'Old and wise' animals are essential for the survival of species

Animals, much like humans, accumulate knowledge and wisdom as they age. A growing body of research highlights the profound impact that older animals have on their groups and ecosystems.

However, human activities, especially hunting and fishing, are threatening this invaluable resource, pushing many species toward instability and decline.

Animals that defy time

Some species achieve astonishing lifespans. Bigmouth buffalo fish can live up to 127 years, Greenland sharks can reach 392 years, and certain sponges live for over 10,000 years.

These extended lifespans allow the creatures to gather knowledge about their environments and pass it on to younger generations.

In a recent paper published in the journal Science, researchers noted that Earth’s old animals are in a state of decline.

The analysis, which was based on data from over 9,000 peer-reviewed papers, warns that the few animals reaching old age are often targeted due to their size, unique features, or reproductive potential.

Longevity conservation for old animals

Eliminating the largest and most experienced animals has significant consequences for social structures and group survival. Keller Kopf, lead researcher and ecologist at Charles Darwin University, advocates for “longevity conservation,” which emphasizes protecting older individuals.

“That simplistic idea about old individuals not being important for populations, or for environments, is really not the full story,” said Kopf.

He and his co-authors argue that old animals play vital roles in biodiversity and ecosystem health, and therefore need targeted protection policies and management strategies.

Cultural knowledge in animal populations

Older animals often act as reservoirs of cultural knowledge, maintaining stability within their groups.

Older female elephants, for example, possess a “social memory” that helps identify friends and foes, detect dangers like lions, and guide the group to water sources during droughts. Similarly, postmenopausal orcas excel at locating salmon for their pods.

The removal of older individuals destabilizes populations. This loss of cultural transmission explains why some fish populations fail to recover, even after fishing bans are implemented.

“The trouble is once culture is lost, it is very hard to regain,” said Kopf.

Grandmother hypothesis and group stability

Older mammals often contribute significantly to the survival of their offspring and subsequent generations – a phenomenon known as the “grandmother hypothesis.”

While their reproductive output declines with age, their knowledge and assistance in raising young bolster group success.

For instance, deep-sea corals, which can live for thousands of years, provide critical habitats for marine life. Furthermore, older birds often ensure better care for their offspring.

Fisheries and collapse of collective memory

The targeting of older fish in fisheries has dire consequences for species survival. Culum Brown, a fish biologist at Macquarie University, emphasizes that older fish carry essential cultural knowledge.

“The key thing here is that many important behaviors, such as migration to breeding and feeding grounds, are transmitted socially in lots of species of fish,” said Brown.

“Imagine a fish swimming around in the ocean. The chances of finding the best feeding or breeding locations by chance is virtually zero.” Losing older fish disrupts these learned behaviors, leading to potential population collapse.

Wisdom and social learning in conservation

Kopf’s research underscores the importance of “cultural transmission” in animals. This concept acknowledges that animals possess culture and that older individuals transmit critical social learning.

The accumulated knowledge of older individuals, such as where to locate scarce resources or find shelter, becomes irreplaceable in challenging environments.

More conservationists now recognize the need to preserve social learning and cultural knowledge within animal populations.

“A term that has definitely pretty much only been used for people in the past is ‘wisdom,’ and we’ve used that term – wise – in the title (of the study),” said Kopf. This wisdom, stored in older animals, often holds the key to a species’ survival.

Tragic loss of wisdom and experience

Hunting practices that target older animals exacerbate species’ vulnerabilities.

For instance, older elephants, which play pivotal roles in group dynamics, are systematically hunted for their large tusks and trophy value.

This loss impacts not just the individuals but also the social fabric of their groups.

Kopf’s findings on the importance of older animals offer a poignant reflection on human society. “It’s made me think a lot more about how we don’t value older people in our society,” he noted.

This neglect of older generations results in a loss of wisdom and experience that could benefit humanity. “What is that doing for the modern world?” said Kopf.

The path forward

Longevity conservation could provide a solution. This approach involves targeted policies to protect older individuals, recognizing their role in maintaining biodiversity and ecosystem services.

By prioritizing these efforts, we can safeguard not just individual species but the intricate webs of knowledge and survival strategies they sustain.

Protecting older animals is not just about preserving the past. It is a step toward ensuring the future stability and richness of life on Earth.

As researchers continue to reveal the critical roles of older animals, it becomes clear that their survival is intertwined with our planet’s ecological health.

The study is published in the journal Science.

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