Unlike humans, birds can’t tolerate pollution. A few of them may adapt to certain degrees, but not to extremes.
Thanks to pollution, the house sparrow, which was once abundant in Chennai, has now become rare.
Except for the ubiquitous crow, majority of the indigenous birds have become rare or endangered in Chennai owing to unchecked urbanisation and depleting green cover, admit environmentalists and bird watchers in the city who will be observing the World Sparrow Day on March 20.
“Chennai was once home to sparrows, but today their population has reduced drastically and the same is the case with several other species.
We often blame cell phone towers and radiations as the reason for the disappearance of sparrows, but the problem is that we do not have a concrete study or conclusive report to prove that radiation affects bird life”, said Mr Sudhakar, president, Madras Naturalists Society.
MNS has been observing resident and migratory birds and plans to release a map indicating the sparrow habitats in Chennai, he added.
Professor D. Narasimhan, department of Botany, Madras Christian College, said, “The house sparrow is strongly associated with human habitations, and can live in urban or rural settings, but the city’s housing pattern has become unfriendly for nesting sparrows”.
Also, sparrows are low flying birds and cannot build nests in high-rises and flats, explained the botanist. Once sparrows used to nest above switch boards or in electrical fittings, but today even wirings are sealed leaving the tiny birds without space for nesting, he added.
The house sparrow feeds mostly on seeds of grains and weeds, and insects; it can perform complex and unusual tasks to obtain food. Details into its food availability can also help trace the reason behind their disappearance, said Mr Sudhakar.