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Pogonomyrmex californicus, invasive species, seed preference, coastal sage scrub, grassland, foraging, Claytonia perfoliata, Eschscholzia californica, Bernard Field Station


European grasses, such as B. diandrus and B. madritensus, have disturbed California environments by outcompeting the native coastal sage scrub, which is endemic to the coastal areas of Southern California and Northern Mexico. Here, we sought to determine if P. californicus, Harvester ants, have a preference for native seeds or nonnative seeds and if that preference changed depending on the location of the Harvester ant nest, in invasive grassland or native coastal sage scrub. Previous research has shown that the Harvester ant species P. rugosus show a preference for exotic seeds over native seeds. Likewise, we predicted that Harvester ants would show a preference for nonnative Eschscholzia californica seeds over native Claytonia perfoliata seeds in both the coastal sage scrub habitat and grassland habitat. We did not find evidence to support our hypothesis, as the Harvester ants showed a significant preference for native seeds over the nonnative seeds in both habitats.