Feed the crows as often as you can. Grow trees so that they can nest. If we lose the crows, we will lose far more than a species of bird.
I have not seen many crows in Delhi or Chandigarh recently. When I asked this question of other people they realized that they had not seen them for months. A look at Google showed that Kanpur lost them in 2011. I hope they are not going the way of the sparrow or the vulture because this is extremely bad news for humans. Crow disappearances cannot be linked to lack of housing or pesticides or even specific chemicals like Diclofenac (which caused the die out of vultures). They eat everything – and I mean everything. So if they have gone, then that means everything around us is so polluted and unsafe that we have to be the next species to go.
413 million birds are what international agencies say we have lost in the last 5 years. 10,000 bird species are now endangered of which 1,200 are now almost extinct. 190 species are extinct.