Why South Africa’s leopards shrank to half their normal size

Animals of the same species don’t always look the same. From birds with different beak shapes to mammals that vary in size or color, populations living in different places can often look very different. What’s much harder to pin down is why these differences arise. Are they shaped by local environments? Or driven by natural or sexual selection? Or are they simply the result of the random loss of gene variants as populations become isolated and slowly diverge over time? I’m part of a team of leopard conservationists and researchers who set out to answer some of these questions when we investigated a remarkable population of fewer than 1,000 leopards in South Africa’s Cape Floristic Region, an area that covers the country’s Western Cape, and parts of the Eastern Cape and Northern Cape.