B y some estimates there are almost 3 million pigeons residing in London, which has the highest pigeon population in the country. Known as “rats with wings”, “flying ashtrays” and “gutter birds”, pigeons do not have popular sentiment on their side. And cities in the UK have an extensive history of attempted pigeon pest control – having tried everything short of an exorcism to remove them – to no avail. London’s best-known victory in the war against pigeons was self-declared, after an operation in Trafalgar Square in the early 2000s . Ken Livingstone’s city government flew two Harris hawks around the area to “deter” pigeons – although the hawks went further than that, killing 121 pigeons in what ended up being a years-long bloodbath. The blitz cost the city £226,000 . Wildlife activists deemed it an act of unimaginable cruelty. And it did little to permanently cut down pigeon populations.…