66 bird species seen first time in Siang
Guwahati: Altogether 66 species of birds, including six globally threatened species, have been reported for the first time in the first comprehensive survey of birds in the Upper Siang region of Arunachal Pradesh.
The survey was the result of six years (2010-16) of data collected by Anirban Datta Roy of Ashoka Trust for Research in Ecology and Environment for his PhD field work. The results have been published in the current issue of the Journal of Threatened Taxa. The other two persons who collected data are Vivek Ramachandran and Karthik Teegalapalli. Together they recorded 252 species.
"This is the longest bird survey in the region and provides the most comprehensive list of avian species in Siang Valley. Sampling for the study took place across the seasons, unlike previous studies which were restricted to the dry, cold months. This temporal spread in sampling allowed us to record species which were present only during the warmer months such as cuckoos and migrant waterfowl which were never recorded earlier in this region," Datta Roy told The Telegraph.
"Altogether 66 species of birds were reported for the first time from this area. We recorded nine species of cuckoos and migrating waterfowl such as Greylag Goose Anser anser and Mallard Anas platyrhynchos, none of which had been recorded before from Siang Valley," he said.
The presence of migratory waterfowl indicates the importance of Siang Valley as a migratory route.
While the majority of identifications were done through field surveys based on sightings and calls, a few species were identified from dead specimens that were killed by local hunters.
Datta Roy said all these species were detected in areas outside the protected areas, within areas that are farmed and managed by the Adi tribe of Upper Siang. The practice of shifting cultivation gives rise to a diverse landscape which has fields, fallows and forests.
"Such a diverse landscape supports the diversity of the species that we found. If these areas are replaced with settled cultivation or monocultures such as plantations, it is unlikely that so many species would still be found," he said.
"There are larger threats to this region in the form of massive dams that are being planned. Our discovery of migratory waterfowl and the high species diversity in this region should serve as concrete reasons to oppose the destruction of this beautiful and biodiverse region" he said.
The valley attains a unique character as the Brahmaputra carves through the snow-laden mountain ranges to depths as low as 300m.