Lizard Eggs and Ants

A trade-off between dominance and resource discovery may promote species coexistence, yet evidence from natural systems remains limited. We tested this using a field experiment on two ants: the dominant Paratrechina longicornis and the exploiting Pheidole taivanensis, competing for lizard eggs. When P. longicornis encountered eggs occupied by P. taivanensis for 1 day, it displaced them. However, after 2 days, it ignored the eggs because P. taivanensis had damaged the shells, reducing resource value. At Sandimen, lower resource use led to shorter exploitation time, but higher ant density increased displacement rates. These results suggest lizard eggs are ephemeral resources used both spatially and temporally, and support a context-dependent trade-off between resource discovery and dominance.