When drought grips the African savanna, elder animals take the lead. An aging elephant matriarch leads her herd to water she remembers from decades past. In the cold Pacific, an older killer whale guides her pod to elusive salmon, sharing her catch when prey runs thin. And over the open ocean, a seasoned albatross traces vast, invisible routes it has refined over years, returning unerringly to feed its chick.

Across land, sea, and sky, these elder animals deploy memory, skill, and experience accumulated over long lives. So what happens when such older individuals are selectively removed through hunting, fishing, or other human pressures? Researchers say the loss may not be immediately visible, but it is profound: The knowledge that underpins population survival begins to disappear.

For decades, conservation has focused on numbers: how many animals remain in a population. But a growing body of research suggests this lens is too narrow, and that the loss of elder animals can reshape populations in ways that simple counts fail to capture. “Not all individuals contribute equally,” says Keller Kopf, a senior lecturer at Charles Darwin University in Australia. “Older animals play roles that are often invisible in simple population counts.”

“There has been mounting evidence for the knowledge, skills, and leadership roles that older individuals have within their societies.”

In 2024, a paper in Science led by Kopf introduced the term “longevity conservation,” giving name to a simple idea: protecting wildlife means maintaining the full age structure of populations, including their oldest members. The concept quickly moved beyond theory. Last year, the International Union for Conservation of Nature adopted a resolution on the issue, formally recognizing the importance of protecting older individuals and elevating the concept into conservation policy. And at the recent United Nations Convention on Migratory Species meeting in Brazil, protecting “old and wise” elder animals was a major talking point.

Scientists say elder animals often play several critical roles in how populations function, broadly falling into three categories: ecological knowledge, reproduction, and immunity. They carry knowledge that guides survival, play outsized roles in producing the next generation, and possess stronger defenses against disease built up over time. Together, these qualities can make the difference between populations that endure and those that slowly fall apart.

Read the full article about the role of elder animals in species' survival by Stefan Lovgren at Yale Environment 360.