Harvester Ant Foraging and Shrub-Steppe Seeds: Interactions of Seed Resources and Seed Use

摘要: Granivore—seed interactions involve a feedback between granivore seed selectivity and availability. We examined this to determine how preferences by the western harvester ant, Pogonomyrmex occidentalis, related availability and, in turn, affected soil pool. Preferences were estimated from natural diets as well experiments that controlled size, relative availability, distance ant nests. Seed ants varied with season over 2 yr. Colony activity intake rates correlated preference was seasonal of preferred species, but not unpreferred seeds. From pool, preferentially harvested small, sound They removed 9—26% potentially viable pool each year, much 100% available species. densities lower 2—7 m nests, where foraging concentrated, than 7—12 In contr...