- A new study confirms that Myanmar’s last population of saltwater crocodiles is perilously isolated and that without efforts to connect suitable coastal wetlands, the future of the species is in the country is uncertain.
- Deforestation and conversion of coastal habitats for commercial production, persecution due to conflicts with people, and hunting and wild capture to supply demand for crocodile meat and skin products have all taken their toll on crocodile numbers.
- The researchers recommend conservationists and policymakers in Myanmar focus on reconnecting remaining coastal habitats, including existing coastal protected areas, and identify key crocodile habitat areas and potential movement corridors to aid such conservation action.
- Enhancing coastal habitat connectivity would not only enable crocodile population recovery, it would also reduce pressure on communities coping with negative interactions with crocodiles.
With their tooth-packed jaws, dinosaur-slit eyes, and stealthy ability to emerge without warning through the surface of muddy-brown waters, saltwater crocodiles are indisputably one of the world’s most revered top predators. But despite their predatory prowess, the species is in decline in many parts of its range.
In Myanmar, little was known about how many saltwater crocodiles (Crocodylus porosus) remained, but scientists believed the species that once ranged across the country’s coastline had been devastated by a series of factors. Deforestation and conversion of coastal wetlands for agriculture and plantations, persecution following conflicts with people, and hunting and wild capture to supply demand for crocodile meat and skin products have all taken their toll.
Now, a new study in Biological Conservation confirms that their numbers are indeed low. The findings, based on a combination of historical species distribution data, state-led croc counts, and new information from recent spotlighting and camera-trap surveys, indicate that the species is now confined to a single protected area in the Irrawaddy Delta called Meinmahla Kyun Wildlife Sanctuary, numbering between 50 and 85 individuals.
“[This] small population [is] very vulnerable to any extreme events, [such as] tsunamis and storms … and to things like inbreeding depression,” study co-author Alice Hughes, an associate professor at the University of Hong Kong, told Mongabay. “So unless action is taken to widen their distribution, then the population cannot grow any more, it’s already likely near the carrying capacity.”
In their study, Hughes and her colleagues identify key crocodile habitat areas and potential movement corridors where they recommend conservationists and policymakers in Myanmar focus action to reconnect remaining coastal habitats, including existing protected areas.
As apex predators at the top of the food chain, saltwater crocodiles play a crucial role in maintaining nature’s balance. By keeping prey populations in check, they set off a cascade of interactions that in turn shape the structure and function of the coastal and estuarine ecosystems they inhabit. “If we conserve crocodiles, all of the mangrove-dwelling bird species, and the myriad of fish species, for example, that depend on these environments will also be conserved,” Hughes said.
Pablo Sinovas, Cambodia country director for Fauna & Flora International (FFI), echoed Hughes’ assertion that crocodiles make superb conservation focus species. “By virtue of their relatively large and undisturbed habitat requirements, crocodiles can be excellent umbrella species; that is, their conservation benefits many other co-occurring wildlife,” Sinovas, who wasn’t involved in the Myanmar study, told Mongabay in an email.
“Coastal wetlands are increasingly threatened and fragmented, and [are] incredibly valuable not only for wildlife but also for people, offering a host of services ranging from food security and coastal protection to carbon storage,” Sinovas added. “Leveraging conservation of these incredible reptiles to protect the ecosystems they’re part of is thus a win-win situation if you think long-term.”
Saltwater crocodiles are listed as a species of least concern on the IUCN Red List, having a wide geographic range that encompasses coastal areas from the west coast of Australia to the east coast of India. Nevertheless, the species’ range in Southeast Asia has contracted severely in tandem with the decimation of mangrove cover over the past few decades. Researchers say the species could be extinct, for instance, in Cambodia, Thailand and Vietnam, making the albeit small and isolated population in Myanmar all the more important as a reservoir of genetic diversity.
Reconnect core coastal habitats
Kay Zin Than, the new study’s lead author and a researcher at the Chinese Academy of Sciences, said the fieldwork to investigate crocodile distribution was particularly rewarding — even though at one point her survey boat sank while navigating a stretch of water with crocodiles present. The survey team was rewarded for its intrepid commitment, however, with views of endangered Irrawaddy dolphins (Orcaella brevirostris), signaling the importance of Myanmar’s remaining coastal wetlands for other threatened species that have, like the crocodiles, lost much of their natural habitat.
Equipped with the new baseline information of crocodile numbers, distribution and habitat availability, the next step will be on-the-ground action to reconnect core croc habitats, Kay Zin Than said. “We now know which areas we need to conserve, so next we [need to] collaborate … to try and focus on the conservation of saltwater crocodiles and address biodiversity loss.”
The researchers recommend establishing an ecological network of coastal habitats to afford the crocodiles space to disperse across a wider area. To this end, the study identifies a suite of core crocodile habitat areas and movement corridors where conservationists and policymakers can target their efforts. These areas include habitat patches in Myanmar’s Rakhine, Ayeyarwady, Yangon, Mon and Tanintharyi regions.
Delineating specific geographic areas in which to target conservation action is particularly crucial in coastal areas, which are typically overlooked in conservation planning, Hughes said. “The interface between the land and the sea, those brackish areas, often fall in between ministerial jurisdictions,” she said. “You might have one [government department] in charge of land management, and another dealing with the sea, so the coastal areas can fall between the gaps.”
The key will be establishing good partnerships between government agencies, such as the Myanmar Forest Department, international conservation NGOs still operating in the country, such as FFI and WWF, and local NGOs and academics, the authors say.
However, a major challenge will be ensuring tangible benefits for the crocodile population without imposing intolerable risks for people. Human-crocodile conflict is a stark reality for many communities living near wetlands frequented by crocodiles.
“These are shared landscapes,” Hughes said. “There’s a lot of people farming in coastal areas [and] a lot who are dependent on fishing, and so human-crocodile conflict is a very real issue. Managing these areas has to take into account the needs of people in them as well. That means thinking about livelihoods, thinking about [people’s] security and safety and thinking about encroachment. Any program like this, especially with a large carnivore, that doesn’t have sufficient stakeholder engagement, education and inclusion is going to fail and is going to drive resentment.”
Hughes said this is why local knowledge and expertise is crucial, particularly in Myanmar, where the political conflict has made collaborative research fraught with difficulty. Sensitivity to local contexts is crucial, she said, to ensure conservation work is accessible to communities and that it can successfully drive government policy to enable better protections for both wildlife and people.
“If we see a continuation of the loss of habitat and a lack of connectivity among them, it’s not just going to be the crocodiles that suffer; all the other species that share these habitats — many of which we have even less data on — will suffer too,” Hughes said. “It’s crucial that we do protect these key areas.”
Carolyn Cowan is a staff writer for Mongabay. Follow her on 𝕏, @CarolynCowan11.
Banner image: A saltwater crocodile rests on a riverbank in Southeast Asia. Image by Carolyn Cowan for Mongabay.
Citations:
Than, K. Z., Zaw, Z., Quan, R., & Hughes, A. C. (2024). Biodiversity conservation in Myanmar’s coastal wetlands: Focusing on saltwater crocodile habitats and connectivity. Biological Conservation, 289, 110396. doi:10.1016/j.biocon.2023.110396
Than, K. Z., Strine, C. T., Sritongchuay, T., Zaw, Z., & Hughes, A. C. (2020). Estimating population status and site occupancy of saltwater crocodiles Crocodylus porosus in the Ayeyarwady Delta, Myanmar: Inferences from spatial modeling techniques. Global Ecology and Conservation, 24, e01206. doi:10.1016/j.gecco.2020.e01206
See related story:
Could mugger crocodiles be brought back from regional extinction in Bangladesh?
FEEDBACK: Use this form to send a message to the author of this post. If you want to post a public comment, you can do that at the bottom of the page.
Credits
