92 Mountain Lions of the Black Hills
deer, to the contrary, are a more wary species when compared to mule deer, and white-
tailed deer occupied more open habitats, ponderosa pine forests, many of which had
been thinned by the USDA Forest Ser vice to promote tree growth and minimize dis-
ease (i.e., mountain pine beetle [Dendroctonus ponderosae] infestation). Thus, these
forests were relatively open and would promote visual identification of lions attempt-
ing to approach white- tails. In contrast, mule deer inhabited mountain mahogany
and juniper scrub habitats with dense ground cover. These habitats were located in
the foothills, where mule deer used established trails along hillsides. Use of these
trails likely promoted the stalking and attack of mule deer by mountain lions, because
of the close proximity between predator and prey (lions could hide in the thick
grasses adjacent to trails). Based on classic be hav ior, lions would pounce on the prey
and attempt to strangle it, either at the throat or by grasping the nasals or nose of the
deer. On a number of these carcasses, the nasals had been bitten and removed from
the facial area either during the attack or after the prey had been killed. This be hav-
ior seemed consistent for other large prey; I recall a mountain goat carcass found be-
tween Crazy Horse Mountain and Mount Rushmore north of Custer that had similar
characteristics to these preyed- upon deer. Once the prey was killed, the lion would
drag the carcass downslope into the thick vegetation at or near the bottom of a draw.
At times, we documented lions spending as long as four days at these sites, revisiting
the kills and covering the cached kills until most of the carcass had been consumed.
As indicated in table 6.5, mountain lions did kill white- tailed deer early in the re-
colonization of the region (or when the lion population was at low density), but data
collected at that time indicated that the kill rate of this species was likely low com-
pared to other prey. It was hypothesized that this predator that was new to the Black
Hills had to learn how to kill this new but ubiquitous prey species and that the learn-
ing curve might have been hastened by the lowered availability of “easy” prey (porcu-
pines) and the more limited availability of prey (mule deer, distributed mostly along
the perimeter of the Black Hills region) that mountain lions were skilled at killing.
Furthermore, there was that opportunistic character of mountain lions, which would
allow for unusual or rare prey to be taken just because it was in the wrong place at the
wrong time (for the prey) and was encountered. That might have been the case for a
gray jay (Perisoreus canadensis), an American mink (Neovison vison), and a yellow- bellied
marmot (Marmota flaviventris), all of which were documented during necropsy of
mountain lion carcasses as having been consumed. Because mountain lions spend time
in riparian zones dominated by white spruce (Picea glauca) during the daytime in
summer, small mammals such as southern red- backed voles (Myodes gapperi) also
have been consumed.
One historical factor occurring in the early years after 2000 that could be linked
with the transformation from easy- to- kill prey to predation on larger deer and elk was
that chronic wasting disease (CWD) was documented in captive elk in 1997–1998
(Jacques et al. 2003). In 2001 a free- ranging white- tailed deer that was harvested in