Regan Berkley is a regional wildlife biologist for Idaho Fish and Game's Magic Valley region, which includes the Wood River Valley.
By REGAN BERKLEY
As winter approaches, so does the inevitable dialogue over elk feeding in the Wood River Valley. Before the discussions over feeding begin anew this winter, we'd like to provide some important and relevant facts about elk biology that may help inform the conversation.
Though elk have always lived in the Wood River Valley, their numbers dwindled during the settlement boom of the late 19th and early 20th centuries. To boost numbers, elk from Yellowstone National Park were relocated to the Wood River Valley between 1935 and 1937 and regulations were enacted to protect them from over-harvest by hunters. The elk population of the Wood River Valley has grown significantly since then, and the Idaho Department of Fish and Game estimates that over 3,000 elk spend a significant part of their year within the Wood River drainages. It is the department's goal to manage wild elk numbers at a level that existing natural winter habitat can sustain to provide a harvestable surplus for hunters and for the enjoyment of all Idahoans.
Most populations of elk migrate between high-elevation summer habitats and lower-elevation winter habitats. These movements help elk avoid the deep snow that makes movement and foraging difficult. Although the distances of these migratory movements vary, elk can move up to 50 miles between traditional summer and winter habitats.
Winter is typically a difficult time for elk. Migration requires significant energy expenditure, and occurs not long after breeding season, another energy-demanding time. Furthermore, though winter ranges provide benefits in the form of more easily accessible forage and less energy-expensive movement, the nutritive value of forage on winter range is typically marginal at best. During winter, elk engage in a process of controlled starvation, by which they expend as little energy and ingest as much forage as possible until new green growth appears in the spring.
Luckily, elk are physiologically well-adapted to the nutritional deficiencies that winter brings. Their coats provide good insulation, and they generally enter winter with fat reserves that help stave off the winter decline. However, over-winter survival is still dependent on several factors: elk condition prior to winter, snow depth, temperatures, winter duration and availability of winter forage.
Winter losses to malnutrition can comprise a major source of annual mortality. Studies have shown that it is not uncommon for 30 percent of calves to die during a normal winter. Adult bulls, whose pre-winter energy reserves are compromised by the rut, can also experience high winter mortality. Adult cows typically carry the highest fat reserves into the winter and consequently survive better than bulls or calves. As winter severity increases, elk mortality also increases.
Winter range is typically considered the annual "bottleneck" for elk populations; that is, overall elk numbers are primarily dependent on the quality and quantity of winter habitat. Although it is heart-wrenching to watch an elk struggling to avoid starvation at the end of a long winter, these deaths are part of a natural cycle. Winter mortality is how nature maintains the balance between available habitat and the elk that depend upon it. Without winter mortality, herds may exceed the habitat's capacity to support them, resulting in more winter starvation, lower birth rates and lower summer and fall survival of calves. Furthermore, habitat may be degraded and can take years to improve. Elk herds often suffer in the interim.
Historically, the Wood River Valley and surrounding foothills provided winter habitat for many of the elk that spent their summers in nearby mountains. As development has accelerated, much of this available winter range has been lost. Well-meaning citizens have tried to compensate for the loss of winter range by feeding elk in the Wood River Valley. Unfortunately, winter feeding is not a panacea, and bears with it many problems, including habitat degradation, increased potential for the spread of disease, damage to landscaping and the attraction of predators. For these and other reasons, we discourage winter feeding of elk and urge concerned citizens to grant wild elk the dignity of carving out the living to which they are adapted, in a difficult, but natural, landscape.
