Yesterday two pigeons began building a nest in a tall Berberis bush in my garden. It is situated near a patio area & they keep flying in & out. I think they have chosen that spot as it is near next doors bird feeding station. Any ideas on how to discourage further pigeons.

Well you could get yourself a peregrine falcon....

Sorry not helpful advice I'm sure, but most biologists on this site would enjoy being able to watch the birds nesting and raising offspring - so you may not get practical suggestions!

My Dad used a water gun to discourage a couple of blackbirds from nesting in a tree near his house. It isn't necessary to actually squirt them, just in their general direction, which they certainly don't like:)