Starting early November until yesterday, a total of 422 black-necked cranes (grus nigricollis) have arrived at their winter grounds in Bhutan.
At 340, Phobjikha has recorded the highest number cranes, the black-necked crane visitor centre’s manager, Santa Lal Gajmer said.
In Bumdeling, 60 cranes have arrived. “More cranes are expected because last year it kept flying in until December end,” Bumdeling wildlife sanctuary forester, Tshering Chophel said.
This time Khotokha has received 14 cranes, six more than what it received last year. “There are 10 in Khotokha and four are roosting about five kilometres further down in Shelay,” Rubesa gup, Gyeltshen said.
Although more are expected, only five cranes have arrived in Gyetsa against the 22 that flew in last year.
Three black-necked cranes have also landed in Dungkar, Lhuentse. “A juvenile and two adults reached here on November 30,” Wangchuck Centennial National Park forester, Karma Yeshi said.
However, Tang and Chokhortoe in Bumthang, which are also the bird’s winter grounds are yet to see any cranes.
“We haven’t heard the cranes calls, which normally would be the first indication of their arrival,” Khangrab tshogpa, Tshering Dorji said.
Tangmachu also hasn’t reported any cranes.
Ugyen Wangchuck Institute for Conservation and Environment (UWICE) ornithologist, Sherub said the cranes’ arrival every winter is a healthy indication. “It means our country is still a safe haven for the cranes,” Sherub said.
He is however, sceptical about more cranes arriving in Chumey.
“Most cranes migrating for wintering grounds must have already arrived since the peak migration is nearing an end,” Sherub said, adding other factors such as weather conditions and carrying capacity of the roosting and feeding grounds are also likely to have influenced the number of cranes.
Last year, UWICE confirmed internal migration in winters within Bhutan through its research on trans-boundary migration.
“One of the four cranes named Ugyenling, which researchers tagged with GPS in 2011 landed in Gyetsa last year and after few days flew to Phobjikha,” UWICE director, Nawang Norbu said.
Four cranes – Ugyenling, Samtengling, Losarling and Rinchenling respectively were tagged with GPS. The GPS since has been sending the researchers an email every evening on their location.
“Through these email messages, we know exactly where they are every day,” Nawang Norbu said.
By compiling data from these emails, the researchers also confirmed the cranes of following multiple trans-boundary migration routes. It was found that for their next migration flight, the cranes do not necessarily follow the same migration route it used while flying to Bhutan and returning to Tibet.
According to the GPS readings, Ugyenling came to Phobjikha from Bamtsho in Tibet through Jomolhari pathway in 2013 and returned to Bamtsho the same way.
While in Tibet that summer, Ugyenling flew further north to Yamzho-Yumco in Lhasa Prefecture and the following winter, it flew directly to Gyetsa via Lunana Mangdechu pathway instead of flying back to Bamtsho to return to Bhutan from Jomolhari pathway.
The same crane had also flown back directly to Yamzho-Yumco from Phojikha in 2012 against the traditional thought of it returning only via Bamtsho.
According to UWICE, trans-boundary migration research would go a long way in determining what weather conditions and environmental factors influence the cranes’ migration. The research would also enable plan conservation in regional scale with information on its stopovers between Tibet and Bhutan.
“If we manage to secure these critical areas, obviously the species are safer,” Nawang Norbu said.
Meanwhile, it is still unknown from where in Tibet the cranes to Lhuentse and Bumdeling come from. “We would know only if we tag one of these cranes from there,” Sherub said.
Last year, 544 cranes flew to Bhutan.
Tempa Wangdi, Bumthang