Although senescence is often observed in the wild, its underlying mechanistic causes can
rarely be studied alongside its consequences, because data on health, molecular and
physiological measures of senescence are rare. Documenting how different age-related
changes in health accelerate ageing at a mechanistic level is key if we are to better
understand the ageing process. Nevertheless, very few studies, particularly on natural
populations of long-lived animals, have investigated age-related variation in biological …