A Survey on House Sparrow Population Decline at Bandel, West Bengal, India

Abstract

The population of House sparrow (Passer domesticus), once a very common bird, has declined markedly in most parts of the world including India. Sparrows were distributed widely in the district Hoogly, West Bengal, India. However over the past few decades, they became not so common in this part of the world. A study has been conducted to establish the database for their current population and to assess the possible causes of their decline at Bandel (22 o 52'22''N/88 o 22'53''E) placed beside the river Hoogly from September 2008 to May 2009. After prolonged searching, a relatively dense population of sparrow (total subject 270) was found in busy areas of railway station and a nearby market in Bandel. The behavior of these birds was studied extensively from early morning to late night. The noise level of the area varied from 35 to 95 dB with an average of 70.6 dB from 04:30 am-10:30 pm, IST. It was also observed that the sparrows took rest on the site of the tree where the illumination level was low (30-45 lux). Sparrows residing at the Bandel station are habituated with the loud noise, being undisturbed by passing trains. Thus, it can be concluded that in spite of heavy noise of trains, crowdy travelers, and lack of nest sites, they remain at the station because of availability of food in the nearby roadside market. Based on this observation, sound pollution and availability of food are not responsible for their decline.