Integrating habitat and population dynamics to uncover dispersal-driven persistence in a reintroduced Crested Ibis...

Metapopulation theory explains species persistence through dispersal-linked populations. This study links theory and conservation to predict reintroduction success in human-altered landscapes. Using the Crested Ibis (Nipponia nippon) as a model system, we combined spatially explicit habitat modeling with stochastic population viability analysis to assess how dispersal mediates persistence across wild and reintroduced populations in a metapopulation context. Our integrated approach identified 15,216 km^² of potential habitat and a 95.64 km least-cost pathway linking wild population and reintroduced population. Projections over 50-year simulations revealed that dispersal significantly enhanced metapopulation viability, enabling population size to reach 17,846 individuals (92.37 % of carrying capacity). Conversely, population isolation would lead to a 15% decline in reintroduced population. Our simulations demonstrated that environmental stressors (including catastrophic events and predation pressure) reduced overall metapopulation size by 61.8% and 22.7% respectively when dispersal was absent. However, active dispersal effectively mitigated these impacts, maintaining long-term quasi-extinction probabilities at 0.17. The analysis revealed a clear source-sink dynamic, with the wild population serving as a stable source population, while the reintroduced population remained dependent on metapopulation connectivity for persistence.