To a high degree, both wild and domestic herbivores are creatures of habit, and they typically choose to occupy only small portions of the entire landscape that is available to them. In extensive rangeland settings, intensively used areas may be associated with the presence of scarce but necessary resources like water, shade, hiding cover, or mineral sources, and animals will center their activities about those areas. One problem associated with these uneven patterns of distribution is that preferred forages in some areas may endure repeated and eventually detrimental use, while similar forages in many unused areas may never be grazed. A positive aspect of this, however, is that on a landscape basis, a greater diversity of plants and animals may occur where patches of grazed and ungrazed vegetation co-exist.
The inexpensive forages of rangeland pastures have the capacity to support many more animals if the herbivores can be lured into previously unused areas. Historically, water developments, fencing, herders, and mineral supplements have been used to encourage or discourage livestock grazing on rangelands. These are costly and occasionally prohibited methods of influencing livestock distribution in extensive settings, and less expensive and more environmentally sensitive techniques are needed to manipulate livestock dispersal patterns.
To assist with this problem several studies have been designed to more thoroughly understand which plant, animal, and landscape features most heavily influence livestock grazing behavior. At the plant level we have found that beef cattle can be extremely selective foragers, extracting as much as 80 percent of their diet from only 3 percent of the forage base. Cattle are also quite aware of standing-dead stems in their forages, and they prefer to use plants or areas that require little if any sorting of old and new growth.
Presently GPS collars and GIS software are being used to investigate spatial patterns of beef cattle distribution at landscape levels. Effects of salt and water manipulations are currently being researched, and the influences of previous grazing history of the landscape and the spatial patterns of forage quality will be studied in the near future.
If you are interested in these projects, contact Dave Ganskopp.