Urbanization and toxins like nitrogen in lakes is driving pied kingfishers out of Bengaluru.
The pied kingfisher is scarce to come by in the city for the past few years. Bird watchers said that this was a result of habitat destruction and loss of biodiversity.
Dr. Krishna MB, ecologist and ornithologist said that there has been a tremendous change in bird life and their habitat due to technology over the past quarter century. “Bengaluru city exploded after information technology (IT) boom and it resulted in loss of species leading to their extinction,” he said.
Naren Sreenivasan, conservationist at Wildlife Association of South India explained the impact of extinction of species on the environment. Naren said, “the impact of extinction of any species results in the imbalance of food chain and damage to the other population of animals and plants as well.” He added that the decline in pied kingfisher numbers has resulted in an increase in small fishes and insects in lakes as these birds controlled the small fish population.
Pied kingfisher, prey mainly on tilapia fish, African cat fish and other native fishes, said Naren. “During 1987-1996, ecologists sampled water and surveyed lakes,” said Dr. Krishna, the results showed toxins like phosphorous and nitrogen in samples, which is consumed by fishes and in return by birds who prey on them, he added.
Pied kingfishers are ground-nesting birds and prefer to stay near the edges of lake, they dig out their nests on settled mud near the lakes and rivers. Srinivasa, an animal attendant from People for Animals (PFA), said, “Pied kingfishers are declining because they are not able to build their nest on sides of lakes due to an increase in construction around it.”
Dr. Krishna explained that not only nitrogenous waste but the amount of salt in sewage also results in killing of fish and indirectly birds, as salt is soluble in water and fishes living in this habitat are not salt water fishes. “Increase in number of people means increase in sewage which flows into the water bodies, killing sea life and birds that prey on them,” he said.
Bengaluru now has more still water bodies and fewer flowing water bodies; this results in the death of pied kingfishers as they can’t see the ground while preying the fishes. Dr. Krishna said, “pied kingfishers hovers in air and dives down for fish, but scattered vegetation, thick and murky water makes it difficult for birds to spot the fish.”
The Bruhat Bengaluru Mahanagara Palike (BBMP) is now surveying birds and animals which are on verge of extinction and maintaining a register for biodiversity inventory.
According to State of India’s Birds report, 2023, around 60 percent of birds in India have experienced population decline over the long term of 30 years.
