[Animals] Humans are killing off the old and wise animals that hold nature together

[Aronus]

In humans and other animals, ageing is generally associated with a decline in biological function. But scientists are now discovering older animals perform vital roles in po[CENSORED]tions and ecosystems.

Unfortunately, however, old animals can suffer the most from human activity such as over-fishing and trophy hunting. And the value of old, wise animals is not usually considered when we manage animal po[CENSORED]tions and seek to protect biodiversity.

Our new review, published today in Science, draws on evidence from around the world to argue for a new approach called “longevity conservation”.

The loss of old and wise animals has devastating global consequences. Clearly, more must be done to prioritise their survival.

Benefits of a long life:
Cold-blooded (ectothermic) animals such as fish and reptiles tend to keep growing throughout their life. This means older individuals are generally larger than younger individuals.

Being bigger has benefits, especially when it comes to feeding and reproduction. It’s widely known the number of offspring increases with age in fish and many other ectotherms. But it’s only recently been discovered that older mothers of some fish and sea turtles produce exponentially more offspring as time goes on. Their young may also have better chances of survival.

Survival rates are can be higher in offspring from older mothers in other species too. For example, in birds older parents and their helpers often provide more food and better habitat for their chicks, improving fledgling survival rates.

Females from a range of species tend to select older males as mates. These males commonly assume crucial social roles, such as leading long distance movements like migration, and regulating social structures, such as reducing aggressive behaviour. These behaviours influence decision-making with direct consequences for group and offspring survival.

 

 

Humans are killing off the old and wise animals that hold nature together. Here’s what must change