Guwahati: In 1911–12, a team of British explorers, surveyors, and military personnel collected numerous zoological specimens, including birds, from southern parts of the Siang Valley in present-day Arunachal Pradesh, the findings from which were published as the ‘Zoological Results of the Abor Expedition 1911–12.
Over a century later, researchers from Ashoka Trust for Ecology and Environment (ATREE), Felis Creations, National Centre for Biological Sciences (NCBS), Titli Trust, and the Indian Institute for Human Settlements (IIHS) covered the same route with additional areas and meticulously recorded information on all birds directly sighted, or heard, or photographed on camera traps between February to May 2022.
The National Geographic Society, Felis Creations and the Arunachal Pradesh Forest Department supported the Siang Biodiversity Expedition.
Findings from the survey were published in the journal Indian Birds, which shed new light on the avian treasures of the Siang Valley. All direct sightings and sound recordings of the birds obtained were uploaded to the open-source citizen science application called eBird so that the data was freely available for scrutiny for anyone interested at any given point in time.
The efforts culminated in documenting a remarkable 285 bird species, call recordings of 94 species of birds and 26 species recorded as dead. From this short survey, 20 new records for the Upper Siang district, and 32 new records for the Siang district, along with one new hybrid species, Dusky x Naumann’s Thrush were also recorded for the region.
Some noteworthy sightings include the elusive Temminck’s Tragopan, Blyth’s Tragopan, and the Sclater’s Monal. The publication also provides important evidence for the Siang flyway which several species of migratory birds use to travel back to the northern latitudes at the end of winter. Based on the large flocks of common cranes, Amur falcon, Brahminy ducks, bar-headed geese, and the Eurasian hobby reported, there is sufficient evidence to identify the Siang valley as an important migratory route for birds.
The researchers sighted over 31 Amur falcons in the Upper Siang district suggesting this could be an important valley for these fascinating long-distance migratory birds.
In addition to the above, eight species of cuckoos, Asian Emerald Cuckoo, Plaintive Cuckoo, Square-tailed Drongo Cuckoo, Large Hawk-Cuckoo, Lesser Cuckoo, Indian Cuckoo, Himalayan Cuckoo and Common Cuckoo, all previously unreported from Siang district were sighted. For the Upper Siang district, the Banded-bay Cuckoo was a new record. The rare Oriental Bay Owl and a Rufous-necked Hornbill were sighted in the Siang district, making for interesting records reflecting the unique and incredible bird diversity in parts of the valley, despite its large human population.
The Dusky x Naumann’s Thrush, previously only reported from three districts of Arunachal Pradesh with seven records, was a highlight of the birds seen.
“While 12 species recorded during the Abor Expedition were not reported in this study, as per the researchers involved, most of these species have been seen in the region, albeit outside of the survey period, and hence not reported in the publication,” the researchers said.
The survey highlighted important conservation issues by documenting dead specimen records, particularly for mountain pheasants and brightly coloured woodland passerines. Major conservation issues currently faced in the region include hunting for food, local trade and trafficking; habitat loss and degradation due to multiple factors, such as the expansion of various forms of agriculture, such as shifting cultivation (jhum), wet cultivation, monoculture plantations, logging and felling for multiple purposes, including local-level use, timber trade, and the construction of mega dams.
A unique approach in this study was making the data collected on bird sightings and calls available on eBird for other researchers and bird enthusiasts to validate and use.
“The areas surveyed were also mostly outside of protected area network in human-use landscapes, suggesting that like most other parts of northeast India and Arunachal Pradesh in particular, the Siang Valley holds great potential as a high bird diversity landscape,” a researcher associated with the study said.
Also Read: Meghalaya board to introduce two SSLC exams starting 2024-2025