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.

No abstract

Grass production was monitored based on seasonal harvests under various canopy covers of h&ache on a Coastal Prairie blackland range site during 1978 and 1979. Grass production (Y) was not decreased in 1978, compared to that on essentially brushfree areas, until huisache canopy cover (X) exceeded 30% based on the reiationship, Y = 2,346 -I-20X -0.62X*. Texas wintergrass standing crop apparently increased as huisache canopy cover increased to 25% and its growth during winter partly compensated for standing crop losses of warm season species during the winter. In 1979, the contribution of the cool-season species was masked by greater production of warm-season species. Consequently, grass production decreased with increasing huisache canopy cover according to the relationship, Y = 4,047 -14.9X -0.29X2. Based on the functional relationship Y = a -blX-bzX*, coefficients of determinations (P) ranged from 0.50 to 0.96 when estimates of annual production of grasses or production for the growing season only were regressed against huisache canopy cover.

No abstract

No abstract