Cambodia: Reborn hope for the Siamese crocodile
HYBRID CROCODILE
Of the 24 known crocodile species in the world, seven are considered critically endangered. This is the situation of the Siamese crocodile. The reptile’s decline began when rice farmers began encroaching on the wetlands where it lives. But commercial hunting to meet the global demand for crocodile skin and meat has pushed it to the brink of extinction.
Many wild-caught Siamese crocodiles were sent to breeding farms. In 2010, at the height of their activity, there were about 900 in Cambodia, and they were home to more than 250,000 reptiles. The sector has collapsed in recent years as demand for crocodile skin products has declined due to changing fashion trends and rising costs of breeding.
Faced with this situation, breeders try to sell their farms. This is the case of Aim Kim San, who is at the head of a small infrastructure located near the Tonle Sap lake in the suburbs of Siem Reap. “It was a very lucrative business,” said the 65-year-old, standing on a podium overlooking the hard concrete enclosure where some of the farm’s 135 breeding crocodiles are crammed. “All I want now is to stop selling motorcycle spare parts.”
Contrary to what you might think, it’s not a good idea to release reptiles that farms want to save into the wild. Farmed Siamese crocodiles have largely lost their genetic diversity due to hybridization with saltwater crocodiles and Cuban crocodiles, a species introduced to Cambodia several decades ago. And this turned these large shy animals into particularly aggressive animals, making them unsuitable for wild life.
Most of the Siamese crocodiles released in Cardamoms by Fauna and Flora International over the past 10 years come from a small breeding program that the organization manages near Phnom Penh, the Cambodian capital. The complex process has so far resulted in the reintroduction of 130 reptiles to Cardamoms, some of which only come from farms.
Although this allowed the population of the reptile to increase in the region (about 300 individuals), conservation organizations want to strengthen measures to ensure the genetic diversity and survival of the species.
They can rely on a proven method to help them: DNA testing to identify the most genetically pure Siamese alligators. Instead of sending samples abroad, Cambodian researchers now perform these tests in the country. “Our work has been greatly facilitated,” says National Geographic researcher Pablo Sinovas.
YEAST AND THE ENVIRONMENT DNA
Patrol activities are also easier in the Cardamoms, thanks to increased law enforcement activity in the region, which helps prevent illegal logging. In addition, poachers are less likely to target crocodiles. Not all threats to the reptiles have disappeared, but the main threat is local fishermen who injure or even kill crocodiles while fishing.
Local residents often applaud efforts to protect the Siamese crocodile, not least because conservation spending in the area has allowed new infrastructure to be built, including a Buddhist temple and school. Villagers who report that they have crocodile nests and eggs also receive financial rewards. “I’m happy to report the crocodile I saw in my fields, it happened twice before,” says 78-year-old farmer Srey Ny, who recalls that there were once plenty of Siamese crocodiles and tigers in the area.
The reptiles released at Cardamoms this year were fitted with satellite tags for the first time. According to reports, most people did not move away from the launch site.
Researchers have also begun using environmental DNA (or eDNA) to identify Siamese crocodiles in the wild. Despite the complexity of this technology, scientists were able to detect reptile eDNA in 19 out of 21 environments.Pablo Sinovas.
BALANCE OF ECOSYSTEMS
The reintroduction of 15 Siamese crocodiles to the Siem Pang Wildlife Sanctuary in northern Cambodia earlier this year is the country’s first outside of Cardamom.
Organized by conservation group Rising Phoenix, the release was difficult, with locals more wary of the reptile’s return than the Cardamoms. With alligators disappearing from the region for several decades, many residents near the release site were concerned about the idea of the nearby waterways being populated by the large predators.
After several months of work, environmentalists managed to calm the local population. Alligators in the breeding farm and undergoing genetic testing can thus be released into the pond. At first, the latter remained in a large wooden cover, which would split under the rain and thus allow animals to enter the canals of the swamps.
The pilot project plans to release an additional 20 crocodiles still in the Siem Pang reserve next year. “Ultimately, we want to see a self-sustaining crocodile population as an integral part of a healthy aquatic ecosystem,” says Rising Phoenix President Jonathan Eames.
Although the species has always been present in Cambodia, the impact of reintroductions on fish and other animal populations is unclear. “I would be surprised if the return of such an apex predator didn’t cause significant changes in the ecosystem,” says Jack Eschenroeder, a fisheries biologist with the California-based conservation group FISHBIO who studies habitats. In Siem Pang, crocodile numbers and performed several eDNA studies.
For Pablo Sinovas, the campaign to save the Siamese crocodile from extinction is part of a larger effort.
“Its survival is not just an ecological necessity; This is a symbolic imperative if we hope to preserve nature on Earth.”
