Critically endangered species makes an unlikely comeback

 A nearly extinct crocodile species returned from the brink in Cambodia

A generation ago, the Siamese crocodile was thought to be extinct. A 13-year conservation effort has helped the critically endangered species make a comeback. In Cambodia, the crocodile is akin to China's giant pandas or India's tigers, and the animals are being bred in captivity before being released in the wild, as reported. First reintroduced to their natural habitat in 2012, the crocodiles produced 106 eggs in June. The Siamese crocodile was taking its time, lagging others that had already wriggled out, chirping, into the sand. Adults can be up to 4 meters (13 feet) long and weigh up to 350 kilogram (770 pounds). They have few natural predators. But these hatchlings are vulnerable and their chorus of shrill calls was a signal for mothers to protect them and for stragglers to catch up. Hor Vichet, a zookeeper at the nonprofit Fauna and Flora’s breeding centre for the critically endangered reptiles in Cambodia’s Phnom Tamao, broke the rest of the shell. “It’s time to go into the world,” he said. It marked a high and the most promising sign in two decades that the Siamese crocodile is thriving.

Siamese crocodiles are making an unlikely comeback. Once widespread across Southeast Asia, demand for leather made from their skins decimated wild populations in the last century. Thousands were hunted or captured for breeding at farms. By the late nineties, they were thought to be extinct. A critically endangered crocodile species, once thought extinct in its Cambodian habitat, is clawing its way back thanks to painstaking conservation work. The hatching of clutches of critically endangered Siamese crocodiles is an unlikely comeback, aided by an even unlikelier ally. Crocodile farmers who had nearly hunted the species to extinction in the first place now play a vital role in providing purebred reptiles for captive breeding. There are about 1,000 of the crocs in the wild, including 400 in Cambodia. They were nearly killed off by habitat destruction, poaching, and crossbreeding. The hunters who captured, bred, and massacred the creatures to sell their skins have helped them bounce back, too.

But a 2000 survey in the Cardamom Mountains in western Cambodia found a vestige of a wild population. These misty rainforests were among the last strongholds of Khmer Rouge guerrillas who fought the government until 1999. That, combined with the reverence of local Indigenous communities saved this lingering enclave of crocodiles. But they were still too few and too scattered to recover the population. Conservationists realized that saving the species would require captive breeding of purebred, fertile crocodiles. The crocodile farmers who had nearly hunted the species to extinction now play a vital role in that effort. They are the source of purebred, fertile crocodiles, pulled from a population of 1.5 million mostly hybrids that were bred for leather. After the females lay eggs, the eggs are incubated at the Phnom Tamao Wildlife Rescue Centre, allowing the crocodiles to develop before they are brought to a national park in the Cardamom Mountains.

Today there are about 1,000 Siamese crocodiles in the wild, roughly 400 in Cambodia and the rest scattered in Vietnam, Laos, Thailand and Indonesia. Protecting the reptile also requires safeguarding its habitat in the Cardamom Mountains, a diverse ecosystem that is one of the last surviving rainforests in Southeast Asia. It stretches over an area larger than Denmark, helping to trap earth-warming greenhouse gases from the atmosphere. Only one in 20 crocodiles born in the wild survives, but if they are bred in captivity and not released until they reach 1 meter in length, "their chances of survival increase exponentially." The efforts are finally paying off: The first crocodiles were reintroduced into the wild in 2012 and they have begun breeding in the wild: over a hundred eggs were discovered in the forests in July, the most so far. “We are still far from being able to say the species is in a good place,” admitted Pablo Sinovas of Fauna and Flora. “But it is making progress.” The conservationists also have to protect the reptiles' habitat since 32% of the country's tree cover was lost from 2001 to 2023, according to Global Forest Watch. "Protecting habitat is the most important part of this whole project," Pablo Sinovas of Fauna & Flora said. That's why the discovery of the eggs was such good news. They produced 60 hatchlings.

The conservationists faced big challenges when they began their project in 2011. There were over 1.5 million crocodiles languishing in farms across Cambodia, Thailand and Vietnam, but few were purebreds. Farmers had bred Siamese crocodiles with larger, more aggressive species to get skins with textures demanded by fashion brands. Releasing those hybrids into the wild might hasten the disappearance of the purebred species. It also could pose a threat to people. Evidence of Cambodian reverence for Siamese crocodiles lives on in toothy carvings on the walls of the Bayon temple in the country’s Angkor Wat temple complex, but the hybrids are not the same animals. “That would be a problem since some of these species are aggressive to humans. And you don’t want them in the wild,” he said.

Crocodiles are social species and once together, they “find their own hierarchy,” said Iri Gill, who manages cold-blooded animals at the Chester Zoo in the UK, which supports the breeding program. After the breeding season, females lay eggs which are then kept in an artificial incubator where humidity and temperatures are monitored carefully to replicate the conditions of a nest in the wild. “That is the key stage to hatch those juveniles out and raise them to a strong age before their release,” said Gill. In the wild, fewer than 1 in 20 crocodile hatchlings make it to adulthood. Their chances of survival increase exponentially if they’re released after they grow to a meter (3.4 feet) long. “That’s why these captive breeding programs have been working across the world,” he said.

Today, demand for crocodile leather has diminished and many of the farms had been losing money since the pandemic, said crocodile farmer Ry Lean. So the experts scoured through crocodile farms across Cambodia, working with farmers and scientists to find purebreds. The few that were eventually identified were brought to the wildlife centre at Phnom Tamao to breed in captivity. Their eggs were were incubated artificially and the first group of 18 purebred young crocodiles was released in the Cardamom Mountains, laying the foundation for resurrecting the species. Conservationists still scout the farms searching for purebred Siamese crocodiles. They are also working to protect the habitats where the purebred juveniles are released. In 2001-23, Cambodia lost nearly a third of its tree cover, according to Global Forest Watch, a platform run by the non-profit World Resources Institute.