I think in this case they are just one of natures great adapters, there is not a situation they have not exploited. Ploughed fields, rubbish tips, throw away human food, balcony's and roofs just cliff edges to them for nesting. In a world where nature cannot cope with human expansion its no problem for these birds. They are aggressive and will attack humans for food but this was a another line crossed to me. To nest right on a busy pavement is a new one. I walked up to the bird because I wanted it to move but it didn't, stood right next to it and not bat an eyelid. Only when I put my hand down right next to its head did it move and then just hopped off and straight back on again. I was probably breaking the law but I just wanted to know if it had an egg under it because I was amazed.probably two or three eggs originally, not hard to guess why one left.
I am an admirer of them for the above reasons but they are also a pest round here. I put a canvas tarpaulin over my neighbors shed once and they pecked it all off, why; who knows. I watch them clean up all the meal worms on a bird table and seen them fly iinto a pub and nick a blokes steak, no fear and if they nest on your balcony/roof, the smell and noise is awful. I tried putting a bowl of water on my windowsill for the sparrows and they just knock it off and break it and some of the stuff I have seen them swallow you wouldn't believe.
Yet, a protected bird, why, they are everywhere. One day the red arrows flew over and they all rose up, the sky was black with them and they have started to fly at night, I have noticed that lately, probably competing with the urban foxes for takeaway left overs.