Behringer, V.; Deimel, C.; Hohmann, G.; Negrey, J.; Schaebs, F. S.; Deschner, T.: Applications for non-invasive thyroid hormone measurements in mammalian ecology, growth, and maintenance. Hormones and Behavior 105, pp. 66 - 85 (2018)
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.