Demographic drivers of a refugee species: large-scale experiments guide strategies for reintroductions of hirola

Effective reintroduction strategies require accurate estimates of vital rates and the factors that influence them. We estimated vital rates of hirola (Beatragus hunteri) populations exposed to varying levels of predation and rangeland quality from 2012 to 2015, and then built population matrices to estimate the finite rate of population change (λ) and demographic sensitivities. Mean survival for all age classes and population growth was highest in the low predation/high-rangeland quality setting (λ = 1.08 ± 0.03 SE), and lowest in the high predation/low-rangeland quality setting (λ = 0.70 ± 0.22 SE). Retrospective demographic analyses revealed that increased fecundity (the number of female calves born to adult females annually) and calf survival were responsible for higher population growth where large carnivores were absent. In contrast, variation in adult survival was the primary contributor to differences in population growth attributable to rangeland quality. Our analyses suggest th...