Ecol ogy of the Black Hills 25cover for prey also provides stalking cover for mountain lions (Logan and Sweanor
2000). For example, in the Black Hills, we observed a mountain lion stalking white-
tailed deer using dense chokecherry (Prunus virginiana) shrubs for concealment; the
chokecherry bushes provided the same herd of deer a food source, especially in win-
ter. We have also located both radio- collared mountain lions and one uncollared
mountain lion in dense white spruce (Picea glauca) stands (Fecske 2003). We hypoth-
esized that the animals were using the cool, moist stands for concealment cover, ther-
moregulation during hot weather (Jalkotzy, Ross, and Wierzchowski 1999), and
stalking cover, since white- tailed deer in the Black Hills are known to select mixed
white spruce stands during summer (DePerno 1998).
Dense vegetation also is used by mountain lions for concealment and security cover
while feeding and as nursery sites by female mountain lions (Logan and Sweanor
2000); in the Black Hills dense vegetation often occurs along drainages (Klaver et al.
2008) (fig. 2.10). Steep slopes, boulder piles, undercut cliffs, and rock outcrops serve
mountain lions much as vegetation does. In turn, rugged terrain is impor tant to
ungulates seasonally, as exposed south- and west- facing slopes provide food and mild
weather conditions in winter (Logan and Sweanor 2000). In the northern Black Hills,
north- facing slopes also provide these same benefits for deer (Kennedy 1992). Logan
and Irwin (1985) suggested that density estimates of mountain lions obtained from
areas with specific habitat features could be used to estimate breeding population
densities in areas with similar habitat. Home ranges also have been used to determine
density estimates of large carnivores (Clark, Dunn, and Smith 1993). We used our
habitat- relation model to identify high- quality habitat to predict mountain lion occur-
rence. In addition, in conjunction with data collected from a sample of radio- collared
mountain lions, the lit er a ture, and a mountain lion population program (Program
PUMA; Beier 1993), we were able to generate an initial population estimate for the
region (Fecske 2003). Our projected population indicated that more than 100 moun-
tain lions could be occupying the Black Hills, but when I presented these results at
a regional meeting, my suggestion met with considerable objections from the audience;
in fact, many in the audience responded with disbelief.
Seasonal temperature fluctuations in the Black Hills are characteristic of the con-
tinental climate that is typical of the region (Orr 1959). Mean annual temperatures
range from 5°C to 9°C with extremes of −40°C to −44°C. Mean annual precipitation
is greater than 66 cm (Orr 1959), and annual snowfall can exceed 254 cm at higher
elevations (Thilenius 1972); snow in the southern regions of the Black Hills is unpre-
dictable and rarely lasts more than a few days. The region is known to receive late
winter storms with significant snowfall. In fact, migrating whitetails have died during
these storms, likely owing to lack of forage and increased susceptibility to predators
(DePerno et al. 2000). Relative to climate, the Black Hills can be separated into
northern and southern regions (Froiland 1990). The northern area is characterized
by colder temperatures, deeper snows, and higher precipitation, whereas the southern