new delhi once a bird that was synonymous with the chirping heard outside every home the house sparrow is today a rare species in the capital despite being delhis state bird and while the others celebrate world sparrow day on tuesday experts in the city are ruing that the brown presence has disappeared due to reduction in urban nesting spaces and the presence of the blue rock pigeon which too is taking over the sparrows nesting areasexperts say it is hard to estimate the numbers left in the city but most sparrows have shifted to the outskirts of delhi said birder nikhil devasar the sparrow concentration has shifted to forests and urban villages outside delhi the fact is urban areas now have fewer trees and greenery where the sparrows can nest of course the blue rock pigeons have also colonised places where sparrows can make nestssince 2010 march 20 has been designated world sparrow day to highlight the decreasing presence of the once common bird in 2012 the sparrow was adopted as the state bird of delhi0102world sparrow day bird lovers keep their relationship alive with these nearextinct avianexperts say the birds act as an ecological indicator and the dwindling numbers signify urban lifestyle changes house sparrows have coexisted with humans but in the last couple of decades they havent been able to keep up with architectural and lifestyle changes explained sohail madan asola centre manager bombay natural history society houses used to be open and there were places for sparrow nests but these have disappeared sparrows are moving to greener areas we are seeing hundreds of them in asola for instancefaiyaz khudsar scientist in charge at the yamuna biodiversity park was almost certain that nonavailability of nesting space was one of the biggest reasons for the flight to the outskirts todays urban constructions are not sparrowfriendly the bird cannot find resting space and finding food is also difficult because availability of insects and worms has reduced due to the use of insecticides and pesticides said khudsarexperts confirmed that the species still lived in substantial numbers in green areas such as lodhi garden sanjay van and the biodiversity parks around the capital in fact dr surya prakash zoologist at jnu asserted the birds could be brought back to the city if feeders and nestboxes were provided in large numbers we have worked in shankar vihar for a few years and seen sparrow population increasing delhi needs efforts of this sort prakash said