Changes in Diet and Nutrition with Increased Herd Size in Texas White-Tailed Deer

Abstract

A high-density deer herd within a 3Yl-ha predator exclosure on the Welder Wildlife Refuge was sampled to investigate diet and nutritional levels. Annual diet of the exclosure herd averaged 76% forbs, 21% grasses, and 3% browse. Deer from the surrounding area consumed 87% forbs, 10% grasses, and 3% browse. Fawns from both herds consumed less grass during the first 9 months of life. The exclosure herd also exhibited lower ruminal levels of crude protein, higher levels of calcium, and higher calcium to phosphorus ratios than the surrounding herd. It was hypothesized that with increased herd size, deer within the predator exclosure overutilized the most desirable forb species and were forced to consume more grasses. The resulting decrease in nutritional level was responsible for changes in health, condition, and population parameters.

Drought but not population density influences dietary niche breadth in white‐tailed deer in a semiarid environment

“…We observed subtle differences, such as a slight, but statistically insignificant, increase in grass consumption and increased use of succulents during winter at high densities. However, we did not observe a shift from forbs to other forage classes such as occurred in response to increasing white-tailed deer density in studies by Kie et al (1980) and Daigle et al (2004).…”

“…For example, a two-fold increase in deer densities in southern Texas resulted in fewer herbaceous dicots in deer diets and increased graminoids (Kie et al 1980). In southern Quebec, deer from a high density (14 deer/km 2 ) population shifted their diet from forbs to greater prevalence of fruits, grasses, and farm crops compared to deer in a low density (1 deer/km 2 ) population (Daigle et al 2004).…”

A Review of Density Dependence in Populations of Large Mammals

“…Teer (1984) finds that ovulation is delayed, and both McCullough (1979) and Teer (1984) report delayed breeding seasons at higher densities for the species. Kie et al (1980) also indicate that under similar conditions, velvet is retained longer and the shedding of antlers is delayed. The Tule elk also shows changes in breeding season associated with density (McCullough, 1969).…”

“…Kie et al (1980) indicate that conception occurs later in the year for white-tailed deer at high population levels. Teer (1984) finds that ovulation is delayed, and both McCullough (1979) and Teer (1984) report delayed breeding seasons at higher densities for the species.…”

Winter plant selection by red and roe deer in a forest habitat in Hungary

“…Several studies have reported that diets of young animals did not differ from those of adults (Kie et al, 1980, Spinage et al, 1980. Eleven red and 10 roe deer rumen contents were sampled from pine plantations.…”