Nilgiri Tahr become locally extinct in 14% of historic shola-grassland habitat, revival efforts on
CHENNAI: The Nilgiri Tahr, whose ecological and cultural significance dates back to the late Mesolithic period (Middle Stone Age), is today in peril. Historically present in much of the Western Ghats, the Tahr inhabits only a few scattered habitat patches within Tamil Nadu and Kerala and is restricted to a mere 5% area of Western Ghats within a narrow stretch of 400 km between the Nilgiris hills in the north and Asambu hills in the south.
As per the latest study done by WWF-India in association with the Tamil Nadu forest department, the ‘Mountain Monarch’ has become locally extinct from around 14% of its historic shola-grassland habitat within the past few decades. To reverse this trend, the Tamil Nadu government is contemplating major conservation interventions. Chief Minister M K Stalin launched the Nilgiri Tahr Project earlier this week.
The study says there are 123 habitat fragments ranging in area from 0.04 sq,km to 161.69 sq.km totalling to an area of 798.60 sq.km with the confirmed occurrence of Nilgiri Tahr. Among these, there are 20 fragments where the Tahr is locally extinct.
Based on the latest species distribution data and the known connectivity and habitat suitability, the entire species range is divided into five conservation blocks — Nilgiri Hills; Siruvani Hills; The High Ranges and Palani Hills; Srivilliputhur, Theni Hills and Tirunelveli Hills; and KMTR and Ashambu Hill. Some of these blocks are only tenuously connected, while others have no connectivity due to the presence of anthropogenic or natural barriers, including roads, plantations, settlements, rivers and dense forests.
has been bunched into five conservation blocks
in TN and Kerala.
The Nilgiri Tahr Project
Since the Nilgiri Tahr’s distribution is already scattered and limited to five blocks, it is important to conserve the existing habitat and to establish the connectivity within and between blocks through land use planning and habitat restoration. Tamil Nadu Chief Wildlife Warden told TNIE: “This is a five-year project with several short and long-term goals. To start with, we are gearing-up for the first synchronised census in coordination with the Kerala forest department to get the current population, identify conservation challenges etc. Also, habitat improvement and restoration will kick-start. Next, we will radio collar a few individuals, which would be first-of-its-kind for any mountain ungulate in India, to get more information on animal movement, behaviour and home range.”
On re-introduction of the Tahr in historic habitats, Reddy said it can’t be done immediately. As part of the Tahr project, habitat viability and risk assessment will be done. It will take at least a couple of years for this exercise. One area WWF-India suggested for pilot re-introduction was Glenmorgan mountains in the Nilgiris that used to be the original habitat of the Tahr. However, the small herd present here appears to have become extinct a few decades ago.
“WWF India had done a habitat assessment of the Glenmorgan area in the Nilgiris to know the potential to reintroduce the Tahr to this historical site to begin with. If successful, plans for reintroduction at other locally extinct sites can be chalked out. There is a herd from the Western catchment area of the Mukurthi National Park that is semi-habituated for human presence. A few individuals from this herd can be reintroduced to the Glenmorgan hills. These reintroduced populations would be extensively monitored to understand the adaptation and challenges in the process. This understanding would help refine future reintroduction plans,” WWF-India informed the Tamil Nadu forest department in its assessment.
Ecological importance
Experts say the Nilgiri Tahr is a generalist in food habits and has been observed to feed on around 120 species of plants, including grasses, herbs, shrubs, leguminous plants and a few tree species. Grazing and browsing by Nilgiri Tahr contribute to maintaining essential ecosystem processes through nutrient recycling in the high altitude shola-grasslands system, which are one of the most threatened ecosystems worldwide. The shola-grassland ecosystems, which occur at an elevation band between 1,400 and 2,700 m, store most of their carbon underground in root systems and soil.
Studies also show tussock grasses such as Chrysopogon nodulibarbis, Themeda triandra, Andropogon polyptychus and Dichanthium foulkelsii, can sequester large amounts of carbon in soil. In fact, grassland and shrubland restoration are key to climate resilience and are more reliable carbon sinks than forests, because all carbon storage happens below the ground surface. “So, it is vital that we protect and sustain a good population of Nilgiri Tahr to allow the grassland and shrubland to do their climate job. Within a month, we will be conducting a symposium in Coimbatore where all experts will be invited to help us draw a roadmap for Nilgiri Tahr Project,” Additional Chief Secretary Supriya Sahu to govt, Environment, Forests and Climate Change Dept, told TNIE.
Fragmented populations
As per the last assessment done in 2015, there are 3,122 Nilgiri Tahr in wild in Tamil Nadu and neighboing landscapes of Kerala. Except for the large herds in the Nilgiris and Anamalai Hills, other populations are fairly small from single digit to less than 100 individuals and isolated. Many of these habitats exists outside Protected Areas and have been getting further fragmented due to linear infrastructure, plantations and the spread of exotic plant species. Conservationists warn there is high probability of local extinctions of these isolated population.
This makes Niligir Tahr Project all more important considering it aims to stabilise and grow the current populations and pave the way for further range expansion by the species.