Where have all the sparrows gone?

Sparrows were an important part of my childhood. Every morning, after I had taken a bath and put on my school clothes, I would stand in the balcony eating a banana or an omelette with bread. I would often see groups of sparrows (twenty to thirty atleast) sitting on the ashoka trees in front of my house. Any slight disturbance - a car or a neighbour's cat - would cause them to immediately fly off and settle somewhere else. My mornings, needless to say, were not complete without a fly - by of a group of sparrows.
Over time, as my interest in going to school waned, so did the numbers of the sparrows. I did not notice their declining numbers though - I had other things on my mind. But I woke up one morning to find them gone. Now I'm not an avid bird watcher or enthusiast, but losing your daily morning dose of "chirp chirp" and suddenly realising that the little ones aren't around did make me sad. Over the next few years - both during college and travel - any sighting of the sparrow would delight me, something which would have been commonplace a few years back. A few months back, while travelling from Bangalore to Mumbai, a sight greeted me - a pack of sparrows feeding on leftover idlis. Needless to say, I took a highly zoomed (and terrible) photograph - it was, after all, a long awaited party (+1 to you if you get the LOTR reference)

                                     
I can only hypothesize the reasons for their sudden decline. A lot of people claim "loss of vegetation" to be one of the reasons, but it fails to explain the decrease in sparrows in a city like Delhi with its abundant green cover. I personally feel that the increase in EM radiations from mobile phone towers is a culprit. This would explain why I could find them in the Bangalore airport - the place is pretty far off from the city. I don't expect things to get better for them - I think the common sparrow is gone for good, and the only place where we can see them again is the wilderness. Auf wiedersehen, my friend :)
But, well, these days my mornings are greeted by another avian. It's this guy -

 A lot of people dislike them - particularly because of their habit of pooping all over the place. I have a good reason to hate them for this reason - they pooped all over my shoes and socks when I kept them in the balcony - but I don't. To be fair, that is what a lot of people do too.
The "guttergoo" of pigeons is not as musical to the ears as the chirp - chirp of sparrows. but I always imagine them to be saying
"This is a nice pair of socks..........................for me to poop on!"