March 17, 2025
DHAKA – Winter has passed, and spring is in full bloom at Jahangirnagar University. However, the real surprise isn’t the blooming flowers, but the return of hundreds of Lesser Whistling Ducks to the lake. After six years of early departures, with empty waters by late February, these migratory birds have finally made a comeback.
Traditionally, Lesser Whistling Ducks migrate to the “Transport Lake”, located next to the transport yard in JU, from both abroad and various regions of the country, staying throughout the winter. However, in recent years, their numbers have been declining. Over the past six winters, many left earlier than usual, often by mid-February. This winter, an even more alarming trend emerged — while these migratory birds were first spotted at the lake next to the Al-Beruni Extension Hall on November 9, 2024, many disappeared as early as December. Transport Lake, once a thriving habitat, was nearly devoid of them.
“Waste accumulation and the disappearance of duckweed, a crucial food source for the birds, are the two major reasons for their decline. Without duckweed, the lake lost its ability to sustain these migratory species,” said Professor Jamal Uddin, chairman of JU’s environmental science department.
To address this issue, Auritro Sattar, an Environmental Science major at JU, initiated an ecological restoration project in early February under Prof Jamal’s guidance, with support from the JU administration. He collected duckweed from various locations and reintroduced it into Transport Lake.
“Duckweed grows rapidly, and within weeks, the lake became a rich feeding ground again. In addition to being a vital food source, duckweed acts as a natural filter, absorbing pollutants such as ammonium, nitrate, and phosphorus, which contribute to water pollution and eutrophication. Once these pollutants were reduced, the lake became more habitable for migratory birds,” Auritro explained.
The intervention yielded remarkable results. Within a month, on March 6, researchers using the point counting method observed around 280 Lesser Whistling Ducks at Transport Lake — their first recorded visit this season after previously abandoning the site. Over the following days, their numbers grew to nearly 350. The birds gathered in areas rich with duckweed and water lilies, while some rested on bamboo platforms installed to attract them. This conservation success underscores the potential of ecological interventions in restoring JU’s lakes as thriving habitats for migratory birds. Auritro emphasised that continued restoration and pollution control efforts are essential to ensuring these lakes remain safe stopovers for migratory species in the future.