Birds take flight from a concrete Bengaluru

Bengaluru: The number of bird species has fallen sharply in the last three decades in Bengaluru, according to bird watchers and ornithologists who blame the city’s vanishing lung spaces and lakes for the misfortune.

Data from eBird, an online database of bird observations, shows that 133 different species of birds were spotted in Hebbal Lake between 2015 and 2020; this figure slid to 119 between 2020 and 2024.

Kaikondrahalli Kere, located in southeastern Bengaluru, which housed 112 bird species in 2016, had only 86 of them last year, indicating a sharp decline in bird movements in less than a decade. 

Bengaluru recorded around 340 species in the 1980s. But bird watchers and ornithologists say the number has fallen to double digits at many lakes, in a reflection of the grim situation. 

When the authorities rejuvenate lakes they make them into soup bowls with a lot of water. Halasuru Lake and Sankey Tank are classic soup bowls with very little biodiversity.

Garima Bhatia (birdwatcher)

Painted Stork

The city now has herons, egrets, ibises and storks, long-distance migratory birds such as sandpipers and stinks, reed birds like bitterns, water hens and moorhens that depend on the shoreline vegetation. 

Ornithologists say that besides declining lung spaces, unscientific rejuvenation of lakes and concretisation have been taking a toll on the birds that thrive on fish, insects, nuts and fruits. 

Lake conservationists argue that lakes managed by the Bruhat Bengaluru Mahanagara Palike (BBMP) conform to urban elitist notions that the spaces should accommodate joggers and walker communities, even as the wildlife’s rhythm is disrupted by the encroachment of their natural habitat. 

Garima Bhatia, an ardent birdwatcher, said the biggest factor for the declining bird species was the lack of knowledge and awareness on lake ecosystems among authorities. 

"When the authorities rejuvenate lakes, they make them into soup bowls with a lot of water. Halasuru Lake and Sankey Tank are classic soup bowls with very little biodiversity," she said, adding several water birds depend on shallow water and marshy areas for food. 

Moreover, untreated sewage water comes into the lake, further damaging the lake ecosystem. Kaikondrahalli Lake's fate is a classic example.

The lake used to be a model lake for public-private partnerships, with resident welfare associations and the BBMP working together. Now, the lake has become just a sewage dump. The main reason for this, she thinks, is apathy of authorities. 

M B Krishna, ecologist and ornithologist, told DH: “During the late 1970s and the early 1980s, we used to see nearly 20,000 migratory ducks in Bellandur Lake and over 800 in Lalbagh Lake. We no longer see them." 

Spelling out the reasons for the alarming decline in bird species, he said, "In most of the urban lakes managed by the government, the shorelines have gone, the lakes have deepened like soup bowls, the reedbeds have been dug up and lined with concrete, with hardly any vegetation to protect the bird species." 

Shallow zones of a lake with rich vegetation are a prerequisite for wading birds to thrive, he added. 

V Ramprasad, co-founder of Friends of Lakes, and lake conservationist Raghavendra B Pachhapur said with the false idea of beauty which the officials in government have, "monoculture has taken over the place of indigenous plants". 

A senior official with the BBMP said efforts to rejuvenate and replenish at least 10 lakes in the city were underway. "Efforts are on to remove encroachments and further the ecological development around at least 10 lakes. Removing the encroachment around the lakes will take time but we are at it," said the official.