Behringer, V.; Stevens, J. M. G.; Leendertz, F. H.; Hohmann, G.; Deschner, T.: Validation of a method for the assessment of urinary neopterin levels to monitor health status in non-human-primate species. Frontiers in Physiology 8, 51 (2017)
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.