Litter and seed burying alter food availability and foraging efficiency of granivorous birds in the Monte desert.

• Autores: Cueto, Victor; Milesi, Fernando Adrian; Marone, Luis
• Año de publicación: 2013
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Foraging Behavior; Microhabitat Structure; Granivory
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

We assessed experimentally if the main granivorous bird species that feed on the ground in the central Monte desert are able to detect and consume seeds buried in the soil or trapped within litter. Understanding seed vulnerability to birds allows 1) a better understanding of how seed abundance translates into seed availability, a necessary step to assess seed limitation scenarios, and 2) whether birds alter the distribution of soil seeds through their consumption. Rufous-collared parrows found and consumed high proportions of buried seeds, though less seeds were eaten at increasing depths. In contrast, many-colored chaco-finches, common diuca-finches and cinnamon warbling-finches did not find buried seeds. All bird species fed on every substrate offered but, as a whole, birds reduced by 50% their seed consumption in Prosopis litter, and by 30% in Larrea litter, compared to consumption in bare soil. This effect was less notable for rufous-collared sparrows, whose ‘double scratch’ foraging method would contribute to its great diet breath and abundance in the Monte desert. As birds do not reach a fraction of seeds buried and trapped by litter, seeds readily available for them may be scarcer than previously estimated through soil seed bank studies. Furthermore, since the four bird species detect and consume seeds from littered microhabitats, seed consumption by them surely affects the seasonal dynamics of the soil seed bank in all microhabitat types of the Monte desert.
Fil: Cueto, Victor. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina
Fil: Milesi, Fernando Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentina
Fil: Marone, Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mendoza. Instituto Argentino de Investigaciones de Zonas Aridas; Argentina