Lanka's first crocodile survey this month
By Dhaneshi Yatawara
June will be the month for crocodiles in the Sri Lankan wildlife
field. News gets reported periodically on human deaths and injuries
throughout the year. Surveys have been done by researchers in isolation
on this Human - Crocodile conflict on different areas of the country.
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Anslem de Silva |
We hear many incidents related to the Human - Elephant conflict.
Wildlife authorities and experts have brought in numerous solutions over
the past years to the Human - Elephant conflict but the Human -
Crocodile conflict has not been addressed properly. Currently many
crocodiles are killed and their natural habitats are depleting.
"We do not know the status of our crocodilians," said Anslem de Silva
expert herpetologist of Sri Lanka and Regional Chairman of the Crocodile
Specialist Group for South Asia and Iran.
Rather than shedding 'crocodile tears' on the status of these animals
the Department of Wildlife Conservation and the Crocodile Specialist
Group of the International Union for Conservation of Nature (IUCN) will
be starting an islandwide survey on crocodiles this month.
The Crocodile Specialist Group - which is a worldwide network of
biologists, wildlife managers, government officials, independent
researchers, NGO representatives, farmers, traders, tanners, fashion
leaders and other private companies - is a working unit to ensure
preservation of crocodiles. A leading fashion house chain, has come out
to help this first National Crocodile Survey.
Being the largest living reptile in Sri Lanka, crocodiles play 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. The
biggest number of mugger crocodiles is believed to be found in the Yala
or the Ruhuna National Park, according to Anslem de Silva. A recent
survey conducted by de Silva with the assistance of the Department of
Wildlife Conservation, revealed that over 500 muggers are in Yala.
Two types
Also known to thrive in man-made reservoirs and irrigation canals and
being a large carnivorous reptile, the mugger crocodile eats fish, other
reptiles and small mammals such as monkeys. Muggers prefer slow-moving,
shallower bodies of water rather than fast-flowing, deep areas. In fact,
most vertebrates that approach to drink water are a potential prey of
the mugger and may suffer being seized and dragged into the water to be
drowned and devoured at leisure. Large adults will sometimes prey on
large mammals such as deer and the average 450 kilogram domestic water
buffalo. At night they sometimes hunt on land, lying in ambush near
forest trails.
This species is generally considered to be occasionally dangerous to
humans. A preliminary survey done by De Silva in 2010 in over 100 water
bodies indicated that about 130 odd persons were attacked with 35
fatalities. And roughly 80 percent fatalities were while bathing and
washing clothes in tanks.
"Sharing an essential but a limited resource like fresh water has
given rise to the increase in Human - Crocodile Conflict," de Silva
said. Investigations have revealed that most of the attacks were due to
mistakes by the humans themselves.
"The Crocodile is a very intelligent animal; it observes its prey for
days, even months before attacking," said de Silva explaining the
animal's behaviour.
Enclosures
"The crocodile does not attack spontaneously. It watches the
movements on the river banks and even though people have seen crocodiles
swimming in the vicinity at a distance they should be aware of the
danger. People should either change the place they use on the river or
the tank or else should build Crocodile Excluding Enclosures," he said.
Crocodile Excluding Enclosures (CEEs) are traditionally used by
people living in the southern wet zone of the country where the salt
water or estuarine crocodiles inhabit, the herpetologist explained. Yet
this does not exist in the dry zone.
"This could be a simple but effective way of saving lives of humans
and livestock and reducing the human-induced mortality of muggers in Sri
Lanka," he added. An earlier study by de Silva in 2008 reveals that at
Nilwala river and its tributaries in Southern Sri Lanka a high incidence
of saltwater crocodile attacks prevailed: however, all attacks were on
people who did not use the traditional CEEs. Dividing the areas used by
muggers and humans would be the best solution to save both.
"The direct encounter with humans have resulted in a conflict that
has caused many muggers being killed to make the water sources 'safe'
for bathing, fishing and other daily needs of humans," de Silva said.
"Historically Sri Lanka had a large number of mugger crocodiles, but
during the height of the leather industry in 1920-30s, the species was
extensively hunted to the point of near extinction," said Anslem de
Silva explaining the current plight of these rough beauties. In the 20th
century, until the Fauna and Flora Protection Act of 1964 was enforced,
crocodiles were extensively hunted for their skins and the hunting ended
with introduction of the large scale persecution in the Act.
Protection
Nevertheless, since legal protection was given in 1938, an
appreciable number has been established, especially within larger tanks
(reservoirs) in the dry zone. Mainly a freshwater species, the mugger
crocodile is in lakes, rivers and marshes.
The current project will survey the status of crocodiles in National
Parks as well as those inhabit outside Protected Areas. One officer from
the Department of Wildlife from the respective park and one member of
the local Crocodile Specialist group will be the members of the research
team for each area. Headed by Anslem de Silva as the chief researcher,
the Crocodile Specialist Group comprises Adrian R. Gabriel, Dinal
Samarasinghe, Anushka Kumarashinghe, Suranjan Karunarathna, R.M. Ahamed,
Velauthen Vijaya Anand, Malshani Samaraweera and M.B. Madawala. The
Wildlife conservation officer will first do the counts in the randomly
selected tanks for one week or a month (depending on the conditions) and
the data will be recorded. These tanks will be re-surveyed along with
one Crocodile Specialist Group member who will conduct day counts and
Night 'eye-shine' counts along with the Wildlife officer which is the
most accepted survey technique.
The count and the data gathered in the survey will be useful for Red
List assessments and developing a sound conservation management plan
through understanding threats on these animals, according to de Silva.
The Department of Wildlife Conservation will get to know the population
structure of one group of animals in a particular year in their parks.
Solutions
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 has become an essential factor as well.
Establishing a crocodile conservation centre would be a support for
the species as well as it will also put an end to releasing captured
crocodiles into free waterways and parks.
As de Silva further said placing a value on crocodiles is a proven
technique for gaining acceptance to them from local people. Eco-tourism
could potentially bring in additional income to local communities, and
provide economic incentives for people to be more tolerant of
crocodiles.
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