Meeting Abstract
Invasive species can pose novel threats to native species they encounter. The red imported fire ant, Solenopsis invicta, is a novel predator and toxic prey of the eastern fence lizard, Sceloporus undulatus. Lizards from sites with long histories of fire ant invasion innately avoid eating fire ants, but increase consumption of fire ants with repeated exposure. If these lizards can distinguish fire ants from native ants, this would facilitate avoidance of this toxic invader, or utilization of this newly abundant food resource. We simultaneously presented fence lizards with four fire ants and four non-toxic native ants (Dorymyrmex bureni) and determined the numbers of individuals consumed or crushed without consumption. Overall, the lizards killed more of the native ants than the invasive fire ants, and they ate more of the native ants than they crushed, but consumed and crushed fire ants at similar frequencies. Increased activity rates of the native ants do not completely explain the greater frequencies at which they were killed. We investigate the possibility that differential nutritional value is driving the differences in consumption. Lizards may kill fire ants primarily to remove them as a predatory threat, but kill native ants for food. Our results suggest that lizards may be able to actually distinguish between ant species, opening the possibility for species-specific adaptive responses.
