Bangladesh has introduced costly satellite transmitters for tracking migratory birds that will help identify their movements.
Nine birds were fitted with the transmitters, each weighing five grammes and costing Tk 3 lakh, on Friday and Saturday.
Tapan Kumar Dey, forest conservator (wildlife and nature conservation circle) of the Forest Directorate, told bdnews24.com that this was an unprecedented event.
Migratory birds come to Bangladesh every year as a stop on the 'Asian Flyway' and 'East Asian-Australian Flyway'.
"The task of identifying their migratory routes will be easier," Dey said, adding that previously ringing had been used.
"We will be also able to know whether there is any risk of bird flu infection through migratory birds," said Dey, chief.
Anwarul Islam, a Dhaka University professor and executive chairman of Wildlife Trust Bangladesh, said they had earmarked those species of birds which travel the longest distance routes, for example from the North Pole via Mongolia and Himalayas to Bangladesh.
"We will get information through signals on how high the birds fly, their routes and how many days they stay at each location on the way."
Dey said a transmitter is three percent of a bird's weight, the height is 1.5 inch, width 1 inch and the antenna is maximum 5 inch high.
The weight of the transmitters will not cause the bird's death, he said.
The transmitters were fastened to the birds in Moulavibazar district's Kulaura and Baralekha areas.
The US Geological Survey has supplied the transmitters. US Geological Survey, WTB New York and Food and Agricultural Organisation are funding the project.
Rings were also fitted on the legs of the birds. India-based Bombay Natural History Society is assisting with the ring project.
Anwarul Islam said migratory birds are usually blamed for carrying Avian influenza, which has been a major concern across Asia, Africa and Europe since 2003.
"We can now examine whether they really carry the virus," Islam said.
"Before fastening transmitters and rings we are examining whether the birds are carrying the bird flu virus. We are also examining their blood and stools."
Rings have been fitted on the legs of some 30 species.
Tapan Dey said they will use transmitters with 20 species of birds this year as the winter is over and the birds begin to leave the country.
At present, some 477 species of local and migratory birds are seen in Bangladesh; of them 301 are local and 176 migratory.