Rotational grazing with cattle-free zones supports the coexistence of cattle and wild herbivores in African rangelands.
Abstract
African wildlife populations are declining at an alarming rate. To stop further population declines and restore ecosystems, more areas for wildlife are needed. Community-based conservation with wildlife-livestock coexistence in the vast rangelands of Africa presents a major opportunity. However, the efficacy of wildlife conservation in mixed land-use areas remains an outstanding question. To assess the ecological outcomes of land-sharing between regulated livestock herds and wildlife populations in African savannas, we test how rotational cattle grazing affects spatiotemporal dynamics of 15 large herbivore species in the Maasai Mara, Kenya. First, we tested how wild herbivore distributions across the Greater Mara Ecosystem (the Mara, ~2600 km2) are related to cattle density and environmental variables using 584,561 observations of wild herbivores (ecosystem scale). In a second analysis, we tested how rotational cattle grazing affects wild herbivore distributions in a 300 km2 subsection of the Mara using 30,583 observations (landscape scale). Finally, we tested how functional traits of wild herbivores affect species-level spatiotemporal responses to cattle grazing. At the ecosystem scale, the presence of five wild herbivore species was positively correlated with cattle density, while cattle effects on wild herbivore abundances were species-dependent with both increases and decreases. At the landscape scale, rotational cattle grazing strongly impacted the spatiotemporal habitat selection of wild herbivores, resulting in distinct lag periods with which different species are attracted to areas previously grazed by cattle. These lag periods were linked to functional traits, with body mass and herd size explaining 35% of the interspecific differences. Small to medium-sized herbivores with large herds select areas recently grazed by cattle, whereas large species with large herd sizes and small species with small herd sizes avoid recently grazed areas. Synthesis and applications: Our results revealed that the effect of cattle on wild herbivores varies considerably among species, suggesting that cattle-wildlife interactions range from facilitation to competition. To maintain species that strongly avoid cattle, designated livestock-free zones remain essential, also in rotational grazing systems. Rotational grazing systems with regulated livestock densities present an important opportunity to better manage wildlife-livestock coexistence and thus improve wildlife conservation in African rangelands.