Mountain Lions of the Black Hills

86 Mountain Lions of the Black Hills

5 years, especially for males, which possibly reflects the costs of holding and main-
taining territories. TKFI for females, although less variable than for males, surely re-
flects the costs of reproduction. For example, despite 13 years of age, one female had
relatively high fat levels, suggesting that sufficient food was available for fat storage,
even though the body weight of this individual had declined.
When looking across time, we did document some variation in average TKFI lev-
els that occurred after 2005–2006, when the population was believed to be saturated
(fig. 6.7). Means for males and females were closely associated with each other prior
to this year and subsequently became disjunct, with females averaging generally lower
fat reserves; this was the period linked to cloudy- eye disease in some lions. Interest-
ingly, mean percentages for TKFI for males and females became closely associated
again in 2013, after the population had been reduced from saturation levels by har-
vest. At that time, expectations were that prey availability would have increased
per individual lion. Because fewer males would be moving and competing for territo-
ries, and sufficient prey was available to support these fat reserves, female reproductive
effort might have become more stable as well, although the effects of kitten mortal-
ity through infanticide also could contribute to these values.
As can be seen, studying a species over a long term allows for an understanding of
changes affecting individuals and populations temporally. We were able to follow this
population from just after colonization, or from a low population size, to what we be-
lieve was population saturation, to a reduced population size owing to a manipulated

700

600

500

400

Total kidney fat inde

x

300

200

100

0

0246

Age

810

female

male

12

figure 6.6. Relationship between total kidney fat index and age and sex of

mountain lions from the Black Hills.