Disease Ecol ogy of Mountain Lions 69Because there was no information available to answer this question, we began a
study funded through the South Dakota Department of Game, Fish and Parks to collect
brain tissue from hunter- harvested deer and elk to test for the presence of the disease
(Jacques et al. 2003). Heads of legally harvested deer and elk from throughout South
Dakota were transported to the laboratories of the South Dakota Department of Game,
Fish and Parks in Rapid City and the SDSU laboratories in Brookings, and brain tissue
samples were collected and sent to the Diagnostic Laboratory at Iowa State University
to test for the disease. This study provided evidence that the disease was pres ent in
free- ranging deer but only in the same area as where those captive elk were located
(Jacques et al. 2003) and in very low prevalence; thus, statements associating the dis-
ease with captive elk were supported. These findings also established the need to collect
information on other diseases potentially affecting large mammals in the region.
One study that included a focus on disease dealt principally with the effects of fire
on the nutritional condition of white- tailed and mule deer in the southern Black Hills
(Zimmerman 2004). The student who carried out the study, Teresa (Zimmerman)
Frink, was intensely interested in diseases and, because of this interest, dedicated part
of her thesis to this topic. We also knew that some deer in this region were dying
because of predation by mountain lions. The deer study involved the removal of adult
females for necropsy and sample collection. During these collections we obtained in-
formation on external and internal parasites as well as exposure to diseases docu-
mented by blood serum samples (Zimmerman 2004). One in ter est ing finding was the
presence of the parasite Taenia omissa in mule deer (fig. 5.1). The parasite requires an
intermediate host and generally passes between predators and prey species. Predators
carry the parasite, which is dispersed within the environment via feces. Prey, such as
mule deer, ingest the parasite when consuming vegetation. Taenia omissa is considered
a core species within the distribution of mountain lions (Waid and Pence 1988), and
the presence of the parasite within mule deer from 2002 to 2003 provided additional
support for an active predator- prey relationship between the two species early in our
studies of mountain lions. This same relationship was documented with the recent
presence of mountain lions in Manitoba (Dare and Watkins 2012).
In the late 1990s, when we began our work, those first mountain lions captured
appeared healthy, based on external coat, teeth characteristics, and body weights. This
relatively good health was supported by necropsy of mortalities, which included col-
lared as well as noncollared cats. Also, as mentioned, males had few scars that would
indicate intrasexual battles over territories as had been documented in other studies
(Maehr 1997; Logan and Sweanor 2001). However, as the population increased in size
from 1999 to 2005, we began seeing potential issues with the health of mountain lions
in the Black Hills.
One of the most notable changes was first observed in the southern Black Hills and
involved what we called cloudy- eye syndrome (fig. 5.2), a corneal opacity caused by