Document Type


Journal/Book Title

Global Livestock Collaborative Research Support Program


University of California at Davis

Publication Date



Drought regularly affects rangelands and contributes to high death rates for livestock and poverty for pastoralists. But do livestock losses occur randomly simply when rainfall is low, or are they cyclical and predictable? Previously, PARIMA researchers proposed that high stocking rates—combined with low rainfall—trigger livestock die-offs on the Borana Plateau. It takes about six years for animal numbers to recover, setting the stage for another die-off when a dry year occurs. This “boom-and-bust” cycle is based on observed herd crashes in 1983-5, 1991-3, and 1998-9. Researchers predicted in 2002 that the next major die-off would occur during 2004-06, and one goal of this brief is to report on recent observations. Team members also examined ecological change in relation to livestock patterns. Results confirm that a major crash occurred during 2005, verifying the prediction. The rangelands have been degraded by decades of heavy livestock grazing, resulting in bush encroachment and top-soil erosion. Will the next livestock crash occur “on schedule” around 2011? Probably not—it is expected sooner. Researchers speculate that the production system is rapidly changing, a view shared by local pastoralists. Livestock carrying capacity is reportedly declining and animal die-offs may become more frequent and irregular.