Sparrow : Where have all the sparrows gone !!

Not at all seen in Mumbai , don't know why , where ?
Little bird ,Who's chirpy sound & presence every where including inside home , is no more now , world wide their population incl west is decreasing drastically , means something in environment or our lifestyle affecting them .
They are accurate in  forecasting rain , whenever a  sparrow bath with sand/soil , means definite rain.


Where , any idea , seen lots of pigeons , crows , even kite family  but ...