BETTIAH, Jan. 10 -- As the cold wave tightens its grip and temperatures continue to fall, districts across northern Bihar have emerged as major stopovers for a diverse array of migratory birds arriving from across the globe during this winter. According to forest officials, the dipping mercury and the region's favourable wetland ecosystem have begun drawing winged visitors from as far as Russia, China, Mongolia, and several European nations to Gopalganj, West Champaran, East Champaran, Muzaffarpur, and Sitamarhi districts. "Yes, several parts of Sitamarhi district-particularly the wetlands and stretches along the Bagmati - are witnessing an influx of migratory birds. Preparations are underway to count their numbers and identify the species," said Amita Raj, divisional forest officer (DFO), Sitamarhi. However, on a lazy winter morning at the Udaipur Wildlife Sanctuary (UWS), about 8 km from Bettiah in West Champaran, the forest wakes gently. A soft cooing breaks the silence as a lone dove calls from the canopy. Almost instantly, a pair responds, followed by several more until the chorus swells to a frenzied pitch before melting back into the calm of the jungle. Such early-morning symphonies, including cycling of birds over waterbodies, have now become a defining feature of this often-overlooked trail inside UWS. "Otherwise home to nearly 300 species, the wetlands and stretches along the Gandak river, Udaipur, and the Valmiki Tiger Reserve (VTR) have quietly evolved into thriving stopovers for a remarkable variety of bird species these days," said Dr Nesamani K, conservator and field director of VTR. Officials in Gopalganj, East Champaran, Muzaffarpur, and Sitamarhi also confirmed the steady movement of migratory species since early December last year. "The pre-survey for the Asian Waterbird Census (AWC) 2026 has already recorded the arrival of Northern Pintail, Gadwall, Red-crested Pochard, Ruddy Shelduck, and Ferruginous Duck, among other species. These birds travel thousands of kilometres from Europe, Russia, Africa, and several other regions via the Central Asian Flyway and the East Asian-Australasian Flyway. The main AWC count will begin shortly, covering larger areas," said Ahbar Alam, a biologist who was part of an agency involved in the pre-survey for the Asian Waterbird Census (AWC) along with forest personnel. These migratory birds are likely to stay in the region till March, he added. In West Champaran, surveys will include the Gandak river, Udaipur lake, Daruwabari wetland, and several other waterbodies, he added. Among the other migratory and local species spotted in West Champaran, Muzaffarpur, and East Champaran wetlands are the Black-capped Kingfisher (Halcyon pileata), Common Pochard (Aythya ferina), Ferruginous Duck (Aythya nyroca), Black Drongo (Dicrurus macrocercus), Brown-headed Barbet (Megalaima zeylanica), Crested Serpent Eagle (Spilornis cheela), Common Moorhen (Gallinula chloropus), Northern Pintail (Anas acuta), Pond Heron (Ardeola grayii), Black Francolin (Francolinus francolinus), Intermediate Egret, Ruddy Shelduck, Asian Openbill Stork, White Wagtail, and Barn Swallow, among others, said forest officials. When contacted, Gopalganj's divisional forest officer (DFO) Megha Yadav said the sighting of the Ferruginous Duck-an endangered migratory species from Mongolia - and the River Lapwing, a near-threatened bird listed under the IUCN status, was "quite heartening." "To ensure the safety and conservation of these birds, the Forest and Wetland Conservation Department has been continuously taking necessary actions," said DFO Yadav. Forest officials said that by virtue of Bihar lying at the foothills of the Himalayas, it is naturally endowed with rich biodiversity. "If we talk about migratory birds, India falls under the Central Asian Flyway (CAF), through which these migratory birds travel. This route extends between the Arctic region and the Indian subcontinent, covering 30 countries. Every year, as part of this flyway, a large number of rare and endangered birds are spotted in the Gopalganj forest division. Under the Gopalganj division, three wetlands (Tirkuhiya River, Sitaula Pond, and Mahuatand Sarovar) are included," said Gopalganj DFO....