Human elephant conflict: Bunds and trenches could form a viable solution (Sri Lanka)


By Wimalanga Samarasinghe, The Sunday Times

Date Published
Much has been discussed about the sad plight of people inhabiting villages bordering national parks (wild life sanctuaries) and wild elephants which stray into human habitations from these sanctuaries. Although electrified fences have been installed to prevent elephants from straying into human habitations, this method has become less effective as elephants have found ways of breaking these fences and entering villages to feed on crops, sometimes even destroying houses.
Instances where villagers have been killed by wild elephants are reported more and more frequently now. As a result, the villagers have resorted to shooting or laying various forms of traps, including the most inhuman practice of laying explosives laden bait which explodes in elephants’ mouths causing agonising deaths.
The present Government, recognising the severity and urgency of this problem has earmarked Rs. 4000 million for three years in its budget for 2016, to resolve the human elephant conflict and to conserve the rich bio-diversity in Sri Lanka. Nevertheless a viable plan of action to resolve this problem is yet to be conceived, except installation of electrified fences.
To find a durable solution to this human-elephant conflict, we have to identify the issues which have led to this situation and take measures to overcome them. In my opinion, the main issues which have led to this situation are:
1. Gradual encroachment of humans into sanctuaries established for wild animals which in turn has dwindled the areas covered by them.
2. This has resulted in diminishing of grazing areas available to all wild animals, particularly wild elephants.
3. Due to diminishing grazing areas in sanctuaries, wild elephants are compelled to find alternate food sources outside. This inevitably means crops in home gardens and other cultivations
4. Easy accessibility for elephants into human habitations bordering these reservations.
As a solution to all these issues a course of action as set out below is proposed. It is based on studies of wild elephant movements in Africa where it has been established that elephants cannot or avoid climbing or descending deep slopes. It has been generally observed that Sri Lankan elephants too exhibit this behaviour.
To deal with factor No 4 mentioned above, it is proposed to dig trenches preferably 6ft deep and 8ft wide along the perimeters of these reservations, where the terrain is generally flat. Earth excavated in digging these trenches should be used to make machine compacted bunds about 6ft high and 8ft wide, on the village side of trenches. These bunds should be constructed in such a way so that their sides facing sanctuaries are vertical and flush with the village side of trenches.
This will make the trench and bund combination a formidable barrier of about 12 ft. high from the bottom of trenches to prevent elephants crossing into cultivated areas. To provide escape routes for animals accidently falling into these trenches pathways about 7ft. wide and of about 20 degrees slope could be excavated into reservations at intervals between 50 to 100 metres. This earth excavated too could be used to further broaden the bunds. If the top surfaces of these bunds are tarred, they could serve as roadways for small vehicles to enable patrolling of bunds as well as minimise erosion, added benefits.
Where the land bordering sanctuaries slope upward or downward towards cultivated areas at angles of around 8 degrees or more, a slightly different strategy could be implemented. Where land slope down on to cultivated areas, earth along the borders on the cultivated side could be excavated to form vertical or almost vertical embankments, at least 7ft high. In sections where land slope down on to sanctuaries, earth on the sanctuary sides could be excavated to form nearly vertical embankments at least 7ft deep. Earth excavated to form embankments can be utilised to form machine-compacted bunds on top of embankments thereby further increasing their heights.
It is expected the formation of a system of trenches, bunds and embankments will minimise or even eliminate elephants foraging into cultivated areas. Other benefits of these hard-to-penetrate boundaries would be that they will serve as deterrents to human encroachments, illicit logging as well as poaching within sanctuaries. Hence the proposed plan of action will provide a common remedy to issues identified as 1 and 4 above.
Since wild elephants could be fairly well confined to sanctuaries by this strategy, it will become incumbent upon us to ensure that adequate food and water are provided to supplement resources within sanctuaries. For this purpose elephant feeding and watering sites (pools) could be constructed within the sanctuaries at suitable locations close to trenches. These pools could be lined with concrete to prevent seepage and should be designed to blend with their immediate surroundings. Water for pools could be pumped from what is collected in the trenches during rainy seasons. It would be feasible to locate these pools/feeding sites adjoining trench sections where rain water is bound to collect. Provision should also be made to pump water into pools from outside, when water in trenches run out.
Agricultural waste such as harvested banana trees, corn plants, sugar cane bagasse, paddy straw etc., from cultivations around these locations could be purchased to be used as elephant feed. In addition fast growing grasses and other plants such as gliricidia could be grown in marginally fertile land to supplement feeding material referred to above, providing additional sources of income for villagers around these locations. These feed items could be delivered from the viewing sites to feeding/watering sites by conveyor belts eliminating the need for food handlers to enter sanctuaries. The procedures followed by the Pinnawela Elephant Orphanage to procure feeding material could be adopted where feasible. Hence it is seen that feeding elephants in this manner will resolve the issues referred to at 2 and 3 above.
The pools can be stocked with suitable varieties of fish which will hinder breeding of mosquitos and also attract water birds to feed on them. Locating bird feeding sites stocked with suitable types of grain would attract other wild birds such as peacocks, jungle foul, parrots etc.
As it is expected that elephants and even other animals and birds would be drawn to these feeding sites, viewing platforms could be constructed on the cultivated side in close proximity to feeding sites. Since generally, elephants are the favourite attraction for wildlife enthusiasts, it is expected that they would come to these sites for viewing elephants, causing least disruption to elephant habitats. This in turn could make these sites income-generating ventures and also ease high visitor pressure on wildlife sanctuaries. To encourage people to patronise these sites, entrance fees into wildlife sanctuaries could be substantially increased while charging a much lower rate of fees to viewing sites.
When the number of people who patronise these sites increase, they will attract categories of business enterprises such as restaurants, curio shops, sale points selling approved feeding materials. This would enhance the value of land holdings in the neighbourhood and also generate new employment avenues as had occurred around the Pinnawela Elephant Orphanage.
Since construction of trench, bund and embankment systems would involve mainly earthworks, imported material costs would be minimal. Major cost factors will be for equipment (which may be already available in our country), fuel for machinery and labour. Here labour will mean generation of thousands of jobs ranging from engineers and earth-moving machine operators to unskilled labourers. Since a project to secure all sanctuary boundaries as explained above may take about 10 years to complete, it will ensure fairly long-term employment for those engaged in the project. This is yet another benefit.
As the project as outlined above could be the most effective way to resolve the human elephant conflict and will also contribute towards conservation of the rich bio-diversity within our sanctuaries it could qualify to receive funding from the Rs. 4000 million allocated for the purpose, in the 2016 budget. As human elephant conflicts have become a serious issue and this project will be a pioneering way of resolving these conflicts, it may be possible to secure funding from organisations such as the World Wildlife Fund and other organisations dedicated to save wild elephants from extinction.