Consortships
A relatively unusual kind of party consists of a male–female consortship. This was first
described for the Gombe (Kasakela) community and appeared to be an alternative mat-
ing strategy adopted by some males who ‘sequestered’ females and took them on safari
away from the other members of the community for a greater or lesser time while the
female was in oestrus. This appeared to be a mating strategy by certain males to avoid
competition with other males (Tutin 1979; Goodall 1986).
At Sonso, consortships appear to be scarce and such data as we have comprise a few
observations of pairs consisting mostly of single adolescent or young adult females in
oestrus being found moving together with single adult males, seen together over a period
of several days. Whether these pairs are preliminary courtships which might lead to
subsequent mating when the female is fully mature is not clear and requires further
study. For example, Kewaya, a subadult female, and Kikunku, an adult male, were seen
together on several consecutive days, with Kikunku sapling shaking to Kewaya, a
display which in the context of courtship seems to mean ‘Come here!’ or ‘Follow me!’.
A different kind of consortship, more like the one described for Gombe, may however
occur at Sonso. For two weeks, from 9 to 24 April 2002, the alpha male Duane disappeared
and this coincided with the disappearance of the adult female Nambi. They reappeared
together on 24 April. Sean O’Hara who was working on sexual strategies at the time wrote:
We suspect, although cannot confirm, that the two were on a consortship. Duane had been seen the
day before their disappearance trying to lead Nambi away from the group by sapling shaking.
Nambi was reluctant and had no sexual swelling. At the time she returned (two weeks later) she
again had no sexual swelling and it is suspected that she stayed away through the whole period of
her tumescence, which Duane monopolized (if indeed they were on a consortship).
This is probably the first well-recorded possible consortship at Sonso, although
Duane and Nambi, who had a swelling, were also absent together on one earlier occa-
sion. On a third occasion Black was seen leading Kutu who had a swelling. And recently
a very interesting case has been seen: in July 2003 we observed Black and Polly in a
very tight relationship with each other. Polly was not in oestrus(completely lacking
a swelling) but Black was copulating with her,^38 demanding that she accompany him by
branch-slapping in the tree, and when he came down to the ground by knocking a large
dangling liana against the tree trunk making a loud noise. At this Polly descended and
Black followed her very closely as they disappeared rapidly on the forest floor. This
incident is in contrast with the consortship situation more commonly encountered,
e.g. at Gombe, where consortships are a mating strategy of low-ranking males; Black
was at this time the second or third ranking male at Sonso.^39
Consortships 99(^38) This is very unusual and was the first time I (or others present) had seen a copulation where the female
was not in oestrus. Black, an aggressive male, was behaving aggressively to Polly, who was a newcomer to
Sonso. However, the copulations were not forced, in that Polly did not give fear screams or attempt to run
away from Black. 39
Thanks to Sean O’Hara for pointing out this difference.