Back in Boston in the 1980s nesting baxes for peregrine falcons were installed on the roof tops of office buildings.
From my office on the 20+th floor I would at times be treated to a view of a falcon nose diving and capturing a hapless pigeon. Over time, the result was more peregrine falcons and fewer pigeons.
A problem was that Bostonians did not like seeing a hapless pigeon being torn apart by a falcon.