Biological consequences of winter‐feeding of mule deer in developed landscapes in Northern Utah

Abstract

Winter-feeding of mule deer (Odocoileus hemionus) in developed landscapes is often advocated by stakeholders to compensate for lost or fragmented winter range. However the reported benefits of winterfeeding mule deer to increase survival and productivity in altered landscapes are mixed. Few studies have examined the long-term effects of winter-feeding on mule deer productivity. We studied the effects of a winter-feeding program conducted in a developed landscape in northern Utah, USA from 2001 to 2006 on the productivity, survival, and mortality of 92 adult female deer (does) that were captured and radiocollared on 4 feed and 4 nonfeed sites. We also evaluated the potential for feeding programs to impact winter-range habitat quality through increased browse utilization. Fawn production (P ¼ 0.36), and survival (P ¼ 0.12) did not differ for fed and nonfed does. Deer-vehicle collisions were the primary cause of mortality for radiocollared deer in both populations (P ¼ 0.97). Utilization of desired browse species was higher on sites where deer were fed (P 0.001), although deer numbers were similar at feed and nonfeed sites. When developing big game winter-feeding policies for developed landscapes, managers must consider the full range of long-term potential population and habitat impacts to include increased anthropogenic-related mortality and increased potential for habitat degradation prior to policy implementation. ß 2011 The Wildlife Society.

To feed or not to feed? Evidence of the intended and unintended effects of feeding wild ungulates

“…This reduces the effects of density dependence (Lubow and Smith ), and population growth rates may increase (e.g., Ballesteros et al ) until a new higher carrying capacity is approached (Ozoga and Verme ). Although our findings supported this pattern (Table ), feeding programs also have the potential to decrease carrying capacity at high densities, either through negative impacts on summer or autumn forage availability (Ozoga and Verme ) or through an increase in year‐round use of limited winter ranges because of changes in migration patterns (Peterson and Messmer ).…”

“…Although many feeding programs, particularly in North America, state compensation for loss or fragmentation of natural winter range as their rationale (Smith , Peterson and Messmer ), few controlled studies ( n = 3) reported the effects of feeding on carrying capacity (Supplemental Material ). At the population level, we would expect that feeding increases nutritional carrying capacity and therefore population density, if other factors are not limiting (Brown and Cooper , Oro et al ).…”

“…When habitat requirements other than forage are limiting around feeding stations, animals may actually increase their movement and adjust their space use or habitat selection to meet those needs (Webb et al ). Although movement rates of white‐tailed deer and Angora goats ( Capra hircus ) did not change after being offered supplemental feed (Murden and Risenhoover ), moose using feeding stations moved more than non‐users (Mathisen et al ) and fed mule deer ( Odocoileus hemionus ) moved farther from bed sites to feed (Peterson and Messmer ). In Alpine areas, red deer that were fed in thermally unfavorable valley bottoms for practical reasons, moved daily to the better thermal conditions of high elevation meadows, whereas non‐supplemented herds remained in alpine meadows throughout winter (Schmidt ).…”

“…In studies addressing the increased probability of browsing or grazing impacts in response to feeding (4/4 studies; Table and Supplemental Material ), such effects were typically strongest in the immediate vicinity of feeding stations and weakened with increasing distance from feeding stations (van Beest et al ). Increased utilization (Peterson and Messmer ) or depletion (Cooper et al , van Beest et al ) of preferred natural forage species is commonly found in areas with feeding, with the extent being determined by feeding history, as well as the quantity and quality of the provided feed (Brown and Cooper , Kowalczyk et al ). Indeed, the area over which impact on the natural vegetation occurs can increase considerably with feeding program duration and may be sustained by re‐browsing for a number of years after feeding stations cease operating (van Beest et al ).…”

Winter supplementary feeding influences forest soil seed banks and vegetation

“…). Additionally, plant species preferred as forage are more intensively used in the vicinity of the feeding sites (Peterson & Messmer ), which eventually may locally lead to their depletion (Cooper et al. ; van Beest et al.…”