Contraction of their historic geographic ranges and conflicts with humans underpins declines in large carnivore populations worldwide. These declines, which characterize pastoral systems where carnivores, people and livestock live in close contact, may be paralleled by changes in carnivore behaviour. We investigated this by comparing the behaviour, demography and space-use of three lion (Panthera leo) prides in the protected Masai Mara National Reserve and the adjoining Koyiaki pastoral ranch in southwestern Kenya during 2005–2006. The mean times lions were inactive was similar between the three prides except when the ranch lions were severely disturbed and became more nocturnal and inactive. The reserve lions ate their kills on open plains and returned to them often but the ranch lions did so only inside bushes and abandoned unfinished kills during a drought in 2005. The reserve lions spent most of their time on open plains while the ranch lions did so in bushes and woodlands. Activity budgets were similar between the prides regardless of land use. Adult lions altered not so much the type but the spatial location and timing of their behaviour on the pastoral ranches relative to the reserve. We discuss the implications of these findings for lion conservation on pastoral lands.