The Disappearing Sparrows

I have been staying in Bangalore ever since my childhood. The city has been my home. I have seen Bangalore transform into a megapolis from a small time town. During the course of this transformation, what I have noticed is that there are no more sparrows in Bangalore. They used to be in such abundance when I was a kid. My mom used to throw some rice in our balcony and these cute birds would come by chirping to peck on the rice. They built nests in our compound and it was so thrilling to see those young sparrows emerge from the nests. But now, 15 years later all these birds are gone. I was chatting with one of my friends in this regard. He is a bio-tech guy and has incidentally done some research into this aspect. According to him, the reason for the disappearance of sparrows is the carbon monoxide pollution. It might sound obvious, but how the pollution is linked to the sparrows is interesting. The young sparrows are fed with a particular breed of 'bug' that is rich in protein. For the first three days after birth, these bugs are the life of the young ones. Apparently, vehicular pollution has killed these bugs and that has led to the death of several young sparrows. As a result, their population has diminished or they have migrated to other safe havens. The same phenomenon has been observed in all major cities of the world, and London is the foremost example. May be it was all meant to happen like this, but I certainly miss those cute birds.