Crocodile survey - finding new ways to end croc - human conflict

by Dhaneshi Yatawara

Before this new emerging conflict gets into a mammoth scale like the Human - Elephant Conflict, conservationists and wildlife officials are getting together for a new survey on one animal species of great importance. Though much discussed over several years this new emerging Human - Crocodile conflict a sustainable solution could not be found in the past few years to stop life threatening situations for both the human and the crocodile.

The Crocodile Specialist Group (South Asia and Iran), the Dept. of Wildlife Conservation will be conducting the first National Status Survey from March this year, said Anslem de Silva - Regional Chairman for South Asia and Iran, The Crocodile Specialist Group/IUCN/SSC.

Crocodiles are believed to be the largest living reptile in Sri Lanka which plays a key role in the aquatic eco-systems. Sri Lanka has only two species of crocodiles - one is mugger or the marsh crocodile ' Crocodylus palustris ' and the salt water or Estuarine crocodile ' Crocodylus porosus '. Historically Sri Lanka had a large population of mugger crocodiles, but during the heights of the leather industry in 1920-30s, the species was extensively hunted to the point of near extinction. Nevertheless, since legal protection was warranted in 1938, appreciable populations have established, especially within larger tanks in the dry zone. A study conducted by Anslem de Silva and Ruchira Somaweera revealed that limited resource has resulted in an increase of Human Crocodile Conflict. A preliminary survey in 2010 in over 100 water bodies indicates that about 130 persons were attacked resulting in 35 fatalities: 80 percent while bathing and washing clothes in tanks.

Conversely over 50 crocodiles were killed in revenge and as a precaution of preventing future attacks in these tanks. Amidst all this even at present the largest wild mugger populations of the world are known from Sri Lanka. However, they are facing a plethora of threats, making the existing populations vulnerable to future depletion.

Approximately 1,500 to 2,500 individuals are estimated to exist in the wild, most of which are concentrated in several National Parks such as Wilpattu, Yala, Bundala, according to de Silva. Muggers are also found in many 'tanks' or man-made reservoirs in the dry plains of the island. In other areas, C.palustris is threatened by rapid agricultural and industrial developments.

With the exponential increase of human populations in the dry zone due to large-scale agricultural projects, the number of humans and livestock using these water bodies have also largely increased.

The direct encounter with humans have resulted in a conflict that have resulted many muggers being killed to make the water sources 'safe' for bathing, fishing and other daily needs of humans.

An earlier study by Anslem de Silva in 2008 has shown Nilwala river and its tributaries in Southern Sri Lanka had a high incidence of saltwater crocodile attacks, however, all attacks were on people who did not use the traditional crocodile fence - technically known as Crocodile Excluding Enclosures. Crocodile Excluding Enclosures (CEEs) have being traditionally used by people in the southern wet zone where humans frequently use rivers inhabited by saltwater crocodiles.

The CEE is a simple devise where three sides are fenced with wooden poles. Unfortunately people of the South have not been using this over these years.

"This could be a simple but an effective way of saving lives of humans and livestock and reducing the human-induced mortality of muggers in Sri Lanka," said de Silva.

According to the researchers de Silva and Somaweera, segregating the two components; humans and muggers would be the best solution for this emerging concern.

Bringing an action plan Anslem de Silva jointly with Janaki Lenin - an Indian researcher, say that a program of regular, systematic monitoring of known crocodile populations is essential.

Nesting and basking sites should be identified and mapped, and census techniques need to be refined and standardised so that they are scientifically credible. Initially this should be carried out in protected areas as the researchers suggest.

Major threats to crocodiles include accidental drowning in fishing nets, and animals found entangled are often intentionally killed by fishermen. In some areas, Mugger eggs are collected for local consumption. A conservation awareness program that involves local people in the conservation of Muggers is vital to ensure long-term success of any management plan, said de Silva.

With more information coming from public on crocodile sightings close to highly urbanised areas the necessity of a land with ample space to keep such crocodiles in safety became essential. Establishing a crocodile conservation centre will not only support the species, it will also put an end to releasing captured crocodiles into free waterways and parks.

"It is observed that these new crocodiles when released into the wild, rather relocating in a different environment, are killed by crocodiles already living in the habitat," said Anslem. It is scientifically proven that crocodiles have instincts to find its way back to its original place even after taken to another area to avoid human - crocodile conflict. "Because of this there should be a strong enclosure around the areas to ensure safety of the animals," de Silva said.

As de Silva further said placing a value on crocodiles is a proven technique for gaining acceptance of them from local people. Eco-tourism could potentially bring in additional income to local communities, and provided economic incentives for people to be more tolerant of crocodiles.