Where Do Birds Go?
Ringing studies by BNHS unravel the long-distance migration by birds.
In 2017, a medium-sized shorebird, the Terek Sandpiper was ‘tagged’ in Gujarat’s Gulf of Kachchh. This May, the bird was spotted in Jandola, Khyber, Pakistan. A Curlew Sandpiper tagged in March 2019 at Navi Mumbai has been spotted this year all the way in Tangu saltpans in Tianjin, China, near the shoreline. Bird banding and ringing activities by BNHS are revealing fascinating insights into migratory birds – the political boundaries they cross, and the potential hurdles they conquer on the way.
The Indian Skimmer is a striking black and white bird with a bright orange beak. The known breeding population is in India, making India’s conservation efforts crucial for the survival of this species. Tagging of the Indian Skimmer revealed the movement between India and Bangladesh, highlighting the need for international collaboration.
Bird ringing is a study that involves banding a bird with a lightweight metal ring, with a unique alpha-numeric code. In addition to the metal ring, BNHS also uses colour flags, colour bands and neck-collars on certain species. These colour combinations are in accordance with the international flyway protocols (each region has a different colour, to avoid redundancy in the combination). BNHS is a veteran at bird ringing, having done this for over 90 years. We use our wide citizen and ornithological network to track birds in other countries. Most tagged individuals are identified through high-resolution photographs.
With increased interest in birds among the general public coupled with some of the highly popular citizen science programs and wise use of social media, we expect to get more and more records of these tagged birds – says Dr. Bivash Pandav, Director of BNHS. BNHS also looks forward to the active involvement of its members in reporting more and more such tagged birds from different corners of India, adds Dr. Pandav.
India is the current President of the Convention on Migratory Species. India falls under the Central Asian Flyway (flyways refer to the paths bird follow in the sky, this flyway mainly has North to South winter migration). India has recently launched a National Action Plan for the Central Asian Flyway. It has a leadership role in protecting migratory birds and working with other countries along the flyway. A network of 29 sites comprising of 20 major wetlands and nine wetland clusters have been identified as critical sites for migratory waterbirds under the CAF National Action Plan and are being surveyed by BNHS. The Forest Department frontline staff of these sites are being trained in the basics of bird migration, monitoring and bird ringing for better implementation of the management activities.
A few birds tagged in India were resighted far away from its border in the migratory season of 2020-21 Map Source: Bird Ringing Database, BNHS
Each year, an estimated 50 billion birds undertake such migrations across the globe. Their route, timing and ecology of migration is always surrounded by intrigue. The bird ringing-recapture/resighting method is the robust way to study these birds.
BNHS, one of the oldest conservation organizations in India, initiated a bird ringing study in 1927 and since 1959 it has carried out systematic, large-scale ringing studies.
Sites such as Point Calimere, Keoladeo National Park (Rajasthan), Harike Lake (Punjab) Manjhaul & Kawar Tal (Bihar), Karera (Madhya Pradesh), Chhari Dhand, (Gujarat), , Pulicat Lake, Tirupati Hills, (Andhra Pradesh), Palni Hills and Mandapam-Rameswaram (Tamil Nadu), Parambikulam Wildlife Sanctuary (Kerala), and Chilika Lake in Odisha were the intensive bird ringing sites during 1980s and 1990s. Sites like Point Calimere (Tamil Nadu) and Chilika Lake (Odisha) continue to be monitored by BNHS for decades. In addition to the two long-term ringing sites along the East coast, currently in Mumbai intensive ringing and color flagging studies are being carried out for the last seven years. BNHS is also engaged in ringing activities in Manjeera (Telangana), Kannur (Kerala), Khijadiya (Gujarat), Chambal (Madhya Pradesh), Mahanadi (Odisha) and Ganga (Bihar).
In 2007, a Bird Migration Study Centre at Point Calimere was established to serve as the headquarters for the Society’s bird migration studies. The Centre has the distinction of imparting bird ringing training to researchers, Forest Department staff and amateur birdwatchers. In 2017 with the support of the Chilika Development Authority (CDA), another bird ringing Centre was established at Chilika by BNHS.
Based on these recoveries, the breeding zones, migratory routes, and stopover sites of more than 40 species were well documented. The information obtained through these intensive studies was pivotal in delineating the boundaries of Central Asian Flyway (CAF) and the overlap of East-Asian, Australasian (EAAF), and African Eurasian flyways with the CAF. For those birds recovered beyond the national boundary, BNHS has been the key point of communication and the ringing information has been communicated with the respective Bird Ringing Schemes. Active involvement from birdwatchers and photographers in recent times has revealed some interesting information on the movement and site use of these tagged birds.
Importance of wetlands in Mumbai for migratory waterbirds
BNHS scientist, Mr. Mrugank Prabhu and his team are studying migratory birds and their migration routes through bird ringing and color flagging in Mumbai since 2018 and have so far tagged ten thousand birds of 36 species. Resighting and recapture records of these marked birds provide better insights regarding migratory routes, site fidelity and turnover rates. This information would be useful for proposing species-specific conservation actions in the future.
Through the earlier studies, gulls, terns, shorebirds and flamingos ringed in Central Asia, Persian Gulf, eastern Asia and along the islands in the Indian Ocean were recorded along the coast of Maharashtra. Recently, one such bird marked by Mr. Mrugank and his team resighted in Tianjin province of China (shown in the map) is the first record of international resighting of a waterbird tagged on the coasts of Mumbai and adjoining wetlands. The bird Calidris ferruginea commonly called Curlew Sandpiper was first caught and tagged at wetland behind T.S. Chanakya in Palm beach road, Nerul on 18th March 2019 with a unique flag no. 7N5. Subsequently, the same bird was recaptured on 13 January 2020 at Bhandup Pumping Station, and then it was resighted at Tianjin in China on 6th May 2021 during its northward migration to the breeding site. Migratory birds wintering at Thane creek use the adjacent wetlands as their high-tide roosts. Remarkably these birds show high fidelity to their traditional feeding and roosting sites as it is evident from their frequent resightings at these wetlands in the same as well as subsequent migratory seasons. This signifies the importance of these habitats and the urgent need for their conservation.