Data from: 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 that hirola demography is driven by a
combination of top-down (predation) and bottom-up (rangeland quality)
forces, with populations in the contemporary geographic range impacted
strongly by declining rangeland quality. To enhance the chances of
successful reintroductions, conservationists can consider rangeland
restoration to boost both the survival and fecundity of adult females
within the hirola’s historical range.