Lovable as the sparrows (Eurasian Tree Sparrows) are...they are not a very intelligent bird, nor a very competitive species. The disappearance of sparrows from our gardens has been noticed by many, who have also claimed that this was evidence of trend towards an eventual extinction of the species.
I think this disappearance of the sparrow is largely because of their failure to compete against some very aggressive and intelligent bird species who have inserted themselves over the last few decades. First there were the Common Mynas who invaded the same ecological niches the sparrows had occupied for years. More recently, the Common Mynas themselves have been displaced by the Javan Mynas. So now these dark brown birds are ubiquitous.
I am not sure what the differences are between the Common Mynas (Indian Mynas; Acridotheres tristis) and the Javan Mynas (Buffalo Mynas; Acridotheres javanicus). Apparently the Common Mynas have got a more striking yellow beak and markings around the eyes....plus they can mimic the human voice.
It's just sad that the sparrows lost out. I am not sure what we can do about it. The mynas are clearly here to stay. I have nothing against them. They are smart and social birds who unfortunately are also very aggressive and brutal in brutal in decimating the sparrows. I suppose biologically they deserve to succeed. But I just wish they can succeed without wiping out the sparrows.
But such is life.....:(. So tragic!
Other readings about the Javan Mynas:
Bird Ecology Study Group: http://besgroup.blogspot.com/2005/12/ubiquitous-javan-myna.html