Mountain Lions of the Black Hills

82 Mountain Lions of the Black Hills

older than about 26 weeks. However, that would be expected, because as kittens aged,
we fed complete diets for felids obtained from zoos, and also fresh chicken. These
captive kittens gained 0.67 (±0.03) kg per week, significantly more than wild kittens,
which gained 0.57 (±0.05) kg per week. Furthermore, using only kittens that max-
imized growth, the predicted weight gain (r^2 = 0.99) was 0.73 (±0.02) kg per
week, which could represent the maximum weight gain for mountain lion kittens
under ideal conditions. In fact, based on this model, the maximum weight of dispers-
ing mountain lions would range between 35.3 kg (79.1 lbs.) and 39.67 kg (88.9 lbs.),
which was comparable to the actual weights of 12 to 14 month old male lions leaving
the Black Hills.
Male and female weights (n = 239 lions) plateaued around 1 to 3 years for females
and 3 to 5 years for males (fig. 6.3). The weights of lions that were established were
generally around 40 kg (88 lbs.) for females and 60 kg (130 lbs.) for males. For males,
these weights were above those of dispersing animals (38 kg [84 lbs.]) and indicated
that they had gained weight after establishing territories. The maximum weights of
males surpassed 72 kg (158 lbs.), while females varied from about 40 kg after estab-
lishing a home range to about 50 kg (110 lbs.) when pregnant. Male growth rates were
2.6 times those of females, whereas female growth rates were about 22% more vari-
able than those of males.
We did notice some senescence with a 13- year- old female that weighed 39 kg
(fig. 6.3). However, a female aged at 9–10 years when it was collared later successfully
raised a litter, indicating that, given sufficient prey, the species can continue to con-

90

80

70

60

Body mass (k

g)

50

40

30

20

10

0

0246

Age

81012

female

male

14

figure 6.3. Body weights of male and female mountain lions (aged to 13 years) from
the Black Hills.