Western Ghats

Description

Stretching like a mountainous spine down the western edge of India, the Western Ghats are a unique mountain range that harbours an incredible diversity of flora and fauna ^{(1) (2)}. Although most of the Western Ghats appear more like rolling hills than craggy snow-covered peaks ⁽²⁾, parts of it do reach over 2,000 metres and it contains the highest mountain in India, the Anaimudi, at 2,695 metres ⁽³⁾.

The peaks of the Western Ghats intercept the south-western monsoon winds ⁽¹⁾, which bring heavy rain between June and...

Western Ghats fact file

• Description
• Range
• Biodiversity
• Threats
• Conservation
• Find out more
• Glossary
• References

Description

Stretching like a mountainous spine down the western edge of India, the Western Ghats are a unique mountain range that harbours an incredible diversity of flora and fauna ^{(1) (2)}. Although most of the Western Ghats appear more like rolling hills than craggy snow-covered peaks ⁽²⁾, parts of it do reach over 2,000 metres and it contains the highest mountain in India, the Anaimudi, at 2,695 metres ⁽³⁾.

The peaks of the Western Ghats intercept the south-western monsoon winds ⁽¹⁾, which bring heavy rain between June and September ⁽¹⁾. An astonishing 2 to 8 metres of rain drench the Western Ghats each year, most of it falling in the short monsoon period ⁽⁴⁾. These rains feed dozens of rivers that originate in the mountains ⁽¹⁾, and flow down into India, providing drinking water, irrigation, and power for approximately 245 million people ^{(1) (4)}.

The rainfall patterns in the Western Ghats not only sustain the livelihoods of millions, but, coupled with the region’s complex geography and temperature gradient (from over 30 degrees Celsius at sea level to 0 degrees Celsius at the highest parts ⁽⁵⁾), produces a great variety of vegetation types ⁽¹⁾.

Scrub forests on the low-lying, drier, eastern slopes give way to deciduous and tropical rainforests that occur up to about 1,500 metres ⁽¹⁾. Above this elevation, a mosaic of rolling grasslands and montane cloud forests (locally called ‘shola’) blanket the Ghats ^{(1) (6)}. The Western Ghats also contain savannas; peat bogs, where grasses, sedges and mosses flourish in areas of high rainfall over 2,000 metres; and Myristica swamps, a freshwater wetland unique to the Western Ghats found between sea level and 600 metres ⁽⁴⁾.

This incredible variety in vegetation types gives rise to an astonishing diversity of fauna. Although the Western Ghats cover less than 6 percent of the land area of India, it contains more than 30 percent of the country’s mammal, bird, reptile, amphibian and fish species ⁽⁴⁾, and many animals are still being discovered ⁽⁴⁾.

Range

The Western Ghats run 1,600 kilometres from just north of Mumbai, south through the states of Maharashtra, Goa, Karnataka and Kerala before petering out in Tamil Nadu, close to the southern tip of the Indian peninsula ⁽⁷⁾. Most of the Western Ghats run parallel to the coast, 50 to 80 kilometres inland from the Arabian Sea ⁽³⁾. This mountainous range covers an area of about 160,000 square kilometres ⁽¹⁾, and is broken only by the Palghat Gap, a 302 kilometre wide gap in the Western Ghats ^{(6) (8)}.

Biodiversity

Plants

Over 5,000 different plants occur in the Western Ghats. Around 1,700 of these are found nowhere else in the world ⁽¹⁾.

This includes the wild relatives of many economically important species, such as grains (including rice and barley), fruits (mango, banana and jackfruit), and spices (black pepper, cinnamon, cardamom and nutmeg) ⁽⁴⁾, as well as numerous medicinal plants ⁽⁴⁾, such as the highly threatened white damor (Vateria indica). The fragrant resin and seed oil of this large evergreen tree can be used in medicines, as well as in soap and candle manufacturing ⁽⁹⁾.

Other notable plants that occur in the Western Ghats include Wight’s sago palm (Arenga wightii) whose starch and sap (palm wine) provides an alternate source of food and drink for the local Muthuvans tribes ⁽¹⁰⁾, and Cycas circinalis, an endangered cycad ⁽¹¹⁾ that plays an important role in the ecosystem. Not only does this cycad host the plains cupid butterfly (Edales pandava), but it is also thought that fruit bats feed on its seeds, providing one of the few food sources in the forest during the monsoon season ⁽¹²⁾.

Mammals

Around 120 mammal species have been recorded in the Western Ghats ⁽⁶⁾. Most notably, they are home to both the world’s largest population of Asian elephants (Elephas maximus) and to ten percent of the world’s tigers (Panthera tigris) ⁽²⁾.

Prominent endemic mammals include the Nilgiri tahr (Hemitragus hylocrius), which can be observed on the cliffs and high, grassy plateaus, and the lion-tailed macaque (Macaca silenus) which inhabits the evergreen forest ^{(6) (11)}.

Nearly 50 of the mammal species found in the Western Ghats are bats ⁽¹⁾. This includes Salim Ali’s fruit bat (Latidens salimalii), remarkable for being the only species in its genus ⁽¹⁾.

Birds

A great diversity of birds have been recorded in the Western Ghats ⁽¹⁾, from the imposing Indian vulture (Gyps indicus) to the tiny blue Nilgiri flycatcher (Eumyias albicaudatus), and the stunning Indian peafowl (Pavo cristatus) ⁽¹³⁾.

Of the 500 bird species known from the Western Ghats, around 22 species occur nowhere else in the world ⁽⁶⁾. Many of these endemic species, such as the Nilgiri wood pigeon (Columba elphinstonii) and Nilgiri blue robin (Myiomela major), are considered threatened ^{(6) (11)}.

Reptiles and amphibians

The 225 species of reptiles recorded in the Western Ghats includes some fascinating and unique animals ⁽⁶⁾, such as the endemic Cochin forest cane turtle (Vijayachelys silvatica) ⁽¹¹⁾, the wonderfully named mugger (Crocodylus palustris), and the infamous king cobra (Ophiophagus hannah). A family of primitive burrowing snakes, the Uropeltidae, are also largely restricted to these mountain ranges ⁽⁶⁾.

Equally as intriguing are the 117 amphibian species found in the Western Ghats, of which 89 are endemic ⁽¹⁴⁾. This includes the peculiar-looking purple frog (Nasikabatrachus sahyadrensis), which was only recently discovered in the southern Western Ghats, and represents an entirely new genus ⁽⁶⁾.

Fish and invertebrates

The numerous rivers and streams that originate in the Western Ghats are home to a remarkable variety of fish. Of the 288 species recorded, 118 are endemic ⁽¹⁶⁾. This includes the Denison barb (Puntius denisonii), a pretty, stream-dwelling fish that is a popular species in the ornamental fish trade ⁽¹⁶⁾.

While knowledge on the invertebrate fauna of the Western Ghats is relatively poor ⁽¹⁾, the available information indicates that the Ghats harbour an abundance of diverse invertebrates, many of which are believed to be endemic ⁽¹⁾. For example, of nearly 140 tiger beetle species known from the Western Ghats, more than 100 are found nowhere else ⁽¹⁾.

An incredible 330 butterfly species have been recorded in the Western Ghats ⁽⁶⁾. One of these species, the Travencore evening brown (Parantirrhoea marshalli), can only be found in a small area of mid-elevation forest in the Ghats, where it flutters around reed patches at twilight ⁽¹⁷⁾.

Threats

This diverse biological haven is under tremendous pressure from a variety of human activities ⁽⁴⁾. Only a third of the Western Ghats still clings to its natural vegetation, and those remaining forests are highly fragmented and face the threat of increasing degradation ⁽⁴⁾.

Selective logging, conversion of land to agriculture, and clearance for the construction of reservoirs, roads and railways have all played a part in this habitat loss ⁽¹⁾. Unfortunately, not even protected areas are safe from such threats, as hunting, firewood extraction, timber felling and livestock grazing apply pressure on the fringes of these important refuges ^{(1) (6)}.

As the already large human population in the region grows further, the pressures on the remaining habitat of the Western Ghats will only increase. Conflict between humans and wildlife is already apparent, as raiding elephants may be killed in an attempt to prevent further crop loss ⁽¹⁾.

Conservation

Around 9 percent of the Western Ghats is protected, within 20 National Parks and 68 Sanctuaries ⁽⁶⁾. In addition, the Indian Forest Conservation Act, enacted in 1980, resulted in the cessation of all legal logging operations in the Western Ghats in the mid-1980s ⁽¹⁾. While this offers the biodiversity of the Western Ghats some protection, it is clear that, as the human population pressure increases, further conservation measures are required ⁽¹⁾.

Currently, many of the critical habitats within the Western Ghats, such as lowland dipterocarp-dominated evergreen forests and Myristica swamps, are not adequately represented in protected areas ⁽⁶⁾. Identifying, and subsequently conserving, key areas of biodiversity within the Ghats will help ensure that more of its flora and fauna are protected ⁽¹⁾. India’s National Wildlife Action Plan 2002-2016 focuses on strengthening and enhancing this protected area network, and recognises the importance of local community participation in protected area management ⁽⁴⁾. It also addresses the need for ‘conservation corridors’, to connect protected areas ⁽⁴⁾ and allow the movement of wide ranging species such as the Asian elephant (Elephas maximus), tiger (Panthera tigris), and dhole (Cuon alpinus) ⁽¹⁾.

Luckily, India has a long history of conservation and a reverence for nature, with a number of government institutions and non-governmental organisations actively involved in wildlife conservation. This will become increasingly important as the country tackles the challenge of strengthening conservation efforts in the face of the expanding human population ^{(1) (4)}.

Find out more

Learn more about conservation efforts in the Western Ghats:

• Earthwatch – India Regional Climate Center: www.earthwatch.org/rcc_india
• Western Ghats Conservation Society: www.westernghats.org
• Conservation International: Biodiversity Hotspots – Western Ghats and Sri Lanka: www.biodiversityhotspots.org/xp/hotspots/ghats/Pages/default.aspx
• WWF – Western Ghats: wwf.panda.org/what_we_do/where_we_work/western_ghats/
• Wildlife Conservation Society – Western Ghats: www.wcs.org/saving-wild-places/asia/western-ghats-india.aspx

Glossary

Biodiversity

short for biological diversity, biodiversity is a term used to define the great diversity of life on Earth, or more specifically, in a particular habitat or ecosystem.

Cloud forest

a tropical mountain forest, with a high incidence of cloud cover throughout the year.

Deciduous forest

forest consisting mainly of deciduous trees, which shed their leaves at the end of the growing season.

Dipterocarp

trees of the family Dipterocarpaceae: resinous trees that are found in the old world tropics.

Endemic

a species or taxonomic group that is only found in one particular country or geographic area.

Genus

a category used in taxonomy, which is below ‘family’ and above ‘species’. A genus tends to contain species that have characteristics in common. The genus forms the first part of a ‘binomial’ scientific species name; the second part is the specific name.

Invertebrates

animals with no backbone, such as insects, crustaceans, worms, molluscs, spiders, cnidarians (jellyfish, corals, sea anemones) and echinoderms.

References

1. Conservation International: Biodiversity Hotspots – Western Ghats and Sri Lanka (March, 2011)
   http://www.biodiversityhotspots.org/xp/hotspots/ghats/Pages/default.aspx
2. WWF – Western Ghats (March, 2011)
   http://wwf.panda.org/what_we_do/where_we_work/western_ghats/
3. Kohli, M.S. (2002) Mountains of India: Tourism, Adventure and Pilgrimage. Indus Publishing Company, New Delhi.
4. Bawa, K.S., Das, A., Krishnaswamy, J., Karanth, K.U., Kumar, N.S. and Rao, M. (2007) Ecosystem Profile: Western Ghats and Sri Lanka Biodiversity Hotspot - Western Ghats Region. Critical Ecosystems Partnership Fund, Virginia.
5. Dahanukar, N., Raut, R. and Bhat, A. (2004) Distribution, endemism and threat status of freshwater fishes in the Western Ghats of India. Journal of Biogeography, 31(1): 123-136.
6. Gunawardene, N.R., Dulip Daniels, A.E.., Gunatilleke, I.A.U.N., Gunatilleke, C.V.S., Karunakaran, P.V., Geetha Nayak, K., Prasad, S., Puyravaud, P., Ramesh, B.R., Subramanian, K.A. and Vasanthy, G. (2007) A brief overview of the Western Ghats –Sri Lanka biodiversity hotspot. Current Science, 93(11): 1567-1572.
7. Gupta, O. (2006) Encyclopaedia of India, Pakistan and Bangladesh. Isha Books, Delhi.
8. Ahmad, A. (2009) Geography of the South Asian Subcontinent: A Critical Approach. Concept Publishing Company, New Delhi.
9. Appanah, S. and Turnbull, J.M. (1998) A Review of Dipterocarps: Taxonomy, Ecology, and Silviculture. Center for International Forestry Research, Bogor Barat, Indonesia.
10. Manithottam, J. and Francis, M.S. (2007) Arenga wightii Griff. – A unique source of starch and beverage for Muthuvan tribe of Idukki district, Kerala. Indian Journal of Traditional Knowledge, 6(1): 195-198.
11. IUCN Red List (March, 2011)
    http://www.iucnredlist.org/
12. Saneesh, C.S. and Varghese, A. (2007) Mutualistic relationships involving the endemic Cycas circinalis L.: Field notes from the Appankappu Forests, Nilambur, Kerala, India. The Cycad Newsletter, 30(4): 28-29.
13. BirdLife International (March, 2011)
    http://www.birdlife.org/
14. Ranjit Daniels, R.J. (1992) Geographical distribution patterns of amphibians in the Western Ghats, India. Journal of Biogeography, 19(5): 521-529.
15. Molur, S. (2008) South Asian amphibians: taxonomy, diversity and conservation status. International Zoo Yearbook, 42: 143-157.
16. Raghavan, R., Prasad, G., Anvar A.P.H. and Sujarittanonta, L. (2007) ‘Boom and bust fishery’ in a biodiversity hotspot – is the Western Ghats loosing its most celebrated native ornamental fish, Puntius denisonii Day? Current Science, 92: 1671-1672.
17. Kalesh, S. and Prakash, S.K. (2009) Early stages of the Travancore evening brown Parantirrhoea marshalli Wood-Mason, 1880 (Satyrinae Nymphalidae, Lepidoptera), an endemic butterfly from the southern Western Ghats, India. Journal of Bombay Natural History Society, 106(2): 142-148.