When the water rises: Climate change and the future of Yala's Mugger Crocodiles

In February and March 2025, visitors to Yala National Park stood in disbelief as torrents of brown water surged across once-dry tracks, submerging grasslands and turning familiar terrains into murky lakes.

- BY IFHAM NIZAM

Roads disappeared, jeeps stalled, and for days, one of the most celebrated wildlife reserves in the world remained flooded. But while the tourists could leave, much of Yala's wildlife—especially its ancient predator, the mugger crocodile—had no escape.

Yala, nestled in Sri Lanka's southeastern dry zone, is not just another national park. It is one of the last great sanctuaries for the Crocodylus palustris, or mugger crocodile. "Yala has perhaps the densest wild population of mugger crocodiles anywhere in the world," says Dr. Anslem de Silva, Sri Lanka's foremost herpetologist and a globally respected authority on reptile conservation. “It is a crown jewel in mugger conservation.”

But today, that crown is under threat—not from poaching or pollution, but from the climate itself.

A Reptile Shaped by Water—and Now Endangered by It

The mugger crocodile is one of South Asia's most resilient predators. With a fossil history stretching back millions of years, it has outlived dinosaurs, survived continental shifts, and adapted to changing environments. But the mugger's success has always depended on the predictability of water: seasonal wetlands to hunt, banks to nest, and sunlit lagoons to bask. That balance is now unraveling.

“When people see floods, they assume it benefits crocodiles,” Dr. de Silva explains. “But timing is everything. Floods during the dry season can destroy eggs, displace young, and alter the breeding cycle.”

Crocodiles in Yala typically breed between December and March, with females digging nests in sandy, elevated spots along tank and riverbanks. These clutches—often containing 20 to 30 eggs—require specific humidity and temperature conditions to incubate successfully. When heavy rains strike suddenly and raise water levels, these carefully chosen nesting sites are submerged.