A bird expedition in the Sundarbans at the start of this year has recorded 168 species and 30,986 birds.
Among the species sighted, 57 are migratory, and 111 are resident, said an official of the Sundarban Tiger Reserve, which hosted the festival.
Forest minister Birbaha Hansda released the preliminary report of the festival on Tuesday.
Among the total number of species recorded, 14 are threatened.
The fourth edition of the Sundarbans Bird Festival was held from January 23 to 27.
From January 24 to 26, six teams of photographers set out on boats to trace the birds along different routes of the delta — islands interspersed in a maze of rivers and creeks.
Each of the six teams had a forest staff and a “resource person”. They covered the areas of National Park East and West, Basirhat, Sajnkehali Wildlife Sanctuary in the Sundarban Tiger Reserve, and the Matla and Kalas ranges within the South 24-Parganas forest division.
The mangrove delta is a vital pit stop for migratory birds. Two of the eight well-established migratory routes — flyways — on the planet overlap in the Sundarbans, said veteran birders and foresters.
The great knot, red knot, godwit, sanderling and common crane are some of the migratory birds that use the delta as a stop.
Most species (105) were recorded from the Basirhat range, followed by Kalas
(85) and Matla (76). Some of the species overlap different ranges.
The report listed 45 species of mudflat birds; 11 raptors; 99 forest birds, and seven kingfishers. The 14 threatened species recorded included the Eurasian curlew, grey plover, great knot, common redshank and white-rumped vulture, which was sighted for the first time during the bird festival.
Every year, hundreds of thousands of migratory birds embark on an intercontinental journey. Typically, the journey links northern breeding grounds in Arctic and temperate regions, where winter is extremely harsh, with warmer non-breeding (wintering) sites in temperate and tropical areas.
The previous edition of the festival had recorded 153 species, and 31,927 birds were sighted.