Sampath Kumar | Mar 3, 2020, 04:37 IST
Trichy: There has been a decline in the number of migratory birds arriving in the delta region this year even though their diversity has remained largely unaffected. This was revealed in the synchronised annual bird census carried out at three sanctuaries in Tiruvarur district and Point Calimere in Nagapattinnam on Friday. The forest department had roped in Biodiversity Conservation Foundation (BCF) Trichy and ornithologists with an objective to assess the diversity of migratory pattern of aquatic and terrestrial birds in the region. Saying that birds are an indicator of an ecosystem, BCF founder-director A Kumaraguru said birds take a lot of effort and face challenges to reach a place. They ensure that the place they migrate to is rich in nutrients and ecosystem values.
“Drop in the number of birds could be the fallout of the devastating cyclone Gaja that hit the delta region in November 2018,” said Kumaraguru. But it was interesting to note that there was not much decline in terms of the bird species which remained between 115 and 134 in these places, he said. Confirming the decline in the number of birds arriving in the sanctuaries in the delta region, S Ramasubramanian, conservator of forests, Thanjavur circle, said, “About 15,000 birds were recorded in Uthayamarthandapuram bird sanctuary which is 5,000 birds less than last year. Similarly, there is a decline of about 5,000 in Muthupettai lagoon.” Flamingo population has been largely affected in Point Calimere. They appear to be migrating to Rameswaram because of Gaja cyclone last year which has affected the ecosystem in this region.
A Aroon Saayee, student of Vellore Institute of Technology (VIT) University, was part of last year’s census. Being part of the team carrying out boat survey as part of the census this time, he had a close encounter with birds. Aroon said there could be two reasons for the changing migration pattern.
“There could either be a delay in the migration of birds to this place or they have migrated to some other place,” he said. “It will take at least a year more for the feeding area to recuperate in these regions. Mangrove areas are being desilted so that micro-organism could feed in large numbers which are the primary feed for these birds,” said Ramasubramanian. “We have comprehensive data of the arrival of birds in the last four years. This will help us study the factors hindering their habitat,” he added.