I think with Shona, she’s unfortunately quite isolated due to her inability to breed and therefore suffers from a lack of support. Prior to the arrival of the new females, she was the lowest ranking female and will no doubt be supplanted by them too as they eventually have offspring of their own. Shona receives almost no support from Shiba, who is the younger sister of Shona’s mother. Shiba has her own family of four offspring and has no need for support from Shona either. Shona should essentially be regarded as a separate family group on her own, rather than an extension of Shiba’s. While Sembe is indeed playing second fiddle to her younger brother Sudi for his mother’s attention, she still receives support from Shiba and of course her two adult brothers.
Lani as you mention is quite aloof from the other families. Despite both being young adolescent females, her and Sembe have little to do with each other. I believe Lani’s aloofness is due to the high ranking position of her family and her having never needed to make an effort with the other chimpanzees. Sembe, on the other hand, is most likely behaving like her mother. Shiba is not a social chimpanzee, preferring the company of her own family and interacting little with the other chimpanzee. Her protectiveness of Sembe during her early years may have restricted opportunities for Sembe to socialise to the extent of other chimpanzees such as Shikamoo or Sule.
Koko was hand raised for at least the first eight years which is most likely the cause for some of her social issues. She has caused issues for several females in the group, including Shiba and Kuma. In 2004, she and Kamili savagely attacked Shiba’s juvenile son, Samaki, who would have likely been killed if not for Shiba’s ferocious intervention. While infanticide in chimpanzees is common, an attack on a juvenile like this would be considered unusual and unprovoked. Certainly not normal behaviour. Shiba and Kuma have both since risen to high ranking positions and Koko is of little bother to them now, but I’d imagine she’s been quite the challenge for the new females.
Lubutu was indeed vasectomised after the birth of Sembe and Sule in 2008 (his fifth and sixth surviving offspring), but unlike castration, vasectomisation has no obvious effects on a male chimpanzee or his ability to mate with females so it’s unlikely the other females would know he’s incapable of siring offspring. They are wise to support him as he is the alpha, but to mate with the other males on the side to hedge their bets in case one of them supplants him. Samaki is Lubutu’s right hand man and is second in command. In return for his support, Lubutu allows Samaki to mate with some of his females, which led to Samaki fathering one of the recent infants in 2014.
