Up close with the Saltwater Crocodiles of the Nilwala River
Sri Lanka is home to around 2,500 to 3,500 saltwater crocodiles, more than half of which are found in national parks. Though not as common here as the mugger crocodile, salties occur in estuaries and riverine systems on the western, southern and eastern coasts of the Indian Ocean island. An increase in the number of crocodile attacks on people has been recorded in recent years, despite some measures introduced to prevent conflict between man and croc.
The largest reptile on Earth, the saltwater croc (Crocodylus porosus), known as geta kimbula in Sinhalese, can grow to lengths surpassing 6 meters (20 feet). This prehistoric creature is the apex predator of riverine ecosystems, found in a vast region around the world, including Sri Lanka, India, to Papua New Guinea and the Indo–Pacific, all the way to Australia.
In Sri Lanka, they’re not as common as the mugger crocodile (Crocodylus palustris), also known as the marsh crocodile. Saltwater crocodiles are found in estuaries and riverine systems mainly on Sri Lanka’s south, west and eastern coasts. Sometimes they can even be found in urban areas such as the nation’s commercial capital, Colombo – moving around the canals and waterways in the city. Some specimens have been seen out at the ocean and even in locations such as suburban Dehiwala-Mount Lavinia, as the crocodiles move between rivers using the ocean as a connector.
In appearance, they are easily identifiable from the mugger crocodile. The head of the mugger is much wider, while the saltwater crocodile’s head tapers toward the snout. The neck of a saltwater croc or “saltie” doesn’t contain any prominent scales compared to the mugger. The mugger is usually greyish in colour, while the saltie has a yellowish hue on the body, especially the belly. The sides of the belly have rough scales similar to the texture of a jackfruit.
It’s in their temperament where the two species differ the most. Muggers are generally timid; only a few attacks on people have been recorded. In contrast, salties are aggressive and there are many cases of deaths recorded due to their attacking behaviour.
Fables about crocodiles swimming in the Nilwala River in southern Sri Lanka’s Matara district are legendary and have influenced both folk tales and folk songs. Of late, the Nilwala and the crocodiles that inhabit the river have been the subject of news, with people being attacked and killed by the riverside.
Such is the saltie’s unparalleled reputation, I took off to the island’s southern coast in search of these magnificent reptiles myself. With the help of local boatmen, I embarked on my first self-styled “crocodile safari” in 2016. The boat ride did not take too long to yield up the first saltie.
It was a small individual, rather shy, and went quickly underwater before we could draw close. We soon realized that there were many crocodiles hiding in the riverbanks and mangroves, mostly in plain sight, but they would quickly go underwater whenever we drew close to them, most of them semi-adults or juveniles.
Going further upriver, we were amazed at the vast variety of birdlife that formed part of this unique ecosystem, ranging from stork-billed kingfishers (Pelargopsis capensis), common kingfishers (Alcedo atthis), striated herons (Butorides striata) and purple herons (Ardea purpurea), to white-bellied fish eagles (Haliaeetus leucogaster), grey-headed fish eagles (Haliaeetus ichthyaetus) and many more.
The further upstream we went, the less populated it became, and there were some areas covered in fast reed beds with no humans in sight. It was in one such area that we came across a large male crocodile swimming across the river. This giant individual measured about 4.5 meters (15 feet) in length. He displayed his dominance over the river by swimming with his head and tail raised high above the water. It was amazing to witness this top predator of the river in its natural habitat, proud and strong. Being in a boat almost at the croc’s eye level gave me an uneasy feeling.
The boat people told me about an even bigger crocodile often seen in the Nilwala, more than 5.5 meters (18 feet) in length. Though we didn’t see him during my first tour, I continued to visit the river over the years and, on one occasion, came across this legendary reptile.
He’d crawled up to a riverbank to bask in the afternoon as crocs do, and could have easily been mistaken for a massive log, given his tremendous size and the colour camouflage. This croc was spellbinding, and I felt privileged to have seen such a giant croc, a rarity these days.
He was as wide as our boat, and as we approached closer, he slid calmly back into the water and disappeared, without trying to overpower us. During my many tours to Matara, I also came across many hatchlings, indicating a healthy population in this ecosystem. One tour up the river gave me a count of 21 individuals.
More croc attacks are being reported, but local people told me that 20 years ago this wasn’t the case. Boatmen have told me that they used to hold swimming competitions in the river without any fear. It’s quite possible that the crocodiles from neighbouring rivers such as the Walawe might have moved to the Nilwala as they gradually lose much of their habitat.
Locals told me there are more crocodiles now, and also that people throw their rubbish, from fish parts and meat, into the water, attracting these giant reptiles and making them lose the fear of humans. This, in turn, imprints in their brain the link between easy food and people, making them swim toward human-habituated areas.
I heard some uncanny tales about how meat shops and even funeral parlours disposed of their waste into this precious water resource, which is now bearing the impacts of pollution and also giving rise to conflicts between man and crocodile.
To prevent crocodile attacks, there are several “croc-proof fences” set up on the riverside, enabling people to bathe in the river. But most that I saw were derelict and in need of repair. Still, I saw people bathing outside the fences, at ease with the river and the lurking dangers.
There are also some barriers across the river upstream using sandbags, an attempt to contain the flow of brackish and saltwater upstream with the tide. The effects of this project need to be assessed along with its environmental impact on the wildlife and fish in this river ecosystem, as well as the livelihood of the fishermen living downstream, and the impact this barrier has when rainfall is at an all-time high and large volumes of water flow downstream.
The Nilwala ecosystem has prevailed and persisted over centuries without disturbance. But its survival and continuity into the future depend on the sustainable strategies adopted by the authorities. The conflict between humans and crocodiles need to be carefully studied and addressed to avoid human deaths while the largest reptile we have known is allowed to survive in the fabled river. The call is for coexistence and not extinction.