Effects of Habitat Enrichment on Patterns of Diet Selection

Abstract

Foraging theory predicts that animals should feed more selectively in response to an increased abundance of high-quality foods. We tested these predictions by examining changes in patterns of diet selection by white-tailed deer (Odocoileus virginianus) and Angora goats (Capri hircus) in response to habitat enrichment. When a high-quality supplement was provided ad libitum, both species responded by increasing foraging effort and by feeding more selectively on natural forages. Supplemented animals consumed a greater proportion of plants containing high concentrations of crude protein (CP) and digestible energy (DE), which resulted in an increase in average diet quality. Responses of individual deer and goats varied and appeared to be related to differences in habitat heterogeneity between trial enclosures. Our results suggest that supplementation may be disruptive to normal behavioral processes affecting the distribution of free-ranging herbivores on the landscape. These processes may be important in reducing the probability of excessive utilization of palatable forage species, and to the competitive relationships between range plants.

Effects of desertification on the body temperature, activity and water turnover of Angora goats

“…The higher activity levels on the intact site may be explained by foraging theory, which predicts that animals should feed more selectively when high-quality foods are more abundant (Stephens and Krebs, 1986). Indeed, Angora goats fed more selectively on natural forage, thus increasing their foraging effort and movement rates by nearly 70%, when given a high-quality supplement (Murden and Risenhoover, 1993). Similarly, sheep spent a greater portion of time grazing on pastures which had high levels of soluble carbohydrates (Birrell, 1989), which are abundant in succulent species, such as P. afra, as a result of their crassulacean acid metabolism (Borland et al, 2009).…”

Effect of supplemental feeding on spatial distribution and browse utilization by white-tailed deer in semi-arid rangeland

“…It is well known that deer given supplemental feed continue to browse the local vegetation (Mautz, 1978;Verme and Ullrey, 1984;Schmitz, 1990;Murden and Risenhoover, 1993). The pattern of browsing on the arrays of seedlings around the feeders indicates that deers do not come to the feeders, eat their fill, then leave; rather they browse while in the vicinity of the feeder.…”

“…They also increase their diet selection by concentrating on the higher quality forage species (Murden and Risenhoover, 1993). These high-quality forage plants are often uncommon in the habitat.…”

Can the impact of deer browsing on tree regeneration be mitigated by shelterwood cutting and strip clearcutting?

“…4A and B). The availability of high-quality forage was found to affect the selection patterns and foraging behaviour of white-tailed deer (Murden and Risenhoover, 1993;Berteaux et al, 1998;Coulombe et al, 2008). In our study, it is possible that the limited establishment of new white birch seedlings together with high deer densities prevented any significant changes in diet selection by white-tailed deer.…”

“…This is important because white birch is highquality winter forage for white-tailed deer (Crawford, 1982;Dumont et al, 2005). Some studies have pointed out that whitetailed deer fed more selectively in response to an increased abundance of high-quality foods (Murden and Risenhoover, 1993;Berteaux et al, 1998). If browsing is concentrated on preferred species, the pressure on balsam fir may be reduced and some individuals could grow beyond the reach of deer.…”