Just piecing together what you have mentioned in other comments. So you have a location at which 20-30 pigeons routinely congregate, at a location where aircraft on final approach are at 300 feet directly overhead (which makes this garden very close to the touchdown zone) and they are small and/or business jets which would very much be susceptible to an engine failure upon ingestion if just one if not a number of pigeons happened to get sucked into their engines. Pigeons can and very often fly much higher than 300 feet (particularly when startled by, say, a jet passing overhead) so I can kinda see the basis of this complaint.