A couple of years ago I rented a ground floor flat in central London for use during the working week. There was a small garden area and the block backed onto a public open space.
I put up a couple of feeders which were the anti squirrel type to deter vermin and larger birds etc. Within a few weeks I received a letter from the managing agents requesting that I remove the feeders as other residents from the upper floors claimed that they were attracting pigeons which they considered a pest as they perched on their balconies. I disputed this vigorously as the pigeons were already there and in fact were nesting on the roof of the building and others nearby. However I had to admit defeat when I was threatened with termination of my lease if I did not comply, even though there was nothing specific in there about bird feeders (they used a clause about other residents right to equal enjoyment of the property or some such)! The management company did not seem interested in the fact that upstairs residents were continually dropping fag ends and other litter from their balconies into MY garden even though I threatened them with the bill for cleaning. So it appears that man made rubbish is ok but nature has no place in the big city. For the record in the 10 months that I spent there (I terminated my lease early and moved out due to the aggro) I recorded great, blue, coal and long tailed tits, redpoll, goldfinch, greenfinch, house sparrow, rose ringed parakeet, blackcap, chiffchaff, jackdaw, collared dove, woodpigeon (ok a few feral pigeons too) all in a 20foot x10 foot patio garden with a few small shrubs and a hawthorn tree less than 1o minutes walk from st Pancras station.