We report the first case of putative empathic response in titi monkeys (Callibebus). Pair bonds between males and females are typically strong, with substantial time spent grooming and tail twining. In an intriguing and unexpected observation we recorded an injured adult out-group male travelling with a neighbouring group. The group appeared to adapt travel patterns to allow him to accompany them, provided pro-social behaviour such as grooming and tolerated his presence at their sleeping site

By genotyping faecal samples from unhabituated gorillas collected over 5 years in Loango National Park, Gabon, we investigated gorilla group composition, social structure and dispersal. We identified 85 individuals, two group dissolutions, one group formation and the movement of 13 gorillas between groups. We also found that females are found in groups containing their female kin more often than expected by chance, suggesting that dispersal may not impede female kin associations in gorillas.