‘Radiation behind decline of house sparrows in city’, says Nandkishor Dudhe

There are more than 1300 species of birds in Indian subcontinent. Common birds like house sparrow are facing pressures in the form of developmental activities making it necessary to monitor them to understand their current status. Hence, Bombay Natural History Society (BNHS) conducted Common Bird Monitoring Program (CBMP) on Sunday at pan-India level to record the common bird species using the line transect method to ensure a scientific approach towards bird counting. Common Bird Monitoring Programme (CBMP) is a citizen science programme with the objective of involving maximum people in observing birds in their backyard. Nandkishor Dudhe, a research assistant who is leading CBMP, talks about the possible reasons for decline in number of house sparrows and the method used to monitor them.

MumbaiWhat are the reasons for decline in the number of house sparrows?

n In Mumbai, Rock Pigeon, Jungle Crow, Black Kite, Bulbul and House Sparrow are the common birds found here. Urbanisation is the main reason for the decline in the number of house sparrows today. The apartment-like buildings and glass buildings have put restrictions on sparrows for building their nest in urban areas. However, in villages, the soil-constructed walls allow the sparrows for building their nest in the area between the wall and roof. Sparrows are also known to build their nest in smaller holes found inside the walls of the well in rural areas. Hence, large numbers of sparrows today are found in rural areas and lesser in urban areas. Apart from urbanisation, sparrows are also largely affected due to radiations created by mobile towers. However, no studies have confirmed the same.

How does the line transact method help in monitoring the common birds?

In a line transact method, a pre-determined route of 2 square km area is fixed on a particular grid area using Geographical Information System (GIS) which captures all types of geographic data. The bird watchers and bird enthusiasts count the number of birds inside the grid area provided by BNHS based on the location of the bird watcher. We provided areas like city, village, forest area, grassland, agriculture land and water bodies to the bird watchers for getting a better perspective of number of common birds spotted in different environment.

Since sparrows are suffering due to lack of nesting spaces, how can one build their own artificial nests at home for the sparrows?

It is very important that the artificial nest is placed in an isolated area. The nests must be built at a height that cannot be reached easily by domestic pets which is likely to harm the sparrows. The nest can be built using plywood or carton box, which can attract the sparrows.

Was there any previous survey conducted on house sparrow by BNHS?

In 2012, an online survey was conducted between April 1 to June 15 to gather information about House Sparrow population across India and to understand how they have changed in recent times. Based on the report, it was found that there were twice as many reports of large flocks of sparrows in rural areas as compared to cities. Around 2259 sparrows were reported in villages and around 1743 sparrows were reported in urban areas. As far as cities are concerned, Greater Mumbai reported 977 number of sparrows, Coimbatore  – 378, Pune  – 470, Hyderabad  – 278, Delhi-NCR  – 837, Bangalore city  – -566, whereas Chennai city reported lowest number of sparrows at 238.

What is the next step after the monitoring program?

The monitoring program is conducted across three seasons, namely monsoon,  winter and summer season. The current program was conducted as a part of common bird monitoring during the rainy season. People from Gujarat, Madhya Pradesh, Jharkhand and Maharashtra have participated in large numbers in the CBMP conducted on Sunday. A final report of all three seasons would be compiled by BNHS to understand the present population of common birds across India.

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