Trophic ecology of the Ringed Warbling-Finch (Poospiza torquata) in Neotropical semi-arid scrublands

SÁNCHEZ R; BLENDINGER PG

EMU

CSIRO PUBLISHING

Lugar: Collingwood; Año: 2014 vol. 114 p. 229 - 233

0158-4197

Abstract. Seed-eating birds living in temperate deserts must cope with striking variation in food resources. We studied the trophic ecology of Ringed Warbling-Finches in semi-arid scrublands of the Monte desert, Argentina. Based on variations in seed availability, we assessed seasonality in consumption of arthropods and seeds at a regional scale, and evaluated the composition and breadth of the granivorous fraction of diet. Ringed Warbling-Finches have a granivorous-insectivorous diet that is largely based on arthropods in summer and on seeds and arthropods in winter. The granivorous fraction of the diet consisted mainly of grasses with a low breadth of the winter seed diet. To deal with seasonal food variation, the species switches opportunistically to diets based on different resource channels, exploiting alternating patterns of food abundance. This seasonal switch is a well established strategy in the behaviour of the species and was observed in all Ringed Warbling-Finch populations studied across the Monte desert. These data demonstrate the flexibility on foraging strategies of Ringed Warbling-Finches, an opportunist that adjust their relative consumption of seeds and arthropods in response to the spatial and temporal variations in food resources.