Rendell, L.; Cantor, M.; Gero, S.; Whitehead, H.; Mann, J.: Causes and consequences of female centrality in cetacean societies. Philosophical Transactions of the Royal Society of London, Series B: Biological Sciences 374 (1780), 20180066 (2019)
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.