Rising waters a threat to Thekkady ecosystem

Giji K. Raman
KATTAPPANA,  
The Hindu, November 20, 2014 

The rising waters in the Mullaperiyar reservoir could pose a threat to wildlife and the ecosystem as hundreds of hectares of land, where a semi-forest system has developed, are now under water.

The tree stumps in the lake, often described as a landmark of Thekkady, are habitats of hundreds of birds, including migratory ones. With many already under the water, the impact is believed to be on a wider scale than what was expected, R. Sreehari, ecologist, Periyar Tiger Reserve, said.

Data compilation

Mr. Sreehari said they were compiling data on the total land under the water, disturbances to the habitat, and long-term impact on wildlife and the ecosystem.

“Now, with a majority of the tree stumps under the water, the nestlings of Great Cormorant (Phalacrocorex carbo), little cormorant (Microcarbo niger), oriental darter (snake birds) and various kingfisher species are the first affected.

These birds feed on fish and prefer treetops, cliffs on the lake, or waterbodies for nesting and breeding. As they are resident species, it will take a long time to rebuild the disturbed nesting places. Visitors to Thekkady would have a picture of these birds and their nesting on undisturbed tree stumps, which are now beneath the water.”

Herbivores were also highly affected, Mr. Sreehari said.

Elephant corridors

Elephant corridors in Ayyappankurukku and Edappalayam were now in the waterlogged areas, he said. With disturbances to their natural habitat, including bamboo groves, there were chances of the elephants straying out of the area, he said.

There was damage to butterfly species and rare orchids too, he said.

For the past 35 years, a sub-forest had developed in the area and it was now under water, with the water level in the Mullaperiyar dam nearing 142 ft. How long it would take to restore the lost flora and fauna was being studied, in addition to habitat disturbances to the wildlife in the long run, Mr. Sreehari said.

 

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Periyar trout facing extinction

Giji K. Raman
KATTAPPANA,
The Hindu,September 17, 2014 

Brahmanakendai (Lepidopygopsis typus), a freshwater fish species in the family of cyprinidae, endemic to the Mullayar tributaries in the Western Ghats, is under threat of extinction due to habitat disturbance and introduction of hybrid varieties such as tilapia and common carp in the Thekkady lake. The species is also known as Periyar trout as it is endemic to the waters there.

The fish which is already on the red category list of the International Union for Conservation of Nature (IUCN) could be in more danger as nearly 80 per cent of its total population was endemic to the Periyar Tiger Reserve (PTR) where the African Catfish proves a threat to its existence, say experts.

According to Rajeev Raghavan, IUCN South Asian Co-chair, the fish species was once considered to be in the Schizothoracinae family as it was physically similar to the Snow trout found in high altitude streams. Recent genetic tests, however, grouped it in cyprinidae family.

The species is found in flowing waters and lay eggs in deep waters. It was once a main diet of the Mannan tribe. The name Brahmanakendai may be due to a thread, similar to a ‘poonool,’ in its body, says conservation researcher Anvar Ali.

He says that studies by the Kerala Forest Research Institute in 1999 and individual studies later pointed to high level of survival threat on the species in its natural habitat.

This is one of the 63 species endemic to the Western Ghats’ southern region. It was first reported by Divan Bahadur Sundararajan in the tributaries of the Periyar and the Mullayar and in the portions the streams join the Thekkady lake.

Mr. Ali says that there has been no scientific study on the impact of the hybrid varieties of fish introduced in the Thekkady lake on the endemic species.

Brahmanakendai faces extinction threat as there is high stress on the waters due to competition for food and existence threat raised by the African Catfish. The species has many specialities and unique features and considering the high threat on its survival, a plan of action to protect it in its natural habitat needs to be implemented, he says.

 

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There is more to PTR than tigers

Giji K. Raman
KATTAPPANA,  
The Hindu, February 6, 2011 

A Malabar pied hornbill in the reserve.

The Periyar Tiger Reserve (PTR) harbours a wide variety of migratory and endemic birds too, with various ornithological surveys in the sanctuary recording 323 species so far.

In a recent survey, nine new species, Spot-billed pelican, Pheasant-tailed jacana, Purple heron, Purple swamp hen, Western reef egret, Oriental white ibis, Common teal, Common moorhen and Common coot, were identified in the sanctuary

A. Veeramani, an ecologist at the Periyar Foundation, who keeps a record of the bird surveys here from 1993, says that though migratory birds here are less when compared to better known bird sanctuaries like Thattekkad, 14 species endemic to the Western Ghats are found in the PTR. An earlier survey had identified four new bird species — Common green shank, Malabar pied hornbill, Ashy-crowned sparrow lark and Chestnut-bellied nuthatch.

The avifauna of Periyar includes birds of prey (raptors), water birds, galliform birds, pigeons, woodpeckers and passerines. Cormorants and darters are numerous in the lake and woolly-necked storks and grey herons are found on the fringes of Thekkady Lake. Along with many common birds, the Great Hornbill, an endangered species, is common in the park.

The Western Ghats is known as an area of high avian endemism. Fourteen endemic species are reported from southern Western Ghats viz., Malabar grey hornbill, Nilgiri wood pigeon, Malabar parakeet, Crimson-fronted barbet, Rufous babbler, Nilgiri laughingthrush, White-bellied treepie, Black-and-orange flycatcher, flycatcher, White-bellied blue flycatcher, Broad-tailed grassbird, Nilgiri pipit, White-bellied shortwing and Crimson-backed sunbird. Except Nilgiri laughingthrush, all endemic bird species of Western Ghats are found in PTR.

‘Disjunct species' too

Besides the endemic species, the Western Ghats is home to certain ‘disjunct species,' which are found in the Eastern Himalayas too but are absent in between. They include Black baza, Rufous-bellied eagle, Great hornbill, Spot-bellied eagle owl, Sri Lanka frogmouth, Great eared nightjar, Dollarbird, Scaly thrush and Little spider hunter. All the disjunct species in the Ghats, except Grass owl and Oriental bay owl are found in the the PTR.

 

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