Proceedings of the Seventh Mountain Lion Workshop

DISPERSAL IN MALE PUMAS · Laundré and Hernández 155
Table 1. Average dispersal distances (km), home range sizes (HRS; km 2 ), and home range
diameters (HRD; km) of male pumas from various studies. The home range sizes are based on
resident males in the study areas. Dispersal distances are only of individuals who were known to
establish territories after dispersing or were at least > 24 months old before being killed.
Source n Distance H.R. Size HRD
Lindzey et al. (1989 & 1994) 4 142.2 731.0 30.5
Logan et al. (1986) 3 175.7 320.0 20.2
Spreadbury et al. (1996) 4 74.5 132.3 13.0
Hornocker (1960) &
Seidensticker et al. (1973)
5 102.4 379.5 22.0
Ashman et al. (1983) 6 48.9 355.2 21.3
Logan and Sweanor (2001) 13 128.2 187.1 15.4
This study 13 190.6 302.5 19.6
Averages 123.2 343.9 20.3
at least >24 months old at the time they were
killed (Sweanor et al. 2000). We found
dispersal distances for 48 male pumas from
7 different studies, including 13 estimates
from our study area (Table 1). We did not
use the dispersal distances reported by Beier
(1995) because his study area, although
large (2070 km 2 ), was completely
surrounded by urban development, which
limited dispersal opportunities. Dispersal
distances ranged from 31 km (Spreadbury et
al. 1996) to a maximum of 550 km (our
study). Estimates of resident home range
sizes of males in these studies varied
between 132.3 to 731 km 2 (Table 1). The
mean of these averages was 343.9 km 2 with
a HRD of 20.3 km. Dispersal distances
varied from 0.9 to 26 HRDs with a mean of
6.0 HRDs (Fig. 1). The majority (≈ 50 %)
of dispersal distances were between 2 and 4
HRDs with a second peak (25 %) between
8-9 HRD’s. There was a noticeable
reduction of dispersal settlements between 5
and 7 HRDs (Fig. 1).
Based on the individual estimates of
home range size, the frequency of HRDs
changed in some categories (Fig. 1).
However, the pattern was similar to the
distribution based on the overall average
HRD, e.g. the majority of the dispersal
PROCEEDINGS OF THE SEVENTH MOUNTAIN LION WORKSHOP
distances were between 2 and 4 HRDs. The
one difference was the appearance of more
settlements in the 5-7 HRD range (Fig. 1)
We found estimates of male mortality
rates from 4 other studies (Ashman et al.
1983, Ross and Jalkotzy 1992, Anderson et
al. 1992, Logan and Sweanor 2001) plus our
Figure 1. Frequency distribution of
dispersal distances, expressed as multiples
of the cross study average home range
diameter (HRD) and as multiples of the
individual study HRDs. The two curves
represent the expected frequency
distribution for the competition and the
inbreeding models.