|Vavra, Martin - OREGON STATE UNIVERSITY|
Submitted to: Annals of Arid Zone
Publication Type: Review Article
Publication Acceptance Date: September 4, 1998
Publication Date: N/A
Technical Abstract: An early focus on ungulate foraging behavior occurred in the 1940's as scientists began quantifying activities of livestock to address production goals. Interest resurfaced in the 1970's and continued as researchers pondered behavior related hypotheses at evolutionary, ecosystem, and plant/animal interface levels. Today, many grazing land concerns are related to the selective foraging habits of ungulates and their poor spatial distribution. The theories of optimum foraging and adaptive rumen function were offered to explain evolutionary patterns of forage selection among herbivores, but they lack the specificity needed by range and pasture managers at relevant space and time scales. Ungulates also exhibit selective patterns of spatial use about the landscape. In some environments where resources (water, shade, forage, minerals, escape topography or cover) are scarce, areas of activity are focused about these limiting elements. Many of the herding ungulates, however, repeatedly regraze areas and avoid other equally suitable portions of the landscape. Research suggests these habits elevate the animals nutritional status by curtailing advances in plant phenology and removing the hindrances of cured forage from grazed patches. Recent advances in geographic information systems and global positioning systems will facilitate analyses of animal behavior at landscape levels of resolution. Pasture and landscape managers are beginning to recognize many of the innate habits and preferences of livestock though, and are using these behaviors to affect succession, control weeds, and manipulate forage quality or structure of the community. There is much left to learn, but as we make inroads in these endeavors the value of grazing animals will increase.