"Birds like the bar-headed goose, red-crested pochard and greylag goose are arriving in small numbers. Poaching is certainly one of the major reasons as villagers often kill them for feasts or livelihood. Moreover, these birds become prey to flu," said MS Dwivedi, a member of Indian Bird Conservation Network (IBCN) cum Ph D research scholar at the department of zoology, VinobaBhave University (VBU).

MohdRaziuddin, former pro-vice chancellor of Ranchi University and professor in department of zoology at VBU, said, "Factors like poaching are possibly resulting in the fall in number of migratory birds." However, the wildlife department is unsure about the decrease in population of these birds and will soon launch a survey. "It is difficult to maintain a proper count of the migratory birds visiting the state during winter. They come in small groups and are scattered. We will start a survey engaging NGO members, wildlife officials and resource persons within a week to resolve the issue," said Lal Ratnakar Singh, principal conservator of forests. The migratory birds arrive in November and return by March every year.