Tolerance to Dietary Phenolics and Diet Breadth in Three Seed-eating Birds: Implications for Graminivory

作者：Manuel Rios Juan; Marcelo Mangione Antonio; Marone Luis

来源：Journal of Experimental Zoology Part A-Ecological Genetics and Physiology, 2012, 317A(7): 425-433.

DOI：10.1002/jez.1735

The ability to cope with plant secondary compounds (PSCs) has profound implications for an animal%26apos;s behavior. In the present study, we assessed the tolerance to dietary phenolics in three seed-eating birds: Zonotrichia capensis, Saltatricula multicolor, and Diuca diuca, which differ in their diet breadth. Seeds in their habitat have distinct chemical composition: grass seeds have less PSCs, specifically, less total phenolics than forb seeds. Based on the detoxification limitation hypothesis and using published data of the natural history of these birds in the central Monte desert, we postulate that predominantly and exclusively graminivorous birds such as D. diuca and S. multicolor, respectively, are less tolerant due, in part, to a lower detoxification capacity than those with greater diet breadth, Z. capensis. To achieve this goal, we measured the food intake of diets varying in their concentration of tannic acid (TA). Indicators of tolerance were body mass change, food, TA and water intake, and glucuronic acid output throughout the experiment. Zonotrichia capensis performed better along the tolerance experiment: it maintained body mass from 0 to 4% TA diet, food and TA intake were higher than the other two species at the end of the experiment, and glucuronic acid output by Z. capensis was greater than D. diuca and S. multicolor from 2% TA diet until the end of the experiment. Our results suggest that Z. capensis is the most tolerant species and this physiological trait may explain their greater diet breadth. J. Exp. Zool. 00A:1-9, 2012.

• 出版日期2012-8