SUBJECT :Biodiversity 
Loss of nesting sites and absence of food, particularly insects, are leading to fast reduction in the number of house sparrows (passer domesticus), most commonly spotted bird, in cities and urban areas. In last few years, the bird has gone completely missing from most urban neighbourhoods, however, they can still be spotted in rural areas.

"You won't find sparrows in jungles, deserts or places where there is no human habitation. The sparrow is a species that is always found in and around human habitations and as it prefers to nest in manmade structures such as cavities in walls, around streetlight poles, pipes emerging out of buildings and so on," said ornithologist Ajay Gadikar. However, architecturally modern buildings have no space for birds which is forcing them to move away from cities.

Nowadays, houses and buildings in cities are built with minimum outer projections and everything is concealed inside walls. Furthermore, modern buildings also have fewer holes and crevices.

Moreover, a dearth of food is driving sparrows away from cities. Insects are no longer found in towns due to rampant use of chemicals to kill pests. "Sparrows need to find plenty of aphids and caterpillars to feed their young ones, especially in first few days after hatching," said Gadikar.

He said the only possible way to keep sparrows in cities is to put nest boxes (bird houses) outside houses and bird feeders with grains to feed them. He said a nest box with circular hole, of around 10 cm diameter, should be kept at a height of 2 metres above the ground to shield it from cats.

Source: 20 March, 2015, The Economics Times