Keystone in Crisis
Text by Dr. Joyti P. Das
"We admire elephants in part because they demonstrate what we consider the finest human traits:
empathy, self-awareness, and social intelligence. But the way we treat them puts on display the very worst of human behavior." -Graydon Carter
Photo: Udayan Borthakur
The majestic Asian elephant, Elephas maximus, a keystone species is under considerable threat, almost everywhere. Currently the future of Asian elephant is bleak owing to human induced factors. The significance of the Asian elephant and the importance of its conservation was recognized by the Government of India in 1990 and few areas were declared as Elephant Reserves across the country. The concept of an 'Elephant Reserve’ differs in various ways from the much highlighted Tiger Reserve concept. Emphasis was given to managing these Reserves by maintaining the existing elephant corridors and allowing the animals free movement across large areas.
Large areas of intact contiguous forest are essential for elephants to move freely. Seasonal movement of elephant herds for food and space is a critical feature in their lifespan. Unfortunately, these areas are no longer available because of ever increasing human population. Connecting green way or corridors between traditional elephant habitats is the key in such circumstances. Properly maintained green ways will certainly facilitate free movement of herds and minimise their crop raiding tendency in the bordering human settlements. The concept of 'corridor viability' is a complex issue and depends the distance separating two small population. If the distance is less than 5 kilometers then the corridor need to be very broad. Just a 1 km wide corridor would be adequate for the elephants' movement. On the other hand if the distance is noticeably more, the width of corridor has to be about 4 kilometers. A green way may not be a very good habitat; it may be a monoculture plantation or even a degrade forest. The areas supporting elephant population should be large enough so that population viability is maintained and this will depend on the carrying capacity of the habitat. If one elephant needs an area of 5 km and a viable populationis 1000 elephants for long term survival, a total contiguous area of 5000 km should be reserved for them.
Photo: Udayan Borthakur
The immediate target is to prevent extinction over a relatively short period of time, say the next one or two centuries. Small populations are always vulnerable. For every species, there is a critical size below which there is very little chance of a comeback. Proper management and other measures may increase the number, but the lost genetic diversity will never return. Such a population may crash at any time. So our goal is to maintain the number way above the critical size so that their sustainability is maintained. Again, it is impossible to be completely sure that a population, whatever the size, will survive. That is why, we must say in probabilistic term; the minimum viable population is that which has a 95% or 99% chance of survival for a minimum of hundred years. For getting the exact viable population number, one should consider the demography and the genetic structure of the population, catastrophic fluctuations as well. This can be done theoretically using computer simulations. A population of over hundred individual animals, is more or less safe from extinction for the next hundred years due to chance fluctuations in births and deaths. But then what happens to those populations with less than a hundred? Should we pay no attention and write them off completely? Of course there is no easy way of solving these problems. If large enough habitat is available for a small elephant population, one way is to manipulate the habitat so as to increase their carrying capacity. These may include maintaining the forest and providing waterholes during dry seasons etc. And if the habitat is not sufficient then translocating few elephants to more secured habitats, is the only choice. In our country, however wholesale translocation is beyond imagination. Exchanging individuals among populations in order to maintain genetic variability is of course likely. Theoretically, the migration and breeding of even one individual per generation is ample of genetic variation in case of a small population. However for exchanging individuals among populations, it is necessary to understand the genetic profile of populations. Such information is not yet available. Research on elephant genetics is therefore of vital importance at present.
Ivory poaching is a serious threat in southern India and some other parts of the country. Besides proper patrolling in the forest, a good intelligence network system should work hand in hand to halt the trade. Currently, human-elephant conflict is a mega issue in our country. Unfortunately, this is making people antagonistic towards elephant conservation. Time has come to define new tactics to drive away crop raiders, apart from our existing traditional methods. The preferable approach should be to change the land use pattern, for example, not planting elephant's food crops in the fringe of elephant habitats. Experimentation with elephant repellent crops should also be encouraged. Only when these issues are addressed the co-existence of human with elephants can be anticipated.
About the Author:
Dr. Jyoti P. Das
The author is a senior biologist at Aaranyak, working on ecology of elephants in Northeast India. He has completed his PhD on Asian Elephants in Manas Landscape.