Human activity disturbs quiet habitat of black-necked cranes in Arunachal Pradesh

Locally known as Thung Thung Karmu, the black-necked crane (Grus nigricollis) is not simply a bird but an emotion for the inhabitants of Sangti and Zemithang valleys in Arunachal Pradesh in northeast India. It is deeply tied with the region’s folklore and it is believed to be connected with the incarnation of the Sixth Dalai Lama in neighbouring Tawang among the Monpa tribes. In 2017, a few monks from the Tawang Monastery visited Zemithang (which is located about 90 kilometres within Tawang) to register their protests against the illegal mining activities that threatened the arrival of the black-necked cranes. The same year, two birds also died of electrocution when they hit high voltage wires. Three years later, there still remains a lot to be done.

The black-necked crane is enlisted as ‘near threatened’ in the IUCN (International Union for Conservation of Nature) Red List of Threatened Species. The global population is estimated (as of 2014) at around 10,000-10,200 individuals, roughly equivalent to 6,600-6,800 mature individuals. It prefers meadows, wetlands, marshes for breeding and nesting.

Though they haven’t found any hatchlings, the locals of Sangti and Zemithang Valley say that the black-necked cranes prefer the valleys as wintering habitats due to moderate temperatures. As far as breeding goes, the black-necked crane is known to breed in high altitude wetlands and marshes of the Tibetan Plateau (Tibet, Qinghai, Xinjiang, Gansu), Sichuan (China), and eastern Ladakh (India).

A study on the black-necked crane, conducted in the year 2014, showed a decline in the birds spotted in Sangti and Zemithang Valleys, during their non-breeding time. In Sangti Valley, there were 11 sightings of the bird in 2005-06 which came down to four sightings in 2014. Zemithang meanwhile had three sightings in 2009-10 which went up to seven sightings in 2010-11 and dropped to four sightings in 2014.

No more frequent sightings in winter

Pem Norbu Bomiyakpa, 30, a resident of Sangti Valley, says one winter about eighteen years ago the villagers saw as many as eight black-necked cranes in the paddy fields near his farm. “But the number of cranes visiting Sangti has declined to three or four individuals over the years. And their visit has become irregular. We don’t see the birds every winter.”

Locals and conservationists in the region attribute these developments to a plethora of factors: changing agricultural practices; climate change; and anthropogenic activities in the form of infrastructure development, expansion of settlements that create disturbances in the bird’s wintering habitats.

As a wintering site, the black-necked cranes mostly rely on paddy and wetlands. A study analysing the deteriorating former wintering sites of these cranes in Bhutan points out, “In traditional farming practices, fallen grains of barley and paddy are left in the fields after harvesting in early winter, and these were described as providing important food for cranes. With development, the land area under agriculture has declined, reducing food availability.”

For Sangti and Zemithang, changes in agricultural practices including a shift from paddy to maize cultivation, happen to endanger the habitat of this bird. Even in places like Ladakh where hillslope pastures are decreasing and locals are compelled to graze their yaks around paddy fields, there has been a depletion for food availability of the endangered bird.

Kamal Medhi, Landscape Coordinator, Western Arunachal, WWF-India informs Mongabay-India that changes in agricultural practices are contributing to the loss of the crane’s habitats in Arunachal Pradesh. “There is a gradual shift to horticulture crops that’s taking up on the hill slopes threatening the habitats of the bird. Subsequent usage of chemical fertilisers and river erosion could be deterring the bird from using certain habitats in Arunachal Pradesh,” he says.

Mukul Sharma, the headmaster of the Government Middle School at Sangti Valley who’s been living in the village since the early 1990s, speculates that there is a correlation between the shrinking of paddy fields and the decline in the number of cranes visiting the valley. “As population grows, the village is expanding closer to the paddy fields the cranes use as their winter habitat. And with people inching closer, the bird’s wintering site here no longer provide the quiet they require.”

With Sangti and Zemithang drawing an increasing number of tourists every year, the merrymaking activities that take place near the swift flowing streams to which the cranes frequent, have become another deterrent for the birds. “The crane’s wintering sites in Sangti and Zemithang have faced the problem in the recent years. The birds don’t prefer to come here due to the lack of quiet,” says Daniel Mize, a zoologist at Rajiv Gandhi University in Arunachal Pradesh. He further says that both Sangti and Zemithang are seeing a lot of construction works for various purposes which create loud noises. “The loud sounds of crushing stones and use of heavy machinery also discourage the cranes to stop by the valleys.”

“Due to a steep rise in human population, there is also a rise in free-ranging dogs which are not confined to their houses. Near wintering sites and rice fields, the dogs roam about and chase or disturb the birds. There’s no reported casualty due to this so far, but the disturbance is a factor for cranes not choosing to visit the site,” Mize tells Mongabay-India.

Sharma, who was also a member of the now-defunct Black-Necked Crane Conservation Committee formed in the Sangti in the 1990s to preserve the iconic bird, concurs and says that incidents of dogs chasing cranes have been witnessed in the valley.

Echoing Mize, The Arunachal Times journalist Tongam Rina—who wrote a series of reports on the black-necked cranes sited in Arunachal Pradesh—says that while the changes in wintering sites of the bird require further research, “it is mostly because of increasing human interference that the cranes are hesitant to land here. They seem to prefer the quiet high altitude wetlands in Bhutan to Arunachal.”

She adds that after years of the cranes not landing, the locals had approached the authorities figuring the foreseeable calamity.  “When two birds reportedly died due to electrocution after coming into contact with high-voltage wires a couple of years ago, the locals raised with the forest department. Similarly, during a recent landing season, the locals had stopped the sports department from carrying out paragliding activities near Sangti Valley,” Rina says.

Furthermore, she mentions that the National Green Tribunal had taken note of the Tawang monks raising their voices following which the Nyamjang Chu hydroelectric project (NJCHEP) did not take off. However, “The state needs to do more as sand mining still continues. The mining is done for local and commercial use. The wildlife agencies are trying but they have not been very successful. Community involvement is necessary too to stop mining at the landing stretch.”

Read more: Ladakh’s revered bird is under threat from human’s best friend – dog

Rising temperatures, human settlements and free ranging dogs

Sharma and multiple villagers in Sangti also identify the rise in temperature in the village over the past two decades as one of the key deterrents that may be pushing the cranes out of the valley.

A 2014 study by the Chinese Academy of Sciences published in Wetlands finds that degradation of high altitude wetland ecosystems due to climate change and anthropogenic activities in the Tibetan plateau is not only jeopardising the black-necked crane in the form of loss of indispensable habitats but also affecting its biological and migratory behaviour.

A migratory and reclusive species like the black-necked crane that thrives in critical landscapes are very sensitive to change and are less likely to adapt to sudden changes in the habitat, unlike the species that flourish in dynamic urban ecologies. Therefore, conservations say, preserving the high altitude wetlands is a key to the black-necked crane’s protection and survival.

Titash Choudhury, an anthropologist who studied the crane habitat sites in Tawang and was formerly with the WWF, explains: “Compare a crow in the city vs. the black-necked crane in high altitude wetlands. The crow will be highly adaptive to the ever-evolving city unlike the black-necked crane in reclusive high altitude wetlands. Any change in critical landscapes like high altitudes wetlands impacts the species population concerned—because it is very unlikely that the crane will be able to adapt to sudden changes like a crow in the city would.”

Banner image: Black-necked cranes. Photo by Aditya Laghate/Wikimedia Commons.