The traditional architecture allowed sparrows to make their nests in a holes, roofs, crevices of old houses .But modern architecture which introduced box – styled flats have no provision for sparrows to nest and lay eggs.
Groceries to Supermarkets
Few years back, grains were sold in grocery stores . The grains spilt from gunny bags were a major source of feeding omnivorous birds like sparrows. The grains were dried in huge quantities out in the open, which gave the birds their share of the introduction of grains. But now the scenario different because of Food Bazar and packaged food.
The scientist who are trying to unravel the cause of Sparrow’s disappearance have identified a new culprit: the mobile phone. Studies have warned about the effects of these mobile radiations on reproduction and fertility of eggs. Animals navigate by the Earth's magnetic fields and these waves can disturb a bird's ability to find their way around.
Unleaded Petrol and Insectcides
The extensive use of pesticides and insecticides in our farms and gardens have created a scarcity of insects. The unleaded fuel, believed to be eco-friendly, has harmful byproducts. The fuel uses Methyl Tertiary Butyl Ether (MTBE) as an anti-knocking agent. By mixing with the byproducts of combustion, this kills small insects.
Though adult sparrows can survive without insects being a part of diet, they need these to feed their young ones, and hence, the infant mortality rate of sparrows has gone up.
Pigeons, Crow and other big Birds Population
Religious beliefs encourage feeding of a particular species of birds and therefore, the birds like crows and pigeons have outnumbered small birds. These birds dominantly occupy the feeding and nesting sites.