POPULATION VIABILITY ANALYSIS OF THE FLORIDA GRASSHOPPER SPARROW (AMMODRAMUS SAVANNARUM FLORIDANUS): TESTING RECOVERY GOALS AND MANAGEMENT OPTIONS

We developed a spatially explicit population-viability-analysis (PVA) model to evaluate different management options for the endangered Florida Grasshopper Sparrow (Ammodramus savannarum floridanus). We also conducted a sensitivity analysis to determine which parameters had the greatest effect on population viability. The model was most sensitive to environmental variation and least sensitive to carrying capacity, initial abundance, and level of correlation in demographic rates between subpopulations. The model that represented present conditions predicted a 22% chance that the population will fall below the extinction threshold of 60 male Florida Grasshopper Sparrows within 50 years. Reintroduction to large prairie sites and prairie restoration reduced the chance of falling below the extinction threshold and increased the number of subpopulations occupied. Loss of dry prairie located on private land adjacent to existing Florida Grasshopper Sparrow subpopulations increased the probability of fall...