Proceedings of the Seventh Mountain Lion Workshop

Sweanor 2001) could easily dominate over
their smaller mother or sisters. As males do
not seem reluctant to mate with close
relatives, i.e. daughters, why don’t they wait
around to mate with their sisters or mothers?
We conclude that the only logical answer to
this question is that the high level of conflict
with their fathers or, by default, even more
competitive older bigger new male arrivals
(who have displaced their fathers), force
young males to disperse out of their natal
area at an age (13-15 months of age) before
they are sexually mature (Sweanor 1990).
Regarding prediction #3, the observed
frequency distribution of HRDs was best fit
by the competition model with a p(0) = 0
and an increasing p(x) until a distance of 5
HRDs. This model would reflect the effect
of an increasing competitive ability of the
young males as they disperse. In contrast, it
is obvious that the data do not fit the most
critical part of the inbreeding avoidance
model: males should not settle within 2
HRDs of their natal home range.
Additionally, considering that even 5 HRDs
may not be sufficient to reduce the chance of
inbreeding with sisters (Shields 1987,
Sweanor 1990), the high percent (>50%) of
settlements within the first 4 HRDs argues
strongly against inbreeding avoidance being
the driving force behind male dispersal.
The decreasing number of settlements
between 5 and 7 HRDs likely reflects the
fragmented nature of the 2 studies that
contributed the majority of the data (54.2 %;
Logan and Sweanor 2001 and this study). In
both studies, the principal mountain range(s)
of the study areas are separated from nearby
larger mountain ranges (places young pumas
are most likely to find vacant territories) by
valleys 75 to 100 + km wide. Thus, there is
a reduced likelihood of a male puma finding
a territory in the 5-7 HRD range.
Although neither model predicted the
higher number of settlements we found at >9
and up to 20 HRDs, this finding also does
DISPERSAL IN MALE PUMAS · Laundré and Hernández 157
PROCEEDINGS OF THE SEVENTH MOUNTAIN LION WORKSHOP
not support the inbreeding avoidance
hypothesis. If a young male was dispersing
primarily to avoid inbreeding, we would not
predict such long distance dispersals where
animals passed up what would appear to be
ample suitable habitat in their dispersal
movements. The only explanation for such
long distance dispersals is they had to
continue to travel because they were outcompeted
by resident males or transients
that had traveled further than themselves.
Eventually, they would gain weight and
experience enough to successfully compete
for a territory (Sweanor 1990).
Sweanor (1990) originally suggested that
male residency times, the polygynous
mating system, and male dispersal distances
in pumas argued against inbreeding
avoidance being the main driving force in
dispersal of young male pumas. However,
after presenting further evidence of
aggression among male pumas and
inbreeding between fathers and daughters,
Logan and Sweanor (2001) concluded that
inbreeding avoidance was likely the main
driving force behind male puma dispersal.
Their argument centered on the assumption
that young males should only disperse far
enough to “avoid” competition. We contend
that with 15 - 18 % of puma populations
being primarily transient males (Hemker et
al. 1984, Ross and Jalkotzy 1992,
Spreadbury et al. 1996, Laundré and Clark
2003), no dispersing male ever has the
luxury of avoiding competition for a
territory. They concurred with the presence
of these transients and observed that new
males were constantly coming into their
population and concluded from this that
competition must be “tolerable”. They
further argued that under the competition
hypothesis, however, most of the male
recruits in their growing population should
have been offspring of the area. Because in
their study most male recruits came from
outside, they argued that this refuted the