Mountain Lions of the Black Hills

62 Mountain Lions of the Black Hills

These early, large home ranges were in part a function of the area where we began
our work; however, initial estimates seemed to indicate that the home range sizes were
declining with increased population size. Jansen (2011) compared home ranges of male
and female lions captured in vari ous regions of the Black Hills. He found that both
males (804 km^2 ) and females (198 km^2 ) in the southwestern region of the Black Hills
had the largest home ranges, whereas males (315 km^2 ) in the northwest and south-
east and females (66 km^2 ) located in the northeast had the smallest home ranges.
Although he did not speculate on the potential reasons for these larger home ranges
in the southwestern region of the Black Hills, it is pos si ble that the distribution of the
prey base might be involved.
Early in our work with mountain lions, we also were investigating deer ecol ogy in
the southern Black Hills. As mentioned, we did not document mortalities associated
with lions in the north and central regions of the Black Hills; however, we did docu-
ment mortalities of deer, both white- tailed and mule deer, caused by lions in the south-
ern region. At the time, we had both white- tailed and mule deer radio- collared, and
data collected on mortalities suggested that coyotes (Canis latrans) were the primary
predator of white- tailed deer and that lions were focusing on mule deer. Because mule
deer occupied the brushy- scrub fringe of the Black Hills that also was characterized
by mountain mahogany (Cercocarpus montanus) and mountain juniper (Juniperus scopu-
lorum) (Simpson 2015), this habitat could have benefited lions when attempting
capture of mule deer. White- tailed deer were primarily found in open ponderosa pine
habitats, where it would be more difficult for lions to pursue and capture them.
Therefore, lions in the southwest might have had a more diverse prey base they were
attempting to prey upon; if so, that fact might have resulted in a need for larger areas
(Jansen 2011) to support successful capture of prey.
As with variability in home range size, overlap in territories between adjacent male
mountain lions varied considerably ( table 4.5). This variation (from 0 to 52%) was likely
due to a number of factors, including the distribution of female home ranges within
male territories, the number of females, the ages of adjacent males, the topographical
characteristics of home ranges, and the presence of transient males.

Table 4.5. Home range overlap (%) between 3 male mountain lions

Year

M1

M2

90%

M1

M2

60%

M1

M4

90%

M1

M4

60%

Total % overlap for M1

90% 60%

1999 5.1 0.0 12.8 0.0 1 7. 9 0.0
2000 15.3 2.3 36.7 20.2 52.0 22.0
2001 16.0 12.0 15.0 0.0 28.0 12.0
Average 12.1 4.8 21.5 6.7 32.6 11.3

Source: D. J. Thompson.

Note: Overlap zones were identified using 90% and 60% AK home ranges.