Successful seed-based restoration in dryland systems is difficult due to the many limitations associated with germination and establishment. Seed predators, including granivorous ants, can consume or move applied seeds offsite reducing restoration success. Granivorous ants in the U.S. southwest move and store tens of thousands of seeds and show preferences for seeds based on weight, size, nutrient content, and novelty. In this study, we examine which seed traits most influence seed predation rates in a grassland in southwestern Arizona, U.S.A. We presented 24 seed types from native species with restoration value in three cafeteria-style selection areas installed adjacent to Pogonomyrmex nests. We also installed pitfall traps to assess the diversity of ant species that may have visited the cafeterias. Our results showed that among offered seeds, 3-99% were collected by granivorous ants, with small seeds and those with no structure the most preferred. Across all cafeterias, we had 11 ant species in our pitfall traps, with over half of those being known seed predators. From our study, we found that seed traits do influence ant seed preference and our results can help inform practices that could aid in keeping seed on the ground and increasing the chance of germination and establishment.

No abstract