Onset of puberty in female bonobos preceeds that of chimpanzees

Puberty is the threshold between childhood and adulthood. Behavior and appearance change considerably during this period – not only in humans but also in our closest relatives, the great apes. In a current study researchers of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have investigated at which age bonobos and chimpanzees, the closest living relatives of humans, enter puberty. In order to determine the onset of puberty the researchers measured the concentration of the hormone testosterone which rapidly increases when male and female primates reach sexual maturity. They found that in males of both species urinary testosterone levels increase at an age of about eight years. Female chimpanzees showed a similar increase at a slightly older age. Female bonobos, however, were found to enter puberty already with five years of age. This is surprising since bonobos are known to be late bloomers whose developmental processes tend to be delayed or take longer in comparison to chimpanzees.