A generalized stochastic birth/death population model based on Indian RiverLagoon dolphins

For over a decade, researchers at Harbor Branch Oceanographic Institute (HBOI)
have conducted surveys of the bottlenose dolphin (Tursiops truncatus) population of
Indian River Lagoon (IRL) in Florida. I have constructed a 4-stage population model
using the statistical program R. The model is used to conduct a viability analysis by
analyzing the relationship between birth, calf and adult survival rates. The power
analysis compares survey frequency to expected confidence intervals in estimating
abundance. The sensitivity analysis shows that the population is most sensitive to
changes in adult survival, followed by birth rate and calf survival. The model shows a
strong chance of viability over a 50 year time span. The population is vulnerable to long
periods of decline if birth, calf or adult survival rates fall below certain thresholds.
Overall, the model simulates the future impacts of demographic change, providing a tool
for conservation efforts.