Picture a jaguar crossing a riverbank in the Amazon, unseen by any camera trap, uncounted by any scientist. Multiply that by millions of animals across the planet, and you begin to grasp the strange paradox at the heart of today's biggest conservation statistic. The WWF's newly released 2026 Living Planet Index claims that wildlife populations have shrunk by an average of 73% since 1970. It sounds devastatingly precise.

But how much do we really know about the creatures we have never bothered, or managed, to count? Climate change, it turns out, is the easy problem. Thousands of weather stations circle the globe, and satellites track carbon dioxide from orbit. Biodiversity offers no such convenience.

Wild animals cannot be monitored from space, and counting them on the ground is slow, expensive and uneven. Researchers in Kenya might track lions for decades, while countless amphibian populations in Southeast Asia go entirely unrecorded. The result is a patchwork of data, stitched together from academic studies, fragmentary monitoring schemes, and figures gathered from species that are hunted or fished rather than simply observed. This patchiness matters more than it might seem.