Modeling tiger population and territory dynamics using an agent-based approach

Effective conservation planning of globally endangered tigers (. Panthera tigris) requires a good understanding of their population dynamics. Territoriality, an essential characteristic of many wildlife species, plays a crucial role in the population dynamics of tigers. However, previous models of tiger population dynamics have not adequately incorporated territoriality. We therefore developed and implemented a spatially explicit agent-based model of tiger population dynamics shaped by different territorial behaviors of males and females. To allow for predictions to new conditions, for which no data exist, territories are not imposed but emerge from the tigers' perception of habitat quality and from their interactions with each other. Tiger population dynamics is deduced from merging territory dynamics with observed demographic rates. We apply the model to Nepal's Chitwan National Park, part of a global biodiversity hotspot and home to a large (~125) population of tigers. Our model matched closely with observed patterns of the real tiger population in the park, including reproduction, mortality, dispersal, resource selection, male and female land tenure, territory size and spatial distribution, and tiger population size and age structure. The ultimate purpose of the model, which will be presented in follow-up work, is to explore human-tiger interactions and assess threats to tiger populations across contexts and scales. The model can thus be used to better inform decision makers on how to conserve tigers under uncertain and changing future conditions.