THE EFFECTS OF INVASIVE PREY ON NATIVE PREDATORS
Open Access
- Author:
- Venable, Cameron
- Graduate Program:
- Biology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- February 28, 2019
- Committee Members:
- Tracy Langkilde, Dissertation Advisor/Co-Advisor
Stephen Wade Schaeffer, Committee Chair/Co-Chair
Rudolf Johannes Schilder, Committee Member
Nancy Ostiguy, Committee Member
Nancy Ostiguy, Outside Member - Keywords:
- Invasive Species
Behavior
Learning
Lizards
Fire ants
Cue detection - Abstract:
- Invasive species can be competitors, predators, and prey of native species. I used a system of the native eastern fence lizards (Sceloporous undulatus), an invasive prey, the red imported fire ant (Solenopsis invicta), and a native prey, pyramid ants (Dorymyrmex bureni), to test how native predators behaviorally respond to invasive prey. Juveniles consumed similar numbers of native and invasive ants whereas adults consumed nearly three times as many native ants as invasive fire ants. This shift towards increased consumption of fire ants in adulthood could be the result of lifetime experience. However, the preference may be a culmination of other causes, as adult lizards do not seem to use chemical cues to differentiate these species, but instead encounter more of the native species in controlled experiments and when given the option to consume or reject ants, they reject invasive ants three times more than native ants. Juvenile lizards can rapidly learn to avoid eating toxic fire ants, but resume consuming these ants after a few days if their initial exposure level was low. Learned avoidance of fire ants carried over to native ants, with lizards that had eaten (and learned to avoid) invasive fire ants reducing subsequent consumption of a palatable native ants. This could limit the prey pool of this species, which predominantly eats ants. Together my dissertation research provides insight into how native species can adapt to novel prey in their environment, and potential consequences of such adaptation. Future work should explore the potential community level consequences of adaptive responses to invasive prey.