Grave new world: human-induced loss of elders threatens various species

(Source – The Hindu, International Edition – Page No. – 7)

 Importance of Elders in the Animal Kingdom

• Elder animals, from elephant matriarchs to shark grandmothers, guide their families through life’s challenges, imparting crucial knowledge.
• The roles of older animals are crucial across species, particularly in how they stabilize social hierarchies and pass on knowledge for survival.

Aging in the Wild

• Aging varies across species, with older individuals often holding significant roles in social stability and knowledge transmission.
• Researchers highlight that the loss of older individuals due to factors like habitat destruction, hunting, and climate change can significantly impact species, particularly long-lived animals.
• These elders are vital for passing on cultural practices and knowledge of adaptation.
• Elder individuals in long-lived species are essential for knowledge transmission, assisted parental care, and survival strategies in harsh environments.

Examples of Elder Roles in Animal Social Structures

• Elephants: African elephants rely heavily on matriarchs, the oldest females, for survival. Studies show that elephant herds with older matriarchs respond more effectively to threats, such as lion roars. In their absence, younger elephants struggle to adapt and may even face increased risks of conflict with humans.
• Orcas: Older female orcas undergo menopause, enabling them to assist in raising their daughters’ calves. This behavior, known as the grandmother hypothesis, is crucial for the survival of orca populations, as older females help guide the young to feeding grounds and protect them from predators.

Impact of Human Activities on Elders

• Human activities like climate change and habitat destruction threaten the survival of elder animals, leading to cascading effects on the social structure and behavior of species.
• In species like elephants and orcas, the loss of elders disrupts social stability and makes it more challenging for younger members to thrive, increasing stress and vulnerability.

Longevity Conservation Paradigm

• The concept of longevity conservation is introduced, advocating for the protection of older individuals in species conservation efforts.
• This includes preserving age structure, which is critical in long-lived species that rely on older individuals for reproduction, migration, and cultural transmission of knowledge.
• This paradigm is particularly important for species in fluctuating environments, such as fish and reptiles, where older individuals contribute more to reproduction and survival.

Challenges in Implementing Conservation Strategies

• Implementing longevity conservation strategies is challenging, particularly in multi-species fisheries like those in India, where different species grow at different rates and require different management approaches. Fishing gear cannot easily target specific species or ages.
• Despite the benefits, the International Union for Conservation of Nature (IUCN) has not yet recognized the loss of older individuals as a primary criterion for listing species as threatened.

Conclusion

• Protecting elder animals is crucial for biodiversity and ecosystem stability.
• Their knowledge, experience, and roles in social structures help ensure species’ survival, especially in the face of environmental changes and human disturbances.
• Efforts to protect these individuals through strategies like age-based fisheries management can aid in conservation, though significant challenges remain in implementing these strategies.