KATHMANDU: Nepal is truly a birds' paradise as it boasts of having a total of 864 birds species. And now, with the peak season of winter migration, more than 150 birds species have already made it to the country from various parts of the world this winter.

"Of the total birds species found in Nepal, about 600 are residential and the remaining are the migratory birds which visit Nepal flying long distances in winter and summer," said Dr Hem Sagar Baral, an ornithologist.

The migratory birds mainly come from the Tibet, Mongolia, Siberia and Eastern Europe and spend almost six months here. According to Baral, the winter migratory birds begin entering Nepal from mid-August and stay up to April.

The birds migrate to Nepal in search of favourable temperature so as to prevent themselves from the severe wintry cold.

Many ducks species such as Ruddyshel, Mallard, Gadwall, Common Teal, Northern Pintail, Woodsand Piper, Green Shank; song birds like Wagtails, Thrushes, Fly Catcher, Leaf Wabblers; and birds of prey like Long-necked Buzzards, Booted Eagle, among others, have already entered the nation, according to ornithologists.

"Larger Aquila eagles are expected to enter Nepal at the end of this month," added Baral.

However, the winter migratory birds do not breed in Nepal unlike the summer migratory birds. Many varieties of Eurasian Cuckoo are among the summer migratory birds which breed during their stay here, Baral said.

"The migratory birds have specific routes and mostly they fly via the Kaligandaki River course in west and Arun Valley in the east," said Baral, adding that the birds mainly migrate from Alpine and temperate to tropical and subtropical zones.

"As the days in the winter in the northern latitudes are short and the birds have less time to search their food, they come here. Some of the migratory birds fly up to southeast Asia through Nepal," Baral explained.

However, the country is yet to adopt the latest migration monitoring techniques like satellite monitoring to check the migration trend. "We rely on the 'eyewitness method' and ringing techniques on the legs of the bird which will make easier to confirm the arrival of the birds every year," Baral concluded.