Chimpanzees of the Budongo Forest : Ecology, Behaviour, and Conservation

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Effects of snare injuries on feeding and social life 177

two-handed or foot-and-hand grasps (Stokes and Byrne 2001: 23). In such ways do our
Sonso chimpanzees that have had the misfortune to get snare injuries compensate for
their disabilities and succeed, with great fortitude, in feeding themselves. The alternative
is death from starvation, and we do not know how many chimpanzees, having extricated
themselves from snares, either die of gangrene or other infections, or fail to adjust to the
new situation and eventually die.
The effects of disablement on the social lives of Sonso chimpanzees was first studied
by Quiatt et al. (1994). They noted that disabled individuals were nevertheless fully
integrated socially and there was no evident discrimination against them by able-bodied
individuals.
A wide-ranging and very detailed study of the effects of snare injuries on the Sonso
chimpanzees is that of Munn (2003, in press). Munn found a number of hitherto unex-
pected differences between injured and uninjured individuals. Her study focused on the
females of the Sonso community, and examined the effects of both snare- and trap-related
injuries, looking at the ways injury affects social behaviour, mother–infant behaviour
and locomotion.
Munn studied 12 females, all mothers with dependant infants, of which 5 were
injured and 7 were uninjured, the latter being the control group. (The whole community
consisted at the time of 49 individuals; all adult females were studied.)
In regard to social factors, Munn found that, compared with the uninjured females,
injured females spent more time in small, family and nursery groups, and less time in
the larger mixed and sexual groups (groups with oestrous females in them), as can be
seen from Fig. 9.7. This was true whatever activities they were engaged in, i.e. resting,
feeding or travelling. Family and nursery groups are in general quieter and more


0
Family Nursery
Type of group

Mixed

Injured
Non-injured

Sexual

5

10

15

20

Percentage of scans

25

30

35

40

Fig. 9.7: Percentage of time spent by injured and non-injured chimpanzees in various group types
(from Munn 2003).

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