Bird flocks that cause really serious problems to multiple engines are generally no surprise after the fact. The only surprise is to the crew.
Most bird sightings are everyday mother nature to those running airfields. The challenge is to recognize when the environmental combinations are just right for massive flocks directly in the path of a plane.
Forget about simple sounding cover all solutions like dogs, falcons, guns and canons and learn the biological patterns and behaviours that produce these massive flock encounters. For the stuff that's on the airfield (that's where the real safety hazard is) use a little traffic control per active runway. One dedicated person for the one or two hours when the environmental combinations are right is all it should take.