de la Biodiversité du Québec (CSBQ),

Chemical composition of the food and the breadth of the diet are closely related to physiology and the ability to metabolize nutrients. Although seed-eating birds have a high nutritional food, they face the challenge of dealing with variable amounts of secondary compounds (SC). We postulate that the detoxification capacity of a bird is associated with a high cost due the organs responisble of this process, liver and kidney, contribute significantly to energy metabolism. To test this hypothesis, we analyzed the effect of sub-chronic consumption of SC by two species of the Emberizoidea superfamily with different dietary habits: the omnivorous Zonotrichia capensis and the granivorous Diuca. Three contrasting diets were prepared: a control diet, a diet with 2% of tannic acid, and a diet added with Opuntia ficus-indica extract. After 5 weeks of exposure to the diets, we found that analyses for energy-digestive variables account for differential responses between Z. capensis and D. diuca. In both species, detoxification capacity expressed as glucuronic acid excretion was higher in individuals who consumed diets enriched with phenols compared to the control diet, however, higher values in Z. capensis were presented. Also Z. capensis showed an increase in basal metabolic rate in the group fed with diets enriched with phenols compared to the control. Interspecific differences in response to phenols intake would be determined by the ecological context. While both species can cope with moderate phenols diets, energy costs.