EXPLOITING HETEROGENEITY - HABITAT USE IN CATTLE IN DRYLAND ZIMBABWE

Savanna landscape in the dry communal areas of southern Zimbabwe are h ighly spatially heterogenous. This year-long study explores the respon ses 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 herbace ous biomass per unit area in the dry season and in dry years in both s avanna types. Browse is available in all habitats, but particularly wh ere there is a low understorey of shrub vegetation. Cattle feeding pat terns respond to this heterogeneity of available fodder at the landsca pe level. Studies of foraging behaviour demonstrate that cattle show h igh levels of seasonal feeding preference for particular parts of the landscape, notably low lying 'key resource' habitat types with high le vels of available herbaceous biomass. Cattle foraging strategies (thro ugh free grazing or herding) involve both concentration on these key r esource areas and switching between a variety of habitats and forage s ources, including browse. These strategies differe both between savann a types and seasons of the year. Planning for livestock management in the dry areas of Zimbabwe should take into account the importance of l andscape heterogeneity in the design of grazing interventions. Policie s also need to ensure that flexible movement responses to a highly spa tially and temporally variable resource base are possible.