Where I am we have a policy of constant harassment. The airport employs Bird scaring vehicles with lights ,distress calls,and flare guns. They also use shotguns. As a controller I will hold departures until I can get a vehicle to clear the area,. Bird strikes can have serious consequences. Think the US Airbus which landed in the Hudson river and this one ,which whilst extremely nasty ended well.
You will see that the Thomson hit only ONE bird.