Bird watchers record more diversification, but no population increase at Pallikaranai in lockdown

“Back-to-back lockdowns had no major impact on birds frequenting the PML. But natural factors like seasonal rainfall, hydrology flow, water storage level in PML and adjacent water bodies and man-made activities like construction - urban development projects affected birdlife in the marshland located in the newly carved out Chengalpattu district,” said KVRK Thirunaranan, founder, The Nature Trust.

Bird watchers and volunteers of Nature Trust noticed that excess rainfall in February turned out to be a bane for the migratory water birds. For example, the long-distance migrant Little Stint bird population nose-dived due to excess water. The Nature Trust, monitoring these birds over the last decade, recorded 6,000 birds in last year’s census period, but this year, the numbers reduced to 2,000. Similar patterns were noticed among the Grey Head Lapwing and Wood Sand Piper population, Thirunaranan explained.

During the January 2019-20 census period, 41,849 birds were recorded and this year in January 2020-21, the numbers were 23,782. Similarly, results for March 2019-20 were 22,558 and in March 2020 -2021, the numbers were 18,789. However, in regard to diversification of species, Pallikaranai had more winged visitors with October, February and March breaching the 120-mark. “February saw the maximum of 124 species this year, 10 species higher than what was recorded in the previous year 2020,” Thirunaranan said.

Excessive rainfall, followed by six culvert works near Perumbakkam and road extension works near PML reduced sightings, explained bird watcher N Balaji. The excess water stagnation changed the bird migration pattern in terms of volume without affecting species diversification, Balaji added.