Why are birds attracted to airports?
Airports are a wide, open space with a full environment. The attractiveness of vegetation is a balance between food presence, food accessibility, and protection against predators.



And these factors vary a lot for every bird or animal species.

Food
Food accessibility depends on vegetation height and density. Long, dense vegetation will inhibit most hazardous birds/wildlife from moving around, detecting and accessing the food. In addition, birds/wildlife feeding on seeds will avoid the airport if its vegetation is mowed during the flowering season.

Depredators
On the other hand, many species prefer to stay in the open space of short vegetation where they have a wide view to see predators well in advance to enable them to flee on time; and safeguard themselves from predators by hiding or fleeing.

(from AirportBirdControl Blog: 6 most asked questions and answers)