Kolkata: The annual census at Santragachi Jheel conducted last weekend recorded the least number of migratory birds in five years, triggering concerns among naturalists.
While the count has been declining over the last few years, the slide in the past three years has been dramatic: from 6,742 birds in Jan 2022 to 4,197 this Jan.
According to Soumya Ray, the secretary of Prakriti Samsad, which has been conducting a census at Santragachi Jheel every Jan for the past decade, while the number of lesser whistling duck has not changed significantly, no trans-Himalayan birds were recorded this year. The census was conducted on Saturday.
While 15 species of birds had been recorded at the jheel in the past, only seven were spotted this year. The largest species found during the census was the lesser whistling duck, whose number was pegged at 4,152. The next highest was 13 cattle egrets, followed by nine common moorhen, six each of bronze-winged jacana and barn swallow, and one kingfisher and intermediate egret each.
"Usually, we used to find a few trans-Himalayan migrants like pintail, gadwall, and common teal at Santragachi Jheel. But none of them was sighted during the exercise this year," said Ray.
In Dec, TOI reported how the inordinate delay in clearing hyacinth from the jheel by nearly two months could disrupt the arrival of migratory birds and lead to a poor bird count.
Leena Chatterjee of Nature Mates, who has been clearing hyacinth from the jheel, acknowledged that the clearing delay could have affected the early arrivals. But she said the most overlooked factor is the ecological degradation of the feeding ground of these ducks due to a drastic change in the land use-land cover pattern of the surrounding areas.
"These ducks use Santragachi as their day roosting area. They mostly forage during the night at the nearby agricultural field. The adjacent areas of Santragachi Jheel are facing a drastic change, from agricultural practices to domestic or industrial use. This transformation is having a significant impact on this decline in the numbers as well as in the diversity," she said.