Individualistic herds: Individual variation in herbivore foraging behavior and application to rangeland management

Rangeland systems cover vast areas of the earth's surface containing great diversity of life, and contribute to the livelihoods and welfare of millions of people. The management of rangeland systems for ecological and commercial outcomes is driven by a need to understand how grazing animals achieve most efficient and sustainable use of resources within the landscape. This process is multi-faceted; however, advances in understanding how foraging animals form decisions in complex landscapes offers strong potential for enabling rangeland managers to predict, and manage, the grazing distribution of large herbivores. Recently, there have been increasing calls to incorporate variation in individual behavior to enhance management of grazing distributions across resources or landscapes. However, widespread adoption of this approach has not occurred. Here, we review the roles of morphology, physiology, experience, and environmental and social conditions in driving differences in individual foraging behavior in large herbivores, and how these individual differences can be maintained within wild populations. We then synthesise this knowledge to examine if viable opportunities for exploiting individual differences in the behavior of livestock exist. We conclude by identifying remaining important challenges and areas for future research to facilitate using individual variation in foraging behavior to manage grazing patterns in rangeland systems. (C) 2009 Elsevier B.V. All rights reserved.