Sheep from the edge of the world

A 40-year research project reveals the secrets of aging, climate, and survival in the wild.

In the middle of the harsh North Atlantic lies the small Scottish archipelago of St Kilda, where a population of wild sheep has lived undisturbed for centuries. For more than 40 years, scientists have followed over 15,000 Soay sheep from these remote islands – making the project one of the world’s most famous long-term famous long-term studies of a wild population.

Researchers behind the St Kilda Soay Sheep Project (SSP) have collected lifelong data on every single animal: their birth, diseases, family relationships, genes, and causes of death. This has provided unique insight into how nature itself shapes development, aging and survival – far from the controlled conditions of the laboratory.

What can we learn from sheep?

• Aging in the wild: Scientists from the University of Edinburgh have shown how genes and early-life conditions affect how fast animals age – and that these patterns closely resemble what we see in humans.
• The imprint of climate: Data reveal that milder winters and increased vegetation caused by climate change are associated with growing sheep populations.
• Genetics and evolution: By mapping family relationships across 13 generations, researchers have uncovered how genetic variation, inbreeding, and survival are interconnected.
• Immune system and disease: Long-term sampling reveals how in parasites and immunity change with age in the sheep – and helps explain why some animals survive better than others.

The project has trained and inspired many young scientists from around the world. It is built on values of curiosity, collaboration, responsibility, and openness – with all data made freely available to other researchers.

The sheep of St Kilda help us understand some of life’s biggest questions: how we age, how climate shapes wildlife, and how nature adapts in a changing world.