SUMMER BED SITES OF ELK (CERVUS-ELAPHUS) IN THE BLACK-HILLS, SOUTH-DAKOTA - CONSIDERATIONS FOR THERMAL COVER MANAGEMENT

The characterized 131 summer, diurnal bed sites of 26 elk (11 bulls an d 15 cows) in Custer State Park, South Dakota, from 5 June-30 August 1 994, 1995 and 1996. Overstory canopy closure, number and basal area of trees, percent litter and bare ground were greater (P < 0.05) at bed sites than at random plots. North aspects were selected (P < 0.05). Mi crosite air temperature and percent of grass were lower (P < 0.05)at b ed sites than at random plots. Hiding cover, wind speed, percent of fo rbs, shrubs, rocks, and wood, slope percent, average tree dbh, elevati on, distance to roads, distance to trails, and distance to water were not different between bed sites and random plots (P > 0.05). Trees wer e present at 128/131 (97.7%) of bed sites (0.01 ha square plot), but o ccurred on only 41.2% (54/131) of random plots. An average summer, diu rnal elk bed site had basal area >12.4 m(2)/ha, >110 trees/ha, >54% ca nopy closure on N aspects. Overstory canopy closure, tree basal area a nd microsite temperature correctly classified 86.2% of the observation s, suggesting thermoregulatory factors influenced CSP elk use of summe r, diurnal bed sites. Although elk are successful in some unforested a reas despite the lack of suitable thermal cover, our data suggest that elk in the Black Hills prefer relief sites that provide thermal bed s ites when available during the summer diurnal period. Management of ap propriate thermal cover should be maintained in areas in which it exis ts.