I guess there isn't specific published data on this topic in the literature, in which case your best bet would be to contact some of the research groups working on long-observed groups that have reliable pedigree data (e.g. Max Planck Institute Dept. of Primatology or NGOs like the Jane Goodall Foundation).  Warning: such groups tend to be very protective of unpublished data, so maybe suggest collaboration and be very clear about what you want to use the data for. Sorry can't be of more help.