The foothills of the eastern Himalayas is one of the biggest strongholds of biodiversity in South Asia. Steep differences in altitude and climactic variations have given rise to great variation in vegetation types- with hillsides clothed in tropical deciduous forests, and wet grasslands making up the plains (though these have largely been lost as a result of centuries of development), which are watered by numerous rivers. This river-forest-grassland complex hosts numerous endangered species, some of which most people haven’t even heard of . One such species is a large heron, whose regal bearing and distinctive coloration has led it to being called the Imperial Heron, or the White-bellied Heron.
The Heron is a habitat specialist, with most studies indicating its preference for frequenting the banks of fast-moving mountain streams which flow through the East Himalayan foothills. It has been reported from altitudes of upto 1500 m. At times, it has also been sighted in marshes located in wet grassland patches. For nesting, however, it chooses tall trees located in subtropical forests, with isolated trees on riverbanks being particularly preferred. It preys on a variety of fish, amphibians and reptiles, which are grabbed from fast-flowing streams by seemingly near-impossible stabs of its agile bill.
Hunting the few, small, fast-swimming fishes of the hilly streams, however, is no easy task, and places great demands on nesting herons. The difficulty in procuring prey is probably a reason for this bird never having been particularly numerous or widespread. Currently, fewer than 250 herons survive, and, in view of the magnitude of the threats faced by this tiny population, IUCN (International Union for the Conservation of Nature and natural resources) upgraded the threatened status of the species to “Critically Endangered” in its Red Data Book.
Currently, the heron’s geographical distribution is restricted to three countries-Bhutan, India and Burma. Stray birds probably still make their way to north-eastern Bangladesh every now and then, though the last confirmed record of the heron’s presence there was in 1988. The largest populations are thought to occur in the Punatsang chu river valley in south central Bhutan, with breeding sites being reported from the banks of the Pho Chu river. The total number of herons in this landscape is thought to be about 30-50, though only a small proportion are regularly sighted.
In India, white bellied herons have historically been reported from Bengal, Assam and Arunachal Pradesh. However, their continued existence in Bengal is doubtful, with few confirmed records since the 1950’s. In Assam, they have been reported from the Manas Tiger Reserve, Pobitora Wildlife Sanctuary, Kaziranga NP, and Dibru Saikhowa NP, with occasional historical records from outside protected areas, such as the Sadiya forests(which reported several breeding pairs between 1922 and 1930).
They are most frequently sighted in Manas, in patches of subtropical forest bordering the Manas river, and its tributaries, the Beki and the Bholkaduba.
Several key habitats of the heron lie in Arunachal Pradesh, with the Deban and Noa-Dihing rivers in Namdapha being their chief stronghold. It is here that a ZSI survey succeeded in finding the first nest of this critically endangered heron outside Bhutan, in 2014. A detailed study by Gopinathan Maheswaran, however, found that even this key habitat probably has no more than 6-8 herons in all. Though the 1,985 sq. km Namdapha has low levels of human disturbance in its interior parts, large-scale hunting by the Lisu tribe based in Gandhigram has severely depleted the populations of most species of mammals and birds in the reserve.
Besides hunting, other factors which contribute to the endangerment of Namdapha’s white-bellied herons include fishing in the Noa-dihing river and the movement of villagers between Gandhigram and Vijaynagar. Its nesting patterns are likely to be adversely impacted by such human activities.
And these are just a few of the threats which this species has to confront throughout its ever-shrinking range. The fast-flowing rivers, which the heron is greatly dependent upon, are also seen by the developers of India and Bhutan as a great way of generating hydroelectric power. Bhutan aims at generating about 10,000 MW of hydel power from the heron’s chief stronghold in Punatsang Chu, by 2020. Surveys by the Bhutanese government and NGOs involved in wildlife conservation has indicated a marginal decline in nesting, as well as overall heron populations since 2009, indicating that the species is not safe even here. The construction of dams, irrigation canals and power-houses is likely to cause a significant amount of habitat destruction, while altering the delicate riverine ecology. Any adverse impact on fish populations and breeding patterns is likely to hit heron nesting hard.
Likewise, the Indian Government has also invested greatly in developing infrastructure for hydel power in the ecologically fragile Northeast. Billed as India’s “future powerhouse”, as many as 168 large hydel projects are slated to be constructed there, with a total generating capacity of 63,328 MW.
The Brahmaputra, the lifeline of the region, will be dammed, as will many of its tributaries, such as the Subansiri, Siang and Dhansiri. The resulting impact on heron habitat and ecology, both in the foothills, as well as further downstream, is likely to be severe.
Moreover, large-scale clearing of lowland forests in Assam’s Sonitpur, Udalguri, Darrang, Baksa has compounded the unfolding ecological disaster. The political violence of the 90’s encouraged massive encroachment of what was once vibrant habitat for elephants, tigers and White-bellied herons. The timber mafia operated with impunity, as the entire 81 sq. km Charduar was taken over by encroachers in the late 90’s, with not a single tree left standing. Other tracts, such as Balipara RF, which forms the buffer of Nameri Tiger Reserve, Biswanath RF and Sonai Rupai Wildlife Sanctuary, also suffered greatly.
Even critical wildlife habitat, located in the heart of Tiger Reserves has not been spared misery, with a 4 sq. km of the Bhuyanpara range having been encroached upon. Ultapani and Kachugaon Reserve Forests, located in the buffer of Manas, has also seen large-scale encroachment and consequent clear-felling in the recent past.
These ecological disasters have placed the White-Bellied Heron, and its fellow critically endangered denizens of the forests of the region in great peril.
Several conservation actions have been initiated to pull the herons back from the brink. The chief conservation actions involved include the protection of heron habitat, and the monitoring of its populations and nesting sites. Paucity of information regarding the heron’s ecology and its status is a major stumbling block as far as conservation is concerned, and in 2007, IUCN called upon range states to do more in this regard. One of the most significant is one that started in Bhutan in 2003, spearheaded by the Royal Society for the Protection of Nature (RSPN), Bhutan, and backed by the World Wildlife Fund, the Felburn Foundation and the International Crane Foundation.
This project has been monitoring Punagstang Chu’s herons assiduously ever since, and among its highlights was the hatching of a White-Bellied Heron in captivity for the first time in May 2011. In September, it was released into the wild. The project also aims to spread awareness among forest-dwellers regarding the plight of the heron, besides attempting to engage with key stakeholders such as developers, forestry officials.
A conservation project for White-Bellied Herons has also been taken up in Manas Tiger Reserve, led by NGOs ATREE (Ashoka Trust for Research in Ecology and the Environment) and Nature’s Foster, with the help of the IUCN . Several villagers, living in the landscape, who have been designated as “Heron Guardians” are playing an active role in spreading awareness among fellow villagers, besides monitoring heron populations and habitat.
In 2007, New Horizon, another NGO closely involved in White-bellied heron conservation in the Manas landscape, succeeded in rescuing and releasing a heron that had been captured by a Bodo villager in the Koilamola range. Nature’s Foster also reported sightings of the heron from the Subankhata RF in 2013, and efforts are underway to secure the help of the autonomous BTC (Bodo Territorial Council), under whose jurisdiction Subankhata falls, to conserve the forest patch for White-Bellied Herons and other endangered species of wildlife.
Tigers, elephants and rhinos may dominate the conservation discourse, but there is a great need to secure entire ecosystems, with a focus on lesser-known and studied species such as the White-Bellied Heron as well.
Above everything, the large-scale dissemination of awareness regarding the heron’s plight is the need of the hour, to ensure that it doesnt meet the same fate as the dodo. The conservation of this species, and its fragile habitat, will ensure the safeguarding of the water resources of Northeastern India, on which millions of people depend.