But a non-native creeper called Mikinia Micrantha that locals have aptly named as Banmara or forest killer, has been out destroying the jungles of the sanctuary, posing a serious threat to its exceptional wildlife.[break]
Placed at number two in the world’s most notorious weed list, the wild creeper is also known as Mile-a-Minute for its ferocious growth rate of an inch a day.
Besides, a single plant can produce up to 40,000 seeds annually which further aids in its exponential growth.
Chanda Rana, founder of Save the Environment Foundation (SEF), who also made the documentary “Mile a Minute: A Serious Threat to CNP” says that the weed has already covered more than 20 percent of the park and affected one third of the prime rhino habitat in the sanctuary.
“Not only has it affected the swamp areas where most rhinos live, it has also deprived them of their food source which will have a negative impact on their population,” says Rana.
She explains that the creepers grow over the grasslands or host plants, including small bushes to big trees and form a canopy, depriving the host plants of sunlight and slowly killing them.
The locals interviewed in her documentary say that banmara is not a preferred food source for herbivores and their cattle refuse to eat it.
Though there have been sightings of rhinos consuming the weed, conservationists says it is nutritionally deficient for proper growth of rhinos that require a large intake of nutrient-rich vegetation.
“As the vine isn’t a native plant, it’s natural that the animals here don’t prefer it,” says Dr Narendra Man Babu Pradhan, conservation biologist at WWF, Nepal. “For rhinos, who feed on tall grasses in the riverine forests, the vine is definitely not a staple food and it’s actually suppressing growth of such native plants. However, we’re yet to have a clear report on the effects of mikinia on rhinos.”
Native of South America, mikania was first collected in Nepal in 1963 from Ilam, according to the IUCN report, “Mikania Micrantha Weed Invasion in Nepal.” The report states that Mikania was first used in India as a ground cover crop in oil and tea plantations.
Rana reasons that the weed was introduced to Nepal through either migratory birds but more probably through floods, as the infestation is seen more severe in riverine areas. Mikania infestation in CNP was also noted after the massive flood in 1990.
The weed invasion has once again put the rhino population in jeopardy at a time when their numbers have actually picked up from 372 in 2005 to 534 in 2011 as a result of encroachment and poaching controls.
Moreover, she stresses that the impact of the foreign infestation will affect not just the rhinos but the entire eco-system of the reserve if measures are not taken to control the infestation.
The infestation control, however, isn’t an easy task.
“We could uproot these plants but the chances of seed dispersal are very high which could further escalate the problem. Trying to completely destroy the plants using pesticide would also not be feasible in the forest as it can harm surrounding vegetation and wildlife too,” says Dr Dharma Raj Dangol of Institute of Agriculture & Animal Sciences in Rampur, Chitwan.
Besides, Pradhan mentions, “WWF has been studying its effect under the rhino habitat management program. However, the creeper has already overtaken more than 200 sq. km of CNP and manual uprooting of that entire vine isn’t a joke. It also proves too costly.”
He adds there are researches going on in India that hint that a certain Puccinia rust fungus can control its growth but it’s yet to be tested to see it’s actually a feasible method for the reserve and its ecosystem.
On the other hand, Naresh Subedi, Research Officer at Natural Trust for Nature Conservation (NTNC), says that the need now is to focus more on tests and experimentation of control methods rather than jumping into hasty decisions.
“We’re working in collaboration with researchers in Assam, India, where the Puccinia fungus has been released to control Mikinia. Furthermore, this is not just a problem seen here but in some 25 countries. We need to analyze the reports and check if the method can be feasible here,” he says.
What has to be done immediately, though, according to Subedi is to have an awareness campaign so that mikinia which has now also been spotted in Dang does not spread into western wildlife reserves such as Suklaphanta and Bardia.
“If there are such sighting and people are aware of it, it’s a lot easier to control it during the earlier phases,” he says.
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