Grave new world: humans are killing the elders species need to survive Premium

Elders in the animal kingdom hold crucial knowledge, guiding their families and ecosystems through life's uncertainties, and killing them off could affect a species in more ways than the death of other members can.

As people age, they accrue richer experiences and their wisdom deepens.

So do animals. From elephant matriarchs to shark grandmothers, the elders of the animal kingdom carry a treasure trove of knowledge, having guided, and still guiding, their families through the uncertainties of life in the wild.

The earth’s life forms are very diverse and unsparingly complex. No two species age the same. Yet there is also a growing body of evidence that older, wiser individuals are crucial in similar ways to many species.

“Because of the diversity in animal social systems, the important position that older individuals often occupy can be a variety of reasons, but often involves them either being particularly dominant individuals who stabilise the social hierarchy in some way through their presence or by acting as repositories of information that they’ve acquired over their lifetime — which can be particularly important when times get tough,” Josh Firth, an associate professor at the University of Leeds, said.

“There are a range of potential benefits of older individuals across different types of animals. They are not the same for all species,” Keller Kopf, a senior lecturer in ecology at Charles Darwin University, Australia, added.

Without these elders, fish may never find their spawning grounds and birds would get waylaid as they flew across continents.

A review published in Science on November 21 suggested that the worldwide loss of old individuals due to shrinking habitats, hunting, climate change, and other human-caused disturbances can be particularly detrimental to long-lived species.