Ageing research on vertebrates shows knowledge gaps and opportunities for species conservation and management

Ageing theories predict that evolution should inevitably lead to an increase of mortality and decrease of fertility with age. However, a recent study across different species shows that this prediction only applies to really few species. In fact there is a great diversity of mortality trajectories in nature. Additionally, empirical studies have previously concluded that age matters: the probabilities of species to die as a function of age are highly diverse. Some species even show that mortality decreases with age (negative senescence). Albeit these findings, most studies still assume that mortality is constant when species reach maturity. The implications of these assumptions have strong consequences not only in the development of evolutionary theories of ageing and population ecology but also in species conservation. By modeling mortality of different species of vertebrates we show that different models are needed to explore the diversity of mortality trajectories in animals. However, our state of demographic knowledge even for vertebrates is by far deficient to incorporate the effects on age. Exploring 13 available datasets on vertebrate life histories traits, our results show surprising figures that highlight the urgency to fill up knowledge gaps to manage populations of threatened species.