Summarizing, the existence of female dominance interactions confirmed that some
degree of female–female competition exists, and it is hierarchical, though Fawcett could
not construct a full-scale hierarchy (as was possible for Newton-Fisher in his study of the
males) because so many female–female pairs were not seen involved in any dominance
interactions at all. Length of residence and age were important factors and they inter-
acted with each other: all adult females were dominant over all subadult females.
However, within the adult females age was not necessarily correlated with dominance as
some younger females such as Kwera and Kewaya, by virtue of having been in residence
for very many years, were dominant over some older females who had immigrated.
Bethell (1998, 2003) looked at rank relationships in both males and females in a novel
way, by studying social monitoring, or ‘vigilance’ which she documented by counting
the number of times individuals looked at each other in parties. She found that both
males and females monitored their social environment but in different ways. For lower
ranking individuals of either sex, vigilance was directed to higher ranking individuals.
Lower ranking males spent time looking at higher ranking males, and lower ranking
females spent time looking at both higher ranking females and males. The need for
vigilance in lower ranking individuals meant that they were only secondarily able to
focus on potential mates and attend to reproductive strategies. In contrast, high ranking
individuals could concentrate on reproductive strategies without fear of interventions
such as threats or attacks. This was borne out by the fact that Duane, the alpha male,
spent nearly a quarter of the time he was being observed looking at females, more than
any other male. Dominant females, on the other hand, spent significantly more time
looking at food sources than lower ranking females.
Vocalizations
The basic set of vocalizations of chimpanzees was described by Reynolds and Reynolds
(1965). Goodall (1986) listed 34 calls, grouped into 13 different emotions or feelings
with which they are associated (Table 6.4). These emotions or feelings are expressed in
social situations and the different calls give information to others in the group, either
about the context (e.g. the ‘Wraaa’ sound indicates fear and directs the attention of
others to anything strange in the vicinity), or the rank order (the ‘pant-grunt’ indicates
subordinacy), or enjoyment of good food (the ‘pant-hoots’ of chimpanzees, which often
occur in choruses of many individuals calling together, can indicate the presence of
good food in a single tree or an area of forest). There are many variations of these calls,
which form a ‘graded’ system (Marler 1969) rather than a set of discrete calls. For an
excellent description of the calls of chimpanzees the reader is referred to Goodall (1986:
chapter 6); most or all of the calls described there are also to be heard in Budongo, with
some significant variations (see below).
Pant-hoots
One kind of call given by chimpanzees is a loud and complex call given by individuals
or by several animals joining in one after another to make up an impressive chorus.
Pant-hoots 133