In the mid 1960's Dr R.K. Murton and his colleagues carried out a study on the effectiveness controlling street pigeons in Salford docks Manchester by lethal methods.
9,000 pigeons had to be killed over three years to reduce a potential population of 2600 birds to one of 1300.
Dr. Murton et al concluded that this method of control was ineffective and expensive .
Sparrows used to be considered a pest and were persecuted much as pigeons are today, but their numbers have deteriorated to such an extent that there is serious concern about the loss of “the cheeky London sparrow”. The reduction in numbers is attributed to loss of habitat.
If there is an aggregation of pigeons in any location it is primarily because there is food available to sustain them and convenient location for them to perch during the day. The availability of nesting sites will also allow the pigeons to maintain their numbers. Killing the pigeons is a waste of public funds as it does not reduce the attractiveness of the area to other pigeons and the dead ones are soon replaced.