Spencer A. Cortwright, Indiana University Northwest
Most predator-prey systems feature interacting species that express vastly different life cycles and autecologies. For example, predators are likely longer-lived and in larger populations than are prey. However, intraguild predators and prey often have, for example, similar longevity and population sizes. Studies on dynamics of such interactions can yield insights into persistence of intraguild predators and prey. Jefferson salamanders (Ambystoma jeffersonianum) and spotted salamanders (Ambystoma maculatum) are intraguild predators and prey, respectively, during their larval stage. Long-term population studies in southern Indiana show that sites where spotted salamanders colonized simultaneously with Jefferson salamanders were able to grow large spotted salamander (prey) populations and now persist via episodic reproductive bouts when larval Jefferson salamander populations dip. Sites where Jefferson salamanders colonized earlier and developed large populations have kept later colonizing spotted salamanders on a slow population growth track. Thus, timing of colonization (or in other cases recolonization) can have an important impact on intraguild predator-prey dynamics.