The Humane Society of the United States advocates removing food sources, scattering pigeon birth control, covering large areas in netting and preventing pigeons from nesting to control the population. They describe several methods for preventing pigeons from roosting and nesting.
Pigeons are attracted to flat areas and raise up to 12 young per year, which allows them to overrun an area rapidly. Attach bird wires to keep them off of ledges, railings, awnings and rooftops. The bird wires create an unstable springy surface that they dislike. To deal with serious infestations, apply small strips that give off minor electric shocks to popular roosting areas.
OvoControl is a pigeon birth control pill that is scattered on the ground for the pigeons to eat. Once they eat it, they lay unfertilized eggs. Combined with other humane methods of pigeon population control, OvoControl significantly reduces the size of a flock.
Avitrol is advertised as a pigeon repellent, but it is a poison that attacks the nervous system and causes birds to convulse and die. Although Avitrol wipes out small numbers of pigeons at a time, the remaining birds reproduce and replenish the population. Some people use polybutylene gel to deter pigeons, but the Humane Society does not recommend this because the sticky gel captures all types of birds that land, damaging their feathers and sentencing them to a slow death.