Seed removal by birds, rodents and ants in the Austral portion of the Monte Desert, Argentina

The relative importance of granivory by birds, rodents and ants in the southern Monte Desert (Argentina) was examined using an experimental seed–dish technique. Monthly seed-removal rates were recorded during two consecutive years, from September’ 1995 to August’ 1997. Birds were the main and most constant seed eaters during the study period. There was no seed removal by ants in September’ 95, April, June, and July’ 96, and May, June and August’ 97. There was no consumption by rodents from March to May’ 96. Rodents consumed significantly more seeds than did ants during both winters, and springʹ 96. Conversely, seed removal by ants was significantly higher than that of rodents in summer 96. Overall removal rates were significantly different between both annual cycles studied. The highest seed-removal rate was recorded in March 1997. We compare our results with those obtained by several authors at the northern and central Monte Desert, as well as other arid and semi-arid regions of the World, reevaluating conclusion about granivory in South American arid zones.