Pigeons are the modern day predators that are disguised as a innocent looking bird. These have replaced the crows and little birds that used to be around neighborhoods and apartment areas. It depends whether you are in an apartment or an individual house.
1.Aviod feeding the birds in and around the apartment. It may sound insenstive but if you are a large apartment complex you will agree.
2.Encourage the presence of other birds to be around the neighborhood, this can be done by having a planned in-expensive green cover, small bird feeders that the pigeons can't peck the grains form.
3. There are pigeon alarm/pest alarms, you can try this.
4. Most apartments go for anit-pigeon netting, based on the quality and the size, it lasts for around 2-3 years before it starts developing holes and become ineffective. If you choose this, then go for the white colours one rather than the dark green one which looks odd from the outside
5.The cost of this is calucated on the area to be covered, the ease of access from the outside and the ease of fixing it. from the exterior.The next is also a very good option as it allows air and sunlight and important it discourages monkeys from barging into the kitchen or apartment living room via the open doors.
6.This is good if it covers the entire open space. After this you can have plastic spikes that can be fixed with synthetic glue on the ledges and parapets in the vicinity of your windows and balconies.
7. Some owners opt for a fine mesh slide door arrangement mounted on aluminium frames to cover the balconies. This prevents the mosquitoes and hence the pigoens, the drawback is that we cannot see much by standing in the balconies.
8.There are also 'Ultrasonic bird repellents that produce a high frequency noise that is very annoying to these birds and humans can't hear it. Once the pigeons know the areas, then it starts avoiding the place. The drawback is some bird lovers would not approve it even though it is not physically harmful to the birds. It would drive off other birds too. It costs anywhere from 2,000-6,000 for individual/personal use sizes.
9. If the place is really small and you do not want to install a net, then you can try distractions like decoy of predatory birds (pariah kites), a slippery spring like roll of rubber or plastic that can be entwined on the railings, this makes it difficult for the pigeons to perch or land. Some even find reflective hanging decor items or balloon, this reflect light on the birds that is annoying.