Mathematical Modeling in Ecology: Simulating the Reintroduction of the Extinct Passenger Pigeon (Ectopistes migratorius)

The Passenger Pigeon (Ectopistes migratorius) was an iconic species of bird in eastern North America that comprised 25-40% of North American avifauna. Passenger Pigeons went extinct in 1914 due to excessive hunting over the previous 50 years. Current research aims to de-extinct the Passenger Pigeon and someday release the species into its historic range. To determine under which conditions a Passenger Pigeon could survive a reintroduction into a natural habitat, we used two types of models. First, we used a system of delay differential equations to explore the relationship between the young pigeon, adult pigeon, nest predator, and raptor populations. The model incorporates logistic population growth, an Allee effect, and a Holling Type III functional response. Next, we developed a spatially explicit, agent-based model to simulate the population dynamics of the Passenger Pigeon in a number of present-day forest environments. The model incorporates the following stochastic processes: varying availability of food sources, reproduction, and natural death of the Passenger Pigeon. Bio-energetics, tree distributions, and other ecological values were obtained from literature. Results from our simulations suggest that the Passenger Pigeon could survive a reintroduction into a natural environment.