162 Intra-community killing — the case of Zesta
a tooth during the attack, the right humerus shows five tooth scrapes and there are bite
scrapes on the bones of the right hand. These were serious bites indeed.
Interpretation
How can these highly unusual events be explained? We can follow the points made by
Fawcett and Muhumuza (2000) in their interpretation.
First, it was clear from the extent of the injuries to Zesta (ZT) that several chim-
panzees were involved in the attack, and they were members of the Sonso community.
This meshed with the fact that three of the Sonso males had new wounds including the
alpha male Duane (DN) and the gamma male Black (BK). (The beta male (VN) was not
present, as far as we know.) The third male to show wounds was Andy (AY) and it is not
clear how this came about. He was smaller and younger than ZT and may perhaps have
tried to defend him, or become accidentally involved in the initial fighting. The fact that
this attack occurred in the core of the Sonso community range also indicates that it was
a ‘domestic’ fight and did not involve extra-community chimpanzees.
ZT was the youngest and lowest ranking of the adult males, he had never attempted
to usurp power, and so this was clearly not an attack by senior males on a rival, not a
political attack or a result of a power struggle.
Food was plentiful at the time, and it was not considered that feeding competition had
any part to play in the attack.
Mating competition provides a possible avenue of explanation. At the time of the
attack there was only one female in oestrus in the community, Janie (JN), and she was
in maximal tumescence. At this time, there were 12 mature males in the community,
all competing for this one female. Other than JN, none of the 13 adult females was
in oestrus, and all had infants. There was thus intense competition for access to JN.
From previous records of copulation and grooming events, ZT was the most frequent
copulation and grooming partner of JN. As Fawcett and Muhumuza write:
It is hypothesized that a preferential relationship between Zesta and Janie, and the presence of
Janie in maximal tumescence, may have both instigated and escalated the violence of the attack.
We suggest that Zesta, a young adult male, may not have observed his position within the male
hierarchy, and thus became the target of aggression.They point out that at Mahale, the ostracism and eventual attack on a young adult
male (non-lethal, the male escaped) was also interpreted to be the result of inappropriate
social behaviour (Nishida et al. 1995), as described earlier in this chapter. Comparing
the two cases, we can note the underlying excitement of meat-eating in the Mahale case,
suggesting that what underlay the case of ZT may have been sexual excitement centred
on JN. Why the case of ZT escalated whereas Jilba was able to escape may be related to
the presence of BK in ZT’s case. BK was a very aggressive male. He was gamma male
in the hierarchy but was at that time trying hard to rise to beta place. He had for some
time been unsuccessfully competing with the beta male Vernon (VN), and had attempted