Small translocations of endangered Gallinula galeata sandvicensis (Hawaiian Common Gallinule) may be sufficient to generate a viable reintroduced population.

This article focuses on evaluating translocation strategies for the endangered Hawaiian Common Gallinule (Gallinula galeata sandvicensis, also known as 'alae 'ula) to establish new populations while minimizing risks to existing source populations. Using updated demographic data and stochastic population viability analysis (PVA) with the software Vortex, the study modeled translocations from three wild source populations on O'ahu and Kaua'i to a hypothetical recipient site with a carrying capacity of 50 individuals. Results indicate that gradual translocations of at least 20–30 after-hatch-year birds spread over multiple years reduce extinction risk for both introduced and donor populations compared to bulk translocations, though removing large numbers from the smallest source population (Hamakua Marsh) increases its extinction risk. Sensitivity analyses identified juvenile mortality and brood size as critical factors influencing reintroduction success, with juvenile survival rates near thresholds for population failure, underscoring the importance of post-release management such as predator control and habitat quality. The study recommends sourcing individuals from multiple genetically distinct subpopulations to reduce inbreeding risk and selecting sufficiently large recipient wetlands (estimated 3.75–74.6 hectares) to support viable populations.