Geoscience Reference
In-Depth Information
Table 3.1
Simple Probability Index I
p
, Lloyd's Index I
L
, and Spearman's Rank
Correlation rfor Home Range Overlap of Adult Female Black Bears,
Wolves and Wolf Packs, and Stone Martens
Probability
index,
I
p
Lloyd's
Index,
I
L
Spearman's
r
Animal, Study Site
N
Mean ± SD
Mean ± SD
Mean ± SD
Wolves, Minnesota,
USA
Wolf packs
a
84
0.293 ± 0.484
0.34 ± 0.56
-0.013 ± 0.097
Wolves, different
packs
a
120
0.077 ± 0.150
0.37 ± 0.70
-0.784 ± 0.0174
Wolves, same pack
a
17
0.827 ± 0.087
2.84 ± 0.97
0.219 ± 0.447
Black bears,
USA
North Carolina
b
46
0.111 ± 0.169
0.40 ± 0.50
-0.722 ± 0.180
Northeastern
Minnesota
c
48
0.039 ± 0.076
0.20 ± 0.26
-0.828 ± 0.090
Stone martens, Italy
Same sex
d
11
0.018 ± 0.036
0.93 ± 1.28
-0.702 ± 0.219
-0.665 ± 0.277
-0.786 ± 0.144
Different sex
d
14
0.081 ± 0.106
3.79 ± 6.04
-0.558 ± 0.242
-0.480 ± 0.278
-0.806 ± 0.077
a
L. David Mech, personal communication;
b
Powell et al. 1997;
c
Rogers 1977;
d
Genovesi et al. 1997;
personal communication.
Overlap was calculated only for animals having overlapping or adjacent home ranges. Home ranges of
wolves in different packs and home ranges of wolf packs overlapped significantly less than did home
ranges of wolves in the same pack (
p
< 0.0001, general linear model [
GLM
], for each index). Home
ranges of adult female black bears in North Carolina overlapped significantly more than did those for
bears in Minnesota (
p
0.01,
GLM
, for each index). Home ranges of stone martens of the same sex over-
lapped significantly less than home ranges of martens of the opposite sex using
I
p
(
p
≤
≈
0.05,
GLM
) and
I
L
(
p
0.01,
GLM
), but not using Spearman's
r
.
N
is the total numbers of bears, wolves, packs, or martens
but not the sample size used in blocked statistical tests.
Under Spearman's
r
, the top figure in each row has been calculated on a 1-
≈
´
1-km grid, the second on
a 500-
´
500-m grid, and the third on a 125-
´
125-m grid.
Minnesota was caused by territory defense (Rogers 1977). No territorial
behavior was documented in North Carolina, but bears in both sites were sel-
dom seen by the researchers. Table 3.1 provides solid evidence for differences
in home range overlap and for differences in tolerance between individual
adult females at sites differing in productivity of food. The difference in home
range overlap between the two sites is consistent with observations of territo-
