The number of Black-necked Cranes (Grus nigricollis) visiting the country has been increasing from 370 cranes in 1987 to 599 cranes in 2021.
However, the cranes visiting Bumdeling in Trashiyangtse are decreasing. The crane population decreased from 200 cranes in 1987 to 70 in 2021.
The Black-necked Cranes (BNC), considered sacred birds that bring blessings, are listed as near-threatened according to the IUCN’s Redlist of Threatened Species.
The Royal Society for Protection of Nature (RSPN)’s national coordinator for BNC conservation, Jigme Tshering, said that some possible factors for the declining wintering crane population in Bumdeling could be attributed to the shrinkage of foraging habitats.
“The cranes forage on paddy fields but shortage of labour and wildlife crop depredation has caused the farmers to leave the land barren,” he said.
The flash floods in 1994 that washed away agricultural land, reducing the feeding grounds of cranes, is considered another reason for the declining crane population.
BNC roost in marshes, bog meadows, or along riverbanks making their habitat susceptible to loss and degradation of habitat.
Jigme Tshering said that RSPN has been working with the farmers to protect the habitat of the bird.
To reduce wildlife crop depredation and encourage farmers, RSNP supported the construction of electric fencing benefiting 500 households.
He added that since 2018, with support from International Crane Foundation, RSPN has been trying to revive and enhance foraging and roosting sites in Bumdeling.
As a pilot project, RSPN restored 20 acres of paddy fields.
RSPN, Ugyen Wangchuck Institute for Conservation and Environment Research, and Bumdeling Wildlife Sanctuary have been tagging cranes in Bumdeling to identify migration corridors; winter, summer, breeding, and stopover sites; and habitat preference.
So far, six cranes each from Phobjikha and Bumdeling have been tagged.
Jigme Tshering said: “The sample size is small to draw any conclusion yet. We are working on finding more samples.”
But the studies until now show that cranes from Phobjikha and Bumdeling have different summer sites which could also be contributing to the declining number of cranes visiting Bumdeling, he said.
International experts point out that the bird species is threatened by droughts and desertification of wetlands related to climate change, as the melting of glaciers and the degradation of permafrost are expected to lead to water shortages and extensive loss of shallow wetlands in the long-term.
The current global BNC population has increased from around 7,000 to 11,000 birds since 1990.
“Some experts point out that the global increase in BNC population today could be because of global warming melting the glaciers and permafrost. Gradual melting of the cryospheric systems could pose a threat to BNC’s conservation,” Jigme Tshering said.
Jigme Tshering said that work is underway to recognise BNC as a flagship bird on the Central Asian Flyway. This, he said, will help to promote the conservation of the bird and their habitats.