Abstract
Conserving core habitat is a widely employed, but rarely evaluated, management strategy to benefit species and broader levels of biodiversity. Yet, few researchers have rigorously evaluated core area management's effectiveness in improving demographic parameters, especially in Central Asia, where the global cashmere trade—which incentivizes massive livestock increases and environmental degradation—threatens 70% of the region's large mammals. In a 12‐year study, we used a before–after field manipulation of livestock densities in a 71‐km 2 core zone of critical wildlife habitat in the 660‐km 2 Ikh Nart Nature Reserve in Mongolia. Inside the core area, we reduced livestock from 1200 to 700 head (40% reduction) out of Ikh Nart Nature Reserve's total 56,640 head (0.9% reduction). The core zone encapsulated critical habitat for argali ( Ovis ammon ), the world's largest wild sheep, including key lambing areas. Accounting for yearly environmental variation, livestock reduction increased argali neonatal birth mass by 17%, increased annual juvenile survival from 18% to 50%, and increased annual population growth from 0.91 to 1.00. Where livestock are abundant, reducing habitat degradation in even small areas of key habitat can positively affect wildlife at low cost to local livelihoods. Our investigation offers empirical evidence that livestock detrimentally affect native ungulates and supports the critical role of core conservation areas and local pastoralists in conservation.