Biology Reference
In-Depth Information
Table 8.4.
Mutual grooming among
Mauritian macaques.
#
%
F-J
72
47%
F-F
35
23%
J-J
26
17%
M-J
9
6%
F-M
7
5%
SAM-J
2
1%
SAM-M
1
0.05%
SAM-SAM
1
0.05%
Total
n = 153
100%
aggressive demeanor. Halfway through the study, Patch was injured (cause
unknown) and did not continue to participate in dominance interactions. After
this, Gorilla was harassed more by lower ranking males and by one immigrat-
ing male in particular. After a few weeks and while still dominant, he left the
group of his own volition. A younger adult male, #1, took over dominance. This
male had not been one of the males harassing Gorilla and, in fact, he had a very
calm, nonaggressive, permissive personality. Rank below the dominant, central
males was neither consistent nor stable. van Noordwijk and van Schaik (
2001
)
hypothesize that “transfer by males is a self-chosen option with a high prob-
ability of improving a male's reproductive opportunities” and that “males show
sophisticated assessment and decision-making.” We agree with this assessment
but would add that many factors seem to affect migration patterns at any given
time. Long-term studies of individual life histories would be needed to assess
how migration patterns relate to lifetime reproductive patterns.
It appears that the general social organization of these macaques is a rela-
tively fixed trait. However, particular patterns of social interaction, introdu-
cing variation around this theme, appear to be related to specific personalities
of individuals, to demographic conditions, to environmental conditions and
perturbations, and to interactions with humans. Unfortunately, unlike with
Japanese macaques and the introduced rhesus monkeys in Cayo Santiago,
Puerto Rico, there have been few long-term studies involving known geneal-
ogies for long-tailed macaques.
Activity cycles
At Mon Vallon, feeding was the most common macaque activity (30 per-
cent of observation time, with foraging an additional 2 percent) followed by
