Anti-roosting spikes might look inhumane, but they’re one of the most effective ways to protect your balcony. They’re not sharp, so you won’t damage the birds.
Pigeons are almost universally considered vermin. Pest control is an expensive way to deal with the problem, as they’ll just dispose of the eggs too.
The easiest way to keep pigeons off a balcony is to set up netting between the railing and roof. It isn't particularly attractive but it gets the job done.
There are plenty of humane ways to keep pigeons off your balcony. They basically all boil down to making it inconvenient or unpleasant.
Visit balconyboss.com for more ideas!