Birds are a constant danger to aircraft which is why they have hawks at San Javier to scare them off.
I'm not sure what measures are taken at Alicante-Elche but whatever they are they did not stop seagulls from damaging a Norwegian plane bound for Munich. The birds crashed into one of the wings of the plane and although the pilot did not suspect that any damage had been caused, he returned to land at the airport rather than risk continuing on.
The seagulls likely came from the nearby rubbish tip at Fontcalent where they flock each day to feed. The council say they will take measures to control the birds in future.