The huge imperious stone gray heron is nearing extinction in its habitat in the Himalayas. Inhabiting the waterbodies in the broadleaf forest in the mountainous foothills of the region, the white-bellied heron (Ardea insignis), favors pristine mountain streams and rivers.
A mere 50 of them are believed to exist, and the numbers are going down constantly. They once thrived in the Himalayan freshwater ecosystem. The white-bellied heron remains the most threatened of the species and is listed under the critically endangered category on the red list of the International Union for Conservation of Nature. It is also listed under the Schedule 1 category under India’s Wild Life Protection Act of 1972, the highest legal protection. The exact number varies, but it is evident that the numbers are falling with each passing day.
Birdlife International, a non-profit, has revealed that the bird is extinct in the Himalayan nation of Nepal and Bangladesh. The remaining few are limited to north Myanmar, Bhutan, and the northeastern part of India.
They Are Becoming Rarer And Rarer
The white-bellied heron is known locally as the Chubja in Bhutan. Close to half of the surviving birds are in this tiny nation nestled in the Himalayas. It also has the largest figure of actively breeding pairs.
Recent figures from Bhutan are also a cause for anxiety though. A survey in March this year by Bhutan’s Royal Society for Protection of Nature found only 22 white-bellied herons, three of them sub-adults. This showed a decline from the 2020 figures of 27 herons.
The shy white-bellied herons’ first sightings were in the Indian state of Arunachal Pradesh. It has a graceful long neck and a large dark grey body with a contrasting white throat, vent, and belly. It favors the rivers. It exists in the Manas National Park in the Indian state of Assam, and the Namdapha Tiger Reserve in Arunachal Pradesh.
They have been rarely sighted at high altitudes. Although, a couple was seen at an elevation of 4,000 feet in Walong in the Anjaw district of Arunachal Pradesh.
The worrying part of the study in Bhutan is that now white-bellied herons were not seen in the Mochhu and Pochhu basins in the central district of Punakha, home once to the oldest and the biggest population of the birds in Bhutan. The Mangdechhu basin and the Kurigongri basin, once favorite haunts of the birds also recorded no sightings.
There was also a decline in population in the Punatsangchu basin in Nangzhina and Adha, favorite nesting and feeding zones even a decade ago. White-bellied herons were spotted at the Chamkharchhu river basin, which has no developmental activity nearby.
Threats Factors For The White-Bellied Heron
The usual human factors like the expansion of agricultural activities, development of tourism, and the construction of dams and hydroelectric projects on the rivers have threatened the breeding activities of the white-bellied herons. The major threat remains the hydroelectric projects and related developments such as grid electrification.
Another major reason is overfishing that has depleted its food source and deforestation in the regions. Poaching of the magnificent birds continues to be a major threat. Fledglings have been found electrocuted in the past. The stagnation of numbers despite juveniles being detected has been attributed to juvenile deaths.
The genetic pool has shrunk to 5 breeding pairs. Forest ranger Damber Bahadur Chhetri with the Royal Manas National Park says that a couple of young white-bellied herons left their nest and made for the forests in Tsaidang. He had observed their habits for a month and said their affection for each other was heartwarming.
The white-bellied herons were photographed by the 4th king of Bhutan, Jigme Sangye Wangchuck back in 1976. It is protected under their forest act and it is totally forbidden to injure, kill, collect, or capture the bird under Schedule I of their forest act.
A pilot program was launched in Bhutan to breed the birds in captivity in the central district of Punakha. A chick was hatched this year which was successfully released. A meeting to foster international cooperation to protect the white-bellied herons has recommended the need for a breeding center in the country. One such center was funded by a hydropower project which gave 50 million ngultrums (around $672,000) for the project.
The society plans to set up a founder white-bellied heron population, with wild birds which will be used for breeding purposes. They will later be set free into the forests.