Winged visitors revisit Mumbai

Mumbai: Birds are known to accentuate the health of their surroundings and hence bird studies have always assumed great importance. The resighting of ringed / colour tagged birds in the wetlands of Mumbai has spread a wave of enthusiasm and happiness among ornithologists. Curlew Sandpipers and Plovers were a few of them which were spotted recently. The resighting of these birds reinforces the importance of ringing studies being undertaken over the years. Moreover, bird ringing studies help to understand the paths used by birds over long journeys of migration, their stop-overs and preferences.

Significance of the resighting:
· Resighting of ringed birds highlights the site fidelity of these birds, that is, they choose to spend the winters in same wetlands year after year. Thus current resighting of birds from Mumbai after spending summers in their breeding grounds in Arctic Russia assumes significance of these mudflats as important wintering and staging site for long distance migratory birds.
· The Curlew Sandpipers ringed/colour tagged in the wetlands of Mumbai between December 2014 and February 2015 were spotted by Dr Raju Kasambe, a bird expert with BNHS (at Sewri) and birders S. Krishnan and Mr Ashwin Mohan (at Navi Mumbai).

Importance of mudflats:
Mudflats offer a valuable food source derived from their high productivity and the resultant high quantity of prey items for fish and waterbirds. This makes mudflats significant as feeding and roosting grounds for local as well as migratory birds. Mudflats also play a crucial role for habitat specialist waterbirds which travel over long distances by helping them gain the body mass required to complete their migratory movements. Mudflats are usually inaccessible and less disturbed which enhances their importance as resting, roosting and feeding sites for birds. The mudflats in Mumbai host a large congregation of waterbirds every year which includes both local as well as migrant birds.

Bird Ringing:
BNHS has been engaged in bird ringing studies since 1927 with over a million birds being ringed in various parts of the country. All of these studies were undertaken with continuous support and cooperation from the State Forest Departments. Owing to the vast experience in bird ringing and training volunteers for these studies, BNHS was recently designated as the State Nodal Agency for bird ringing studies by the Maharashtra Forest Department, and Mangrove and Marine Biodiversity Conservation Foundation has recently provided grant to map the important coastal wetlands in the context of Central Asian Flyway (CAF). From September 2017, BNHS will start large scale bird ringing along coastal areas of Maharashtra.

Understanding Flyways:
The specific paths used by birds during migration are known as ‘flyways’. The study of flyways forms an important part of ornithology as it helps to understand the challenges birds face during migration. Identification of movement routes and stopover sites of birds is important to develop appropriate strategies for conservation of migratory birds. BNHS has engaged in bird migration studies and collected data over the past 70 years to draw in-depth knowledge about the migration of birds. BNHS is set to map Central Asian Flyway with large scale ringing of birds along the coast of Maharashtra in order to study the current status of globally threatened and rare bird species (if any) to Indian wintering grounds. It would also help to study the movement and dispersal pattern of short and long distance migrants and to document the existence of important staging / wintering areas along Indian coast. We have received necessary permissions from the states of Gujarat, Maharashtra, Tamil Nadu, Puddichery, Andhra Pradesh, Orissa and Himachal Pradesh. We are expecting permissions from other states soon.

Dr Deepak Apte, Director, BNHS notes “The sighting of these ringed / colour tagged birds assumes great significance as it states that they are not casual visitors to the wetlands in Mumbai. We urge members and the birding community to get back to us with information about any sightings of ringed / colour tagged birds. This will be helpful in filling the information gaps in habitat preference and movement of long distance migratory birds.”