Pathways for Positive Cattle–Wildlife Interactions in Semiarid Rangelands

Livestock- wildlife interactions in rangelands are often viewed in terms of competition, but livestock and native ungulates can also benefi t each other through long- term modifi cations of rangeland habitats. Here we synthesize research on rangelands in central Laikipia focusing on two types of cattle- wildlife interactions that have implica- tions for their long- term coexistence. The fi rst interaction occurs via redistribution of soil nutrients within the ecosystem, which is a consequence of the use of bomas (temporary corrals) to manage livestock. Our studies on two different soil types show that rotational boma management creates hectare- scale patches in the landscape that are enriched in soil and plant nutrients and persist for decades to centuries. In both of the predominant soil types in Laikipia, forage phosphorus content is low relative to ungulate demands during peak lactation. Nutrient- rich boma sites (hereafter referred to as glades) provide a key wet- season forage resource of nutritional suffi ciency for lactation. Our studies further show that a wide range of native ungulates selectively use glades relative to surrounding nutrient- poor habitats. Impala (Aepyceros melampus) in particular show intensive use of glades on sandy soils and are rare in portions of the landscape lacking glades. A second important pathway for cattle- wildlife interaction occurs through the infl uence of native browsing ungulates on woody vegetation. Shrub and tree cover has been increasing in Laikipia over the past century, followed by increases in native browsers in recent decades on ranches where wildlife are allowed to coexist with cattle. Our exclosure experiments in central Laikipia indicate that native browsers suppress shrub encroachment on both dominant soil types. However, the strength of browser effects are three to seven times greater on sandy soils, where two browsers, dik- dik and elephants, are both abundant, compared to heavy clay soils, where elephants are the only dominant browser. In the clay soils, native browsers still exert a signifi cant infl uence on dynamics of the domi- nant tree, Acacia drepanolobium, and suppress encroachment by subdominant shrub species. Browser effects on woody vegetation likely enhance forage production for cattle and maintain open habitats favored by native grazers for predator avoidance. Taken together, our studies indicate that boma rotation and browser control of shrub encroach- ment are key interaction pathways that promote cattle- wildlife coexistence in the Ewaso ecosystem.