Exploiting heterogeneity:habitat use by cattle in dryland Zimbabwe

Savanna landscapes in the dry communal areas of southern Zimbabwe are highlyspatially heterogeneous. This year-long study explores the responses of cattle to variation in the availability of fodder in different habitat types situated in clay and sandy soil savanna zones. Low land habitat types of relatively small overall area, such as drainage lines, riverine strips and dambos, have the highest availability of herbaceous biomass per unit area in the dry season and in dry years in both savanna types. Browse is available in all habitats, but particularly where there is a low understorey of shrub vegetation. Cattle feeding patterns respond to this heterogeneity of available fodder at the landscape level. Studies of foraging behaviour demonstrate that cattle show high levels of seasonal feeding preference for particular parts of the landscape, notably low lying ‘key resource’ habitat types with high levels of available herbaceous biomass. Cattle foraging strategies (through free grazing or herding) involve both concentration on these key resource areas and switching between a variety of habitats and forage sources, including browse. These strategies differ both between savanna types and seasons of the year. Planning for livestock management in the dry areas of Zimbabwe should take into account the importance of landscape heterogeneity in the design of grazing interventions. Policies also need to ensure that flexible movement responses to a highly spatially and temporally variable resource base are possible