| Roosevelt elk tend to have low reproductive rates, which may be linked to low forage quality in the dense, wet coniferous forests in the Pacific Northwest. Managers have attempted to increase productivity by planting high-quality pasture plants. Therefore, I examined the biomass and nutritional quality of forage fields planted and maintained by Washington Department of Fish and Wildlife for Roosevelt elk on the Olympic Peninsula in relation to natural forages produced by the surrounding forest. I also examined home range and habitat selection of radiocollared elk residing near and away from the forage fields, and the composition and nutritional quality of diets they selected. Pasture forages (orchard grass and clover) planted in the forage fields provided more digestible energy and protein and a greater biomass of nutritious forages than the native forbs, ferns, and shrubs found in the surrounding forests. The fields produced enough high-quality forages to support about 100 elk year-round. Elk residing near the fields used a home range only half the size of those that used the forest away from the fields. When selecting a home range on the landscape, both field and control elk selected riparian and open coniferous habitats, but within their home ranges, elk selected forage fields. Elk consumed mostly shrubs, ferns and grasses year-round, and diet composition was similar between control and field elk, except in spring. Orchard grass and clover averaged < 5% of elk diets seasonally. Although the control elk ate a slightly more nutritious diet, the predicted digestibility was insufficient for reproduction in elk.; Populations of mule deer have also declined over the last 2 decades in northeastern Washington. Because Se deficiencies that can reduce reproduction are common in livestock in these areas, I examined the blood Se levels of mule deer across this region. Although blood Se varied widely, most animals were deficient to marginal relative to livestock standards. The highest mean Se concentrations were found in deer from north and western parts of the study area, which have the lowest soil and plant Se. Mule deer may have access to Se supplements offered to livestock in these areas. |
