Douglas, P.H.; Hohmann, G.; Murtagh, R.; Thiessen-Bock, R.; Deschner, T.: Mixed messages: Wild female bonobos show high variability in the timing of ovulation in relation to sexual swelling patterns. BMC Evolutionary Biology 16, 140 (2016)
Scientists studying a rare population of tool-using chimpanzees have found that aging can have a profound impact on their abilities—but not all chimps decline equally.