Andhika Chandra Ariyanto crouched over camera trap footage in Java's fractured forests, watching one of Earth's rarest big cats move through a landscape that should have swallowed it whole. The Javan leopard—fewer than 350 mature individuals surviving on an island where more than 150 million people live—persists not in the pristine reserves that dominate conservation strategy, but in recovering forests, plantation edges, and the tangled margins of expanding towns. His doctoral research reveals a survival story that rewrites how the world should think about protecting large predators in human-dominated lands.
For decades, conservation efforts have fixated on primary forest—the old-growth woodland never logged or cleared—as the fortress where endangered species make their stand. Ariyanto's work, conducted at the University of Twente's ITC using camera traps and spatial modeling across Java's national parks, tells a different story. The leopards regularly roam secondary and regenerating forests, the woodland that regrows after disturbance, and they move through production landscapes adjacent to protected areas. These "second-rate" forests, long dismissed by conservation planners, are doing much of the actual work of keeping the species alive. They serve as habitat islands and as corridors—critical connective tissue in a landscape increasingly fragmented by roads, railways, and sprawling cities.
The research also reveals the leopard's flexibility with prey. Rather than depending on any single species, the cats thrive in areas with diverse prey communities. That diversity, Ariyanto found through his camera trap surveys, matters enormously where forests are broken into patches. A forest with varied hunting opportunities is far more resilient to disturbance than one dependent on a single food source.
What makes this work urgent is the acceleration of fragmentation on Java. Roads and railways are slicing the island's remaining forests into ever-smaller islands, isolating populations and raising the specter of local extinction. But Ariyanto's spatial models offer something planners can act on: maps showing where ecological corridors are most broken, which bottlenecks block leopard movement, and—most critically—where reforestation would reopen the most routes for the species to move between otherwise isolated patches. His work flags which areas to restore first, where links between protected areas most need strengthening, and where new development would cause the most damage.
This shift from reserve-focused thinking to landscape-scale conservation reflects a broader global reality. Large predators increasingly live outside park boundaries, moving through lands where people farm, log, and build. "A national park is no longer enough on its own," says Tiejun Wang, Ariyanto's supervisor at Sun Yat-sen University. "The future of the leopard will be decided in the places where people already live and work."
As Ariyanto defended his thesis—titled "Spatially explicit conservation of the Javan leopard in human-dominated landscapes"—in June, his work stood as one of the most comprehensive spatial assessments of the species yet completed. For Java's leopards, and for large carnivores worldwide trying to persist in landscapes remade by human hands, it offers a concrete blueprint: the future depends not on fortress reserves alone, but on stitching fragmented lands back together, one recovering forest and strategic corridor at a time.