Speaker
Description
Turtle populations are unique among animals in their extreme life history strategy: they are long-lived, with adult mortality due largely to human intervention. In contrast, juveniles have extremely low survival rates, mainly due to predation. Practically, this has led to difficultly in re-introducing populations of turtles into historically viable ecosystems. We develop a model of freshwater turtle population dynamics in the context of generalist predation. The model explores the sensitivity of populations to adult mortality. We show that the model allows for a saddle-node bifurcation in adult mortality, elucidating that once a population is driven out of an area, it cannot easily be re-introduced. Furthermore, analysis of a Lyapunov function for the system highlights the structural issues of "headstarting" programs that aim to seed turtle populations with manual introduction of juvenile turtles.
